fix: mobile adjustments

update: add data-storage warnings to the app

.github/workflows/pypi.yml

@@ -117,7 +117,7 @@ jobs:
           MATURIN_REPOSITORY_URL: "https://test.pypi.org/legacy/"
         with:
           command: upload
-          args: "--skip-existing **/*.whl"
+          args: "--skip-existing **/*.whl **/*.tar.gz"
           working-directory: bindings/python
 
   publish-pypi:
@@ -137,5 +137,5 @@ jobs:
           MATURIN_REPOSITORY_URL: "https://upload.pypi.org/legacy/"
         with:
           command: upload
-          args: "--skip-existing **/*.whl"
+          args: "--skip-existing **/*.whl **/*.tar.gz"
           working-directory: bindings/python

Cargo.lock

@@ -43,6 +43,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "approx"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cab112f0a86d568ea0e627cc1d6be74a1e9cd55214684db5561995f6dad897c6"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "arrayvec"
 version = "0.7.6"
@@ -414,7 +423,7 @@ dependencies = [
 
 [[package]]
 name = "ironcalc"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "bitcode",
  "chrono",
@@ -430,25 +439,25 @@ dependencies = [
 
 [[package]]
 name = "ironcalc_base"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "bitcode",
  "chrono",
  "chrono-tz",
  "csv",
  "js-sys",
- "once_cell",
  "rand",
  "regex",
  "regex-lite",
  "ryu",
  "serde",
  "serde_json",
+ "statrs",
 ]
 
 [[package]]
 name = "ironcalc_nodejs"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "ironcalc",
  "napi",
@@ -721,11 +730,10 @@ dependencies = [
 
 [[package]]
 name = "pyo3"
-version = "0.23.4"
+version = "0.25.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "57fe09249128b3173d092de9523eaa75136bf7ba85e0d69eca241c7939c933cc"
+checksum = "f239d656363bcee73afef85277f1b281e8ac6212a1d42aa90e55b90ed43c47a4"
 dependencies = [
- "cfg-if",
  "indoc",
  "libc",
  "memoffset",
@@ -739,9 +747,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-build-config"
-version = "0.23.4"
+version = "0.25.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1cd3927b5a78757a0d71aa9dff669f903b1eb64b54142a9bd9f757f8fde65fd7"
+checksum = "755ea671a1c34044fa165247aaf6f419ca39caa6003aee791a0df2713d8f1b6d"
 dependencies = [
  "once_cell",
  "target-lexicon",
@@ -749,9 +757,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-ffi"
-version = "0.23.4"
+version = "0.25.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dab6bb2102bd8f991e7749f130a70d05dd557613e39ed2deeee8e9ca0c4d548d"
+checksum = "fc95a2e67091e44791d4ea300ff744be5293f394f1bafd9f78c080814d35956e"
 dependencies = [
  "libc",
  "pyo3-build-config",
@@ -759,9 +767,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros"
-version = "0.23.4"
+version = "0.25.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "91871864b353fd5ffcb3f91f2f703a22a9797c91b9ab497b1acac7b07ae509c7"
+checksum = "a179641d1b93920829a62f15e87c0ed791b6c8db2271ba0fd7c2686090510214"
 dependencies = [
  "proc-macro2",
  "pyo3-macros-backend",
@@ -771,9 +779,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros-backend"
-version = "0.23.4"
+version = "0.25.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "43abc3b80bc20f3facd86cd3c60beed58c3e2aa26213f3cda368de39c60a27e4"
+checksum = "9dff85ebcaab8c441b0e3f7ae40a6963ecea8a9f5e74f647e33fcf5ec9a1e89e"
 dependencies = [
  "heck",
  "proc-macro2",
@@ -784,8 +792,9 @@ dependencies = [
 
 [[package]]
 name = "pyroncalc"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
+ "bitcode",
  "ironcalc",
  "pyo3",
  "serde",
@@ -872,6 +881,12 @@ version = "0.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3cd14fd5e3b777a7422cca79358c57a8f6e3a703d9ac187448d0daf220c2407f"
 
+[[package]]
+name = "rustversion"
+version = "1.0.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a0d197bd2c9dc6e53b84da9556a69ba4cdfab8619eb41a8bd1cc2027a0f6b1d"
+
 [[package]]
 name = "ryu"
 version = "1.0.17"
@@ -960,6 +975,16 @@ version = "0.3.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "38b58827f4464d87d377d175e90bf58eb00fd8716ff0a62f80356b5e61555d0d"
 
+[[package]]
+name = "statrs"
+version = "0.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a3fe7c28c6512e766b0874335db33c94ad7b8f9054228ae1c2abd47ce7d335e"
+dependencies = [
+ "approx",
+ "num-traits",
+]
+
 [[package]]
 name = "subtle"
 version = "2.5.0"
@@ -979,9 +1004,9 @@ dependencies = [
 
 [[package]]
 name = "target-lexicon"
-version = "0.12.16"
+version = "0.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "61c41af27dd6d1e27b1b16b489db798443478cef1f06a660c96db617ba5de3b1"
+checksum = "e502f78cdbb8ba4718f566c418c52bc729126ffd16baee5baa718cf25dd5a69a"
 
 [[package]]
 name = "thiserror"
@@ -1070,7 +1095,7 @@ checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
 [[package]]
 name = "wasm"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "ironcalc_base",
  "serde",
@@ -1081,23 +1106,24 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.92"
+version = "0.2.100"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4be2531df63900aeb2bca0daaaddec08491ee64ceecbee5076636a3b026795a8"
+checksum = "1edc8929d7499fc4e8f0be2262a241556cfc54a0bea223790e71446f2aab1ef5"
 dependencies = [
  "cfg-if",
+ "once_cell",
+ "rustversion",
  "wasm-bindgen-macro",
 ]
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.92"
+version = "0.2.100"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "614d787b966d3989fa7bb98a654e369c762374fd3213d212cfc0251257e747da"
+checksum = "2f0a0651a5c2bc21487bde11ee802ccaf4c51935d0d3d42a6101f98161700bc6"
 dependencies = [
  "bumpalo",
  "log",
- "once_cell",
  "proc-macro2",
  "quote",
  "syn",
@@ -1118,9 +1144,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.92"
+version = "0.2.100"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1f8823de937b71b9460c0c34e25f3da88250760bec0ebac694b49997550d726"
+checksum = "7fe63fc6d09ed3792bd0897b314f53de8e16568c2b3f7982f468c0bf9bd0b407"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -1128,9 +1154,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.92"
+version = "0.2.100"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e94f17b526d0a461a191c78ea52bbce64071ed5c04c9ffe424dcb38f74171bb7"
+checksum = "8ae87ea40c9f689fc23f209965b6fb8a99ad69aeeb0231408be24920604395de"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1141,9 +1167,12 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.92"
+version = "0.2.100"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af190c94f2773fdb3729c55b007a722abb5384da03bc0986df4c289bf5567e96"
+checksum = "1a05d73b933a847d6cccdda8f838a22ff101ad9bf93e33684f39c1f5f0eece3d"
+dependencies = [
+ "unicode-ident",
+]
 
 [[package]]
 name = "wasm-bindgen-test"

Dockerfile

@@ -0,0 +1,93 @@
+FROM rust:latest AS builder
+
+WORKDIR /app
+COPY . .
+
+# Tools + wasm toolchain + Node via nvm
+RUN apt-get update && apt-get install -y --no-install-recommends \
+      bash curl ca-certificates make \
+    && rustup target add wasm32-unknown-unknown \
+    && cargo install wasm-pack \
+    && bash -lc "curl -fsSL https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.3/install.sh | bash -" \
+    && bash -lc '\
+         export NVM_DIR="$HOME/.nvm" && \
+         source "$NVM_DIR/nvm.sh" && \
+         nvm install 22 && nvm alias default 22 && \
+         nroot="$NVM_DIR/versions/node/$(nvm version default)/bin" && \
+         ln -sf "$nroot/node" /usr/local/bin/node && \
+         ln -sf "$nroot/npm"  /usr/local/bin/npm  && \
+         ln -sf "$nroot/npx"  /usr/local/bin/npx \
+       ' \
+    && npm install typescript \
+    && rm -rf /var/lib/apt/lists/*
+
+# build the server
+RUN cargo build --release --manifest-path webapp/app.ironcalc.com/server/Cargo.toml
+
+# build the wasm
+RUN make -C bindings/wasm
+
+# build the widget
+WORKDIR /app/webapp/IronCalc
+RUN npm install && npm run build
+
+# build the frontend app
+WORKDIR /app/webapp/app.ironcalc.com/frontend
+RUN npm install && npm run build
+
+# build the xlsx_2_icalc binary (we don't need the release version here)
+WORKDIR /app/xlsx
+RUN cargo build
+
+WORKDIR /app
+# copy the artifacts to a dist/ directory
+RUN mkdir dist
+RUN mkdir dist/frontend
+RUN cp -r webapp/app.ironcalc.com/frontend/dist/* dist/frontend/
+RUN mkdir dist/server
+RUN cp webapp/app.ironcalc.com/server/target/release/ironcalc_server dist/server/
+RUN cp webapp/app.ironcalc.com/server/Rocket.toml dist/server/
+RUN cp webapp/app.ironcalc.com/server/ironcalc.sqlite dist/server/
+
+# Create ic files in docs
+RUN mkdir -p dist/frontend/models
+
+# Loop over all xlsx files in xlsx/tests/docs & templates and convert them to .ic
+RUN bash -lc 'set -euo pipefail; \
+  mkdir -p dist/frontend/models; \
+  shopt -s nullglob; \
+  for xlsx_file in xlsx/tests/docs/*.xlsx; do \
+    base_name="${xlsx_file##*/}"; base_name="${base_name%.xlsx}"; \
+    ./target/debug/xlsx_2_icalc "$xlsx_file" "dist/frontend/models/${base_name}.ic"; \
+  done; \
+  for xlsx_file in xlsx/tests/templates/*.xlsx; do \
+    base_name="${xlsx_file##*/}"; base_name="${base_name%.xlsx}"; \
+    ./target/debug/xlsx_2_icalc "$xlsx_file" "dist/frontend/models/${base_name}.ic"; \
+  done'
+
+# ---------- server runtime ----------
+FROM debian:bookworm-slim AS server-runtime
+RUN apt-get update && apt-get install -y --no-install-recommends ca-certificates && \
+    rm -rf /var/lib/apt/lists/*
+WORKDIR /app
+# Copy EVERYTHING you put in dist/server (binary + Rocket.toml + DB)
+COPY --from=builder /app/dist/server/ ./
+# Make sure Rocket binds to the container IP; explicitly point to the config file
+ENV ROCKET_ADDRESS=0.0.0.0 \
+    ROCKET_PORT=8000 \
+    ROCKET_CONFIG=/app/Rocket.toml
+EXPOSE 8000
+# Run from /app so relative paths in Rocket.toml/DB work
+CMD ["./ironcalc_server"]
+
+# ---------- caddy runtime (serves frontend + reverse-proxy /api) ----------
+FROM caddy:latest AS caddy-runtime
+
+WORKDIR /srv
+
+# Copy the frontend build output to /srv
+COPY --from=builder /app/dist/frontend/ /srv/
+
+# Copy the Caddyfile
+COPY --from=builder /app/webapp/app.ironcalc.com/Caddyfile.compose /etc/caddy/Caddyfile
+

README.md

@@ -31,7 +31,17 @@ This repository contains the main engine and the xlsx reader and writer.
 
 Programmed in Rust, you will be able to use it from a variety of programming languages like Python, JavaScript (wasm), nodejs and possibly R, Julia or Go.
 
-We will build different _skins_: in the terminal, as a desktop application or use it in you own web application.
+We will build different _skins_: in the terminal, as a desktop application or use it in your own web application.
+
+# Docker
+
+If you have docker installed just run:
+
+```bash
+docker compose up --build
+```
+
+head over to <http://localhost:2080> to test the application.
 
 # Building
 
@@ -84,7 +94,7 @@ And then use this code in `main.rs`:
 
 ```rust
 use ironcalc::{
-    base::{expressions::utils::number_to_column, model::Model},
+    base::{expressions::utils::number_to_column, Model},
     export::save_to_xlsx,
 };
 

base/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ironcalc_base"
-version = "0.5.0"
+version = "0.6.0"
 authors = ["Nicolás Hatcher <nicolas@theuniverse.today>"]
 edition = "2021"
 homepage = "https://www.ironcalc.com"
@@ -17,9 +17,9 @@ chrono = "0.4"
 chrono-tz = "0.10"
 regex = { version = "1.0", optional = true}
 regex-lite = { version = "0.1.6", optional = true}
-once_cell = "1.16.0"
 bitcode = "0.6.3"
 csv = "1.3.0"
+statrs = { version = "0.18.0", default-features = false, features = [] }
 
 [features]
 default = ["use_regex_full"]

base/src/actions.rs

@@ -212,6 +212,12 @@ impl Model {
         if column_count <= 0 {
             return Err("Please use insert columns instead".to_string());
         }
+        if !(1..=LAST_COLUMN).contains(&column) {
+            return Err(format!("Column number '{column}' is not valid."));
+        }
+        if column + column_count - 1 > LAST_COLUMN {
+            return Err("Cannot delete columns beyond the last column of the sheet".to_string());
+        }
 
         // first column being deleted
         let column_start = column;
@@ -384,6 +390,13 @@ impl Model {
         if row_count <= 0 {
             return Err("Please use insert rows instead".to_string());
         }
+        if !(1..=LAST_ROW).contains(&row) {
+            return Err(format!("Row number '{row}' is not valid."));
+        }
+        if row + row_count - 1 > LAST_ROW {
+            return Err("Cannot delete rows beyond the last row of the sheet".to_string());
+        }
+
         // Move cells
         let worksheet = &self.workbook.worksheet(sheet)?;
         let mut all_rows: Vec<i32> = worksheet.sheet_data.keys().copied().collect();
@@ -444,7 +457,7 @@ impl Model {
     ///    * Column is one of the extremes of the range. The new extreme would be target_column.
     ///      Range is then normalized
     ///    * Any other case, range is left unchanged.
-    ///      NOTE: This does NOT move the data in the columns or move the colum styles
+    ///      NOTE: This moves the data and column styles along with the formulas
     pub fn move_column_action(
         &mut self,
         sheet: u32,
@@ -460,7 +473,70 @@ impl Model {
             return Err("Initial column out of boundaries".to_string());
         }
 
-        // TODO: Add the actual displacement of data and styles
+        if delta == 0 {
+            return Ok(());
+        }
+
+        // Preserve cell contents, width and style of the column being moved
+        let original_refs = self
+            .workbook
+            .worksheet(sheet)?
+            .column_cell_references(column)?;
+        let mut original_cells = Vec::new();
+        for r in &original_refs {
+            let cell = self
+                .workbook
+                .worksheet(sheet)?
+                .cell(r.row, column)
+                .ok_or("Expected Cell to exist")?;
+            let style_idx = cell.get_style();
+            let formula_or_value = self
+                .get_cell_formula(sheet, r.row, column)?
+                .unwrap_or_else(|| cell.get_text(&self.workbook.shared_strings, &self.language));
+            original_cells.push((r.row, formula_or_value, style_idx));
+            self.cell_clear_all(sheet, r.row, column)?;
+        }
+
+        let width = self.workbook.worksheet(sheet)?.get_column_width(column)?;
+        let style = self.workbook.worksheet(sheet)?.get_column_style(column)?;
+
+        if delta > 0 {
+            for c in column + 1..=target_column {
+                let refs = self.workbook.worksheet(sheet)?.column_cell_references(c)?;
+                for r in refs {
+                    self.move_cell(sheet, r.row, c, r.row, c - 1)?;
+                }
+
+                let w = self.workbook.worksheet(sheet)?.get_column_width(c)?;
+                let s = self.workbook.worksheet(sheet)?.get_column_style(c)?;
+                self.workbook
+                    .worksheet_mut(sheet)?
+                    .set_column_width_and_style(c - 1, w, s)?;
+            }
+        } else {
+            for c in (target_column..=column - 1).rev() {
+                let refs = self.workbook.worksheet(sheet)?.column_cell_references(c)?;
+                for r in refs {
+                    self.move_cell(sheet, r.row, c, r.row, c + 1)?;
+                }
+
+                let w = self.workbook.worksheet(sheet)?.get_column_width(c)?;
+                let s = self.workbook.worksheet(sheet)?.get_column_style(c)?;
+                self.workbook
+                    .worksheet_mut(sheet)?
+                    .set_column_width_and_style(c + 1, w, s)?;
+            }
+        }
+
+        for (r, value, style_idx) in original_cells {
+            self.set_user_input(sheet, r, target_column, value)?;
+            self.workbook
+                .worksheet_mut(sheet)?
+                .set_cell_style(r, target_column, style_idx)?;
+        }
+        self.workbook
+            .worksheet_mut(sheet)?
+            .set_column_width_and_style(target_column, width, style)?;
 
         // Update all formulas in the workbook
         self.displace_cells(
@@ -473,4 +549,88 @@ impl Model {
 
         Ok(())
     }
+
+    /// Displaces cells due to a move row action
+    /// from initial_row to target_row = initial_row + row_delta
+    /// References will be updated following the same rules as move_column_action
+    /// NOTE: This moves the data and row styles along with the formulas
+    pub fn move_row_action(&mut self, sheet: u32, row: i32, delta: i32) -> Result<(), String> {
+        // Check boundaries
+        let target_row = row + delta;
+        if !(1..=LAST_ROW).contains(&target_row) {
+            return Err("Target row out of boundaries".to_string());
+        }
+        if !(1..=LAST_ROW).contains(&row) {
+            return Err("Initial row out of boundaries".to_string());
+        }
+
+        if delta == 0 {
+            return Ok(());
+        }
+
+        let original_cols = self.get_columns_for_row(sheet, row, false)?;
+        let mut original_cells = Vec::new();
+        for c in &original_cols {
+            let cell = self
+                .workbook
+                .worksheet(sheet)?
+                .cell(row, *c)
+                .ok_or("Expected Cell to exist")?;
+            let style_idx = cell.get_style();
+            let formula_or_value = self
+                .get_cell_formula(sheet, row, *c)?
+                .unwrap_or_else(|| cell.get_text(&self.workbook.shared_strings, &self.language));
+            original_cells.push((*c, formula_or_value, style_idx));
+            self.cell_clear_all(sheet, row, *c)?;
+        }
+
+        if delta > 0 {
+            for r in row + 1..=target_row {
+                let cols = self.get_columns_for_row(sheet, r, false)?;
+                for c in cols {
+                    self.move_cell(sheet, r, c, r - 1, c)?;
+                }
+            }
+        } else {
+            for r in (target_row..=row - 1).rev() {
+                let cols = self.get_columns_for_row(sheet, r, false)?;
+                for c in cols {
+                    self.move_cell(sheet, r, c, r + 1, c)?;
+                }
+            }
+        }
+
+        for (c, value, style_idx) in original_cells {
+            self.set_user_input(sheet, target_row, c, value)?;
+            self.workbook
+                .worksheet_mut(sheet)?
+                .set_cell_style(target_row, c, style_idx)?;
+        }
+
+        let worksheet = &mut self.workbook.worksheet_mut(sheet)?;
+        let mut new_rows = Vec::new();
+        for r in worksheet.rows.iter() {
+            if r.r == row {
+                let mut nr = r.clone();
+                nr.r = target_row;
+                new_rows.push(nr);
+            } else if delta > 0 && r.r > row && r.r <= target_row {
+                let mut nr = r.clone();
+                nr.r -= 1;
+                new_rows.push(nr);
+            } else if delta < 0 && r.r < row && r.r >= target_row {
+                let mut nr = r.clone();
+                nr.r += 1;
+                new_rows.push(nr);
+            } else {
+                new_rows.push(r.clone());
+            }
+        }
+        worksheet.rows = new_rows;
+
+        // Update all formulas in the workbook
+        self.displace_cells(&(DisplaceData::RowMove { sheet, row, delta }))?;
+
+        Ok(())
+    }
 }

base/src/cast.rs

@@ -5,6 +5,7 @@ use crate::{
         token::Error,
         types::CellReferenceIndex,
     },
+    formatter::format::parse_formatted_number,
     model::Model,
 };
 
@@ -14,6 +15,23 @@ pub(crate) enum NumberOrArray {
 }
 
 impl Model {
+    pub(crate) fn cast_number(&self, s: &str) -> Option<f64> {
+        match s.trim().parse::<f64>() {
+            Ok(f) => Some(f),
+            _ => {
+                let currency = &self.locale.currency.symbol;
+                let mut currencies = vec!["$", "€"];
+                if !currencies.iter().any(|e| *e == currency) {
+                    currencies.push(currency);
+                }
+                // Try to parse as a formatted number (e.g., dates, currencies, percentages)
+                if let Ok((v, _number_format)) = parse_formatted_number(s, &currencies) {
+                    return Some(v);
+                }
+                None
+            }
+        }
+    }
     pub(crate) fn get_number_or_array(
         &mut self,
         node: &Node,
@@ -21,9 +39,9 @@ impl Model {
     ) -> Result<NumberOrArray, CalcResult> {
         match self.evaluate_node_in_context(node, cell) {
             CalcResult::Number(f) => Ok(NumberOrArray::Number(f)),
-            CalcResult::String(s) => match s.parse::<f64>() {
+            CalcResult::String(s) => match self.cast_number(&s) {
-                Ok(f) => Ok(NumberOrArray::Number(f)),
+                Some(f) => Ok(NumberOrArray::Number(f)),
-                _ => Err(CalcResult::new_error(
+                None => Err(CalcResult::new_error(
                     Error::VALUE,
                     cell,
                     "Expecting number".to_string(),
@@ -89,16 +107,16 @@ impl Model {
         self.cast_to_number(result, cell)
     }
 
-    fn cast_to_number(
+    pub(crate) fn cast_to_number(
         &mut self,
         result: CalcResult,
         cell: CellReferenceIndex,
     ) -> Result<f64, CalcResult> {
         match result {
             CalcResult::Number(f) => Ok(f),
-            CalcResult::String(s) => match s.parse::<f64>() {
+            CalcResult::String(s) => match self.cast_number(&s) {
-                Ok(f) => Ok(f),
+                Some(f) => Ok(f),
-                _ => Err(CalcResult::new_error(
+                None => Err(CalcResult::new_error(
                     Error::VALUE,
                     cell,
                     "Expecting number".to_string(),
@@ -159,7 +177,7 @@ impl Model {
         // FIXME: I think when casting a number we should convert it to_precision(x, 15)
         // See function Exact
         match result {
-            CalcResult::Number(f) => Ok(format!("{}", f)),
+            CalcResult::Number(f) => Ok(format!("{f}")),
             CalcResult::String(s) => Ok(s),
             CalcResult::Boolean(f) => {
                 if f {

base/src/expressions/lexer/mod.rs

@@ -142,7 +142,7 @@ impl Lexer {
     pub fn expect(&mut self, tk: TokenType) -> Result<()> {
         let nt = self.next_token();
         if mem::discriminant(&nt) != mem::discriminant(&tk) {
-            return Err(self.set_error(&format!("Error, expected {:?}", tk), self.position));
+            return Err(self.set_error(&format!("Error, expected {tk:?}"), self.position));
         }
         Ok(())
     }
@@ -314,6 +314,9 @@ impl Lexer {
                             } else if name_upper == self.language.booleans.r#false {
                                 return TokenType::Boolean(false);
                             }
+                            if self.peek_char() == Some('(') {
+                                return TokenType::Ident(name);
+                            }
                             if self.mode == LexerMode::A1 {
                                 let parsed_reference = utils::parse_reference_a1(&name_upper);
                                 if parsed_reference.is_some()
@@ -511,7 +514,7 @@ impl Lexer {
         self.position = position;
         chars.parse::<i32>().map_err(|_| LexerError {
             position,
-            message: format!("Failed to parse to int: {}", chars),
+            message: format!("Failed to parse to int: {chars}"),
         })
     }
 
@@ -572,9 +575,7 @@ impl Lexer {
         }
         self.position = position;
         match chars.parse::<f64>() {
-            Err(_) => {
+            Err(_) => Err(self.set_error(&format!("Failed to parse to double: {chars}"), position)),
-                Err(self.set_error(&format!("Failed to parse to double: {}", chars), position))
-            }
             Ok(v) => Ok(v),
         }
     }

base/src/expressions/lexer/ranges.rs

@@ -148,15 +148,16 @@ impl Lexer {
                     let row_left = match row_left.parse::<i32>() {
                         Ok(n) => n,
                         Err(_) => {
-                            return Err(self
+                            return Err(
-                                .set_error(&format!("Failed parsing row {}", row_left), position))
+                                self.set_error(&format!("Failed parsing row {row_left}"), position)
+                            )
                         }
                     };
                     let row_right = match row_right.parse::<i32>() {
                         Ok(n) => n,
                         Err(_) => {
                             return Err(self
-                                .set_error(&format!("Failed parsing row {}", row_right), position))
+                                .set_error(&format!("Failed parsing row {row_right}"), position))
                         }
                     };
                     if row_left > LAST_ROW {

base/src/expressions/lexer/test/test_common.rs

@@ -1,5 +1,6 @@
 #![allow(clippy::unwrap_used)]
 
+use crate::expressions::utils::column_to_number;
 use crate::language::get_language;
 use crate::locale::get_locale;
 
@@ -685,3 +686,29 @@ fn test_comparisons() {
     assert_eq!(lx.next_token(), Number(7.0));
     assert_eq!(lx.next_token(), EOF);
 }
+
+#[test]
+fn test_log10_is_cell_reference() {
+    let mut lx = new_lexer("LOG10", true);
+    assert_eq!(
+        lx.next_token(),
+        Reference {
+            sheet: None,
+            column: column_to_number("LOG").unwrap(),
+            row: 10,
+            absolute_column: false,
+            absolute_row: false,
+        }
+    );
+    assert_eq!(lx.next_token(), EOF);
+}
+
+#[test]
+fn test_log10_is_function() {
+    let mut lx = new_lexer("LOG10(100)", true);
+    assert_eq!(lx.next_token(), Ident("LOG10".to_string()));
+    assert_eq!(lx.next_token(), LeftParenthesis);
+    assert_eq!(lx.next_token(), Number(100.0));
+    assert_eq!(lx.next_token(), RightParenthesis);
+    assert_eq!(lx.next_token(), EOF);
+}

base/src/expressions/parser/mod.rs

@@ -717,7 +717,7 @@ impl Parser {
                         return Node::ParseErrorKind {
                             formula: self.lexer.get_formula(),
                             position: 0,
-                            message: "sheet not found".to_string(),
+                            message: format!("sheet not found: {}", context.sheet),
                         };
                     }
                 };
@@ -828,7 +828,7 @@ impl Parser {
             | TokenType::Percent => Node::ParseErrorKind {
                 formula: self.lexer.get_formula(),
                 position: 0,
-                message: format!("Unexpected token: '{:?}'", next_token),
+                message: format!("Unexpected token: '{next_token:?}'"),
             },
             TokenType::LeftBracket => Node::ParseErrorKind {
                 formula: self.lexer.get_formula(),
@@ -850,7 +850,7 @@ impl Parser {
                         return Node::ParseErrorKind {
                             formula: self.lexer.get_formula(),
                             position: 0,
-                            message: "sheet not found".to_string(),
+                            message: format!("sheet not found: {}", context.sheet),
                         };
                     }
                 };
@@ -878,7 +878,7 @@ impl Parser {
                         return Node::ParseErrorKind {
                             formula: self.lexer.get_formula(),
                             position: 0,
-                            message: "sheet not found".to_string(),
+                            message: format!("table sheet not found: {}", table.sheet_name),
                         };
                     }
                 };

base/src/expressions/parser/move_formula.rs

@@ -53,24 +53,24 @@ fn move_function(name: &str, args: &Vec<Node>, move_context: &MoveContext) -> St
             arguments = to_string_moved(el, move_context);
         }
     }
-    format!("{}({})", name, arguments)
+    format!("{name}({arguments})")
 }
 
 pub(crate) fn to_string_array_node(node: &ArrayNode) -> String {
     match node {
-        ArrayNode::Boolean(value) => format!("{}", value).to_ascii_uppercase(),
+        ArrayNode::Boolean(value) => format!("{value}").to_ascii_uppercase(),
         ArrayNode::Number(number) => to_excel_precision_str(*number),
-        ArrayNode::String(value) => format!("\"{}\"", value),
+        ArrayNode::String(value) => format!("\"{value}\""),
-        ArrayNode::Error(kind) => format!("{}", kind),
+        ArrayNode::Error(kind) => format!("{kind}"),
     }
 }
 
 fn to_string_moved(node: &Node, move_context: &MoveContext) -> String {
     use self::Node::*;
     match node {
-        BooleanKind(value) => format!("{}", value).to_ascii_uppercase(),
+        BooleanKind(value) => format!("{value}").to_ascii_uppercase(),
         NumberKind(number) => to_excel_precision_str(*number),
-        StringKind(value) => format!("\"{}\"", value),
+        StringKind(value) => format!("\"{value}\""),
         ReferenceKind {
             sheet_name,
             sheet_index,
@@ -241,7 +241,7 @@ fn to_string_moved(node: &Node, move_context: &MoveContext) -> String {
                 full_row,
                 full_column,
             );
-            format!("{}:{}", s1, s2)
+            format!("{s1}:{s2}")
         }
         WrongReferenceKind {
             sheet_name,
@@ -325,7 +325,7 @@ fn to_string_moved(node: &Node, move_context: &MoveContext) -> String {
                 full_row,
                 full_column,
             );
-            format!("{}:{}", s1, s2)
+            format!("{s1}:{s2}")
         }
         OpRangeKind { left, right } => format!(
             "{}:{}",
@@ -358,7 +358,7 @@ fn to_string_moved(node: &Node, move_context: &MoveContext) -> String {
                 }
                 _ => to_string_moved(right, move_context),
             };
-            format!("{}{}{}", x, kind, y)
+            format!("{x}{kind}{y}")
         }
         OpPowerKind { left, right } => format!(
             "{}^{}",
@@ -403,7 +403,7 @@ fn to_string_moved(node: &Node, move_context: &MoveContext) -> String {
             }
 
             // Enclose the whole matrix in braces
-            format!("{{{}}}", matrix_string)
+            format!("{{{matrix_string}}}")
         }
         DefinedNameKind((name, ..)) => name.to_string(),
         TableNameKind(name) => name.to_string(),
@@ -418,7 +418,7 @@ fn to_string_moved(node: &Node, move_context: &MoveContext) -> String {
             OpUnary::Minus => format!("-{}", to_string_moved(right, move_context)),
             OpUnary::Percentage => format!("{}%", to_string_moved(right, move_context)),
         },
-        ErrorKind(kind) => format!("{}", kind),
+        ErrorKind(kind) => format!("{kind}"),
         ParseErrorKind {
             formula,
             message: _,

base/src/expressions/parser/static_analysis.rs

@@ -2,15 +2,19 @@ use crate::functions::Function;
 
 use super::Node;
 
-use once_cell::sync::Lazy;
 use regex::Regex;
+use std::sync::OnceLock;
+
+static RANGE_REFERENCE_REGEX: OnceLock<Regex> = OnceLock::new();
 
 #[allow(clippy::expect_used)]
-static RE: Lazy<Regex> =
+fn get_re() -> &'static Regex {
-    Lazy::new(|| Regex::new(r":[A-Z]*[0-9]*$").expect("Regex is known to be valid"));
+    RANGE_REFERENCE_REGEX
+        .get_or_init(|| Regex::new(r":[A-Z]*[0-9]*$").expect("Regex is known to be valid"))
+}
 
 fn is_range_reference(s: &str) -> bool {
-    RE.is_match(s)
+    get_re().is_match(s)
 }
 
 /*
@@ -337,7 +341,8 @@ fn static_analysis_offset(args: &[Node]) -> StaticResult {
         }
         _ => return StaticResult::Unknown,
     };
-    StaticResult::Unknown
+    // Both height and width are explicitly 1, so OFFSET will return a single cell
+    StaticResult::Scalar
 }
 
 // fn static_analysis_choose(_args: &[Node]) -> StaticResult {
@@ -571,6 +576,37 @@ fn args_signature_xnpv(arg_count: usize) -> Vec<Signature> {
     }
 }
 
+// NETWORKDAYS(start_date, end_date, [holidays])
+// Parameters: start_date (scalar), end_date (scalar), holidays (optional vector)
+fn args_signature_networkdays(arg_count: usize) -> Vec<Signature> {
+    if arg_count == 2 {
+        vec![Signature::Scalar, Signature::Scalar]
+    } else if arg_count == 3 {
+        vec![Signature::Scalar, Signature::Scalar, Signature::Vector]
+    } else {
+        vec![Signature::Error; arg_count]
+    }
+}
+
+// NETWORKDAYS.INTL(start_date, end_date, [weekend], [holidays])
+// Parameters: start_date (scalar), end_date (scalar), weekend (optional scalar), holidays (optional vector)
+fn args_signature_networkdays_intl(arg_count: usize) -> Vec<Signature> {
+    if arg_count == 2 {
+        vec![Signature::Scalar, Signature::Scalar]
+    } else if arg_count == 3 {
+        vec![Signature::Scalar, Signature::Scalar, Signature::Scalar]
+    } else if arg_count == 4 {
+        vec![
+            Signature::Scalar,
+            Signature::Scalar,
+            Signature::Scalar,
+            Signature::Vector,
+        ]
+    } else {
+        vec![Signature::Error; arg_count]
+    }
+}
+
 // FIXME: This is terrible duplications of efforts. We use the signature in at least three different places:
 // 1. When computing the function
 // 2. Checking the arguments to see if we need to insert the implicit intersection operator
@@ -605,6 +641,9 @@ fn get_function_args_signature(kind: &Function, arg_count: usize) -> Vec<Signatu
         Function::Choose => vec![Signature::Scalar; arg_count],
         Function::Column => args_signature_row(arg_count),
         Function::Columns => args_signature_one_vector(arg_count),
+        Function::Ln => args_signature_scalars(arg_count, 1, 0),
+        Function::Log => args_signature_scalars(arg_count, 1, 1),
+        Function::Log10 => args_signature_scalars(arg_count, 1, 0),
         Function::Cos => args_signature_scalars(arg_count, 1, 0),
         Function::Cosh => args_signature_scalars(arg_count, 1, 0),
         Function::Max => vec![Signature::Vector; arg_count],
@@ -683,13 +722,28 @@ fn get_function_args_signature(kind: &Function, arg_count: usize) -> Vec<Signatu
         Function::Maxifs => vec![Signature::Vector; arg_count],
         Function::Minifs => vec![Signature::Vector; arg_count],
         Function::Date => args_signature_scalars(arg_count, 3, 0),
+        Function::Datedif => args_signature_scalars(arg_count, 3, 0),
+        Function::Datevalue => args_signature_scalars(arg_count, 1, 0),
         Function::Day => args_signature_scalars(arg_count, 1, 0),
         Function::Edate => args_signature_scalars(arg_count, 2, 0),
         Function::Eomonth => args_signature_scalars(arg_count, 2, 0),
         Function::Month => args_signature_scalars(arg_count, 1, 0),
+        Function::Time => args_signature_scalars(arg_count, 3, 0),
+        Function::Timevalue => args_signature_scalars(arg_count, 1, 0),
+        Function::Hour => args_signature_scalars(arg_count, 1, 0),
+        Function::Minute => args_signature_scalars(arg_count, 1, 0),
+        Function::Second => args_signature_scalars(arg_count, 1, 0),
         Function::Now => args_signature_no_args(arg_count),
         Function::Today => args_signature_no_args(arg_count),
         Function::Year => args_signature_scalars(arg_count, 1, 0),
+        Function::Days => args_signature_scalars(arg_count, 2, 0),
+        Function::Days360 => args_signature_scalars(arg_count, 2, 1),
+        Function::Weekday => args_signature_scalars(arg_count, 1, 1),
+        Function::Weeknum => args_signature_scalars(arg_count, 1, 1),
+        Function::Workday => args_signature_scalars(arg_count, 2, 1),
+        Function::WorkdayIntl => args_signature_scalars(arg_count, 2, 2),
+        Function::Yearfrac => args_signature_scalars(arg_count, 2, 1),
+        Function::Isoweeknum => args_signature_scalars(arg_count, 1, 0),
         Function::Cumipmt => args_signature_scalars(arg_count, 6, 0),
         Function::Cumprinc => args_signature_scalars(arg_count, 6, 0),
         Function::Db => args_signature_scalars(arg_count, 4, 1),
@@ -778,6 +832,63 @@ fn get_function_args_signature(kind: &Function, arg_count: usize) -> Vec<Signatu
         Function::Formulatext => args_signature_scalars(arg_count, 1, 0),
         Function::Unicode => args_signature_scalars(arg_count, 1, 0),
         Function::Geomean => vec![Signature::Vector; arg_count],
+        Function::Networkdays => args_signature_networkdays(arg_count),
+        Function::NetworkdaysIntl => args_signature_networkdays_intl(arg_count),
+        Function::Acot => args_signature_scalars(arg_count, 1, 0),
+        Function::Acoth => args_signature_scalars(arg_count, 1, 0),
+        Function::Cot => args_signature_scalars(arg_count, 1, 0),
+        Function::Coth => args_signature_scalars(arg_count, 1, 0),
+        Function::Csc => args_signature_scalars(arg_count, 1, 0),
+        Function::Csch => args_signature_scalars(arg_count, 1, 0),
+        Function::Sec => args_signature_scalars(arg_count, 1, 0),
+        Function::Sech => args_signature_scalars(arg_count, 1, 0),
+        Function::Exp => args_signature_scalars(arg_count, 1, 0),
+        Function::Fact => args_signature_scalars(arg_count, 1, 0),
+        Function::Factdouble => args_signature_scalars(arg_count, 1, 0),
+        Function::Sign => args_signature_scalars(arg_count, 1, 0),
+        Function::Radians => args_signature_scalars(arg_count, 1, 0),
+        Function::Degrees => args_signature_scalars(arg_count, 1, 0),
+        Function::Int => args_signature_scalars(arg_count, 1, 0),
+        Function::Even => args_signature_scalars(arg_count, 1, 0),
+        Function::Odd => args_signature_scalars(arg_count, 1, 0),
+        Function::Ceiling => args_signature_scalars(arg_count, 2, 0),
+        Function::CeilingMath => args_signature_scalars(arg_count, 1, 2),
+        Function::CeilingPrecise => args_signature_scalars(arg_count, 1, 1),
+        Function::Floor => args_signature_scalars(arg_count, 2, 0),
+        Function::FloorMath => args_signature_scalars(arg_count, 1, 2),
+        Function::FloorPrecise => args_signature_scalars(arg_count, 1, 1),
+        Function::IsoCeiling => args_signature_scalars(arg_count, 1, 1),
+        Function::Mod => args_signature_scalars(arg_count, 2, 0),
+        Function::Quotient => args_signature_scalars(arg_count, 2, 0),
+        Function::Mround => args_signature_scalars(arg_count, 2, 0),
+        Function::Trunc => args_signature_scalars(arg_count, 1, 1),
+        Function::Gcd => vec![Signature::Vector; arg_count],
+        Function::Lcm => vec![Signature::Vector; arg_count],
+        Function::Base => args_signature_scalars(arg_count, 2, 1),
+        Function::Decimal => args_signature_scalars(arg_count, 2, 0),
+        Function::Roman => args_signature_scalars(arg_count, 1, 1),
+        Function::Arabic => args_signature_scalars(arg_count, 1, 0),
+        Function::Combin => args_signature_scalars(arg_count, 2, 0),
+        Function::Combina => args_signature_scalars(arg_count, 2, 0),
+        Function::Sumsq => vec![Signature::Vector; arg_count],
+
+        Function::N => args_signature_scalars(arg_count, 1, 0),
+        Function::Sheets => args_signature_scalars(arg_count, 0, 1),
+        Function::Cell => args_signature_scalars(arg_count, 1, 1),
+        Function::Info => args_signature_scalars(arg_count, 1, 1),
+
+        Function::Daverage => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dcount => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dget => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dmax => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dmin => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dsum => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dcounta => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dproduct => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dstdev => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dvar => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dvarp => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
+        Function::Dstdevp => vec![Signature::Vector, Signature::Scalar, Signature::Vector],
     }
 }
 
@@ -816,6 +927,9 @@ fn static_analysis_on_function(kind: &Function, args: &[Node]) -> StaticResult {
         Function::Round => scalar_arguments(args),
         Function::Rounddown => scalar_arguments(args),
         Function::Roundup => scalar_arguments(args),
+        Function::Ln => scalar_arguments(args),
+        Function::Log => scalar_arguments(args),
+        Function::Log10 => scalar_arguments(args),
         Function::Sin => scalar_arguments(args),
         Function::Sinh => scalar_arguments(args),
         Function::Sqrt => scalar_arguments(args),
@@ -886,12 +1000,27 @@ fn static_analysis_on_function(kind: &Function, args: &[Node]) -> StaticResult {
         Function::Maxifs => not_implemented(args),
         Function::Minifs => not_implemented(args),
         Function::Date => not_implemented(args),
+        Function::Datedif => not_implemented(args),
+        Function::Datevalue => not_implemented(args),
         Function::Day => not_implemented(args),
         Function::Edate => not_implemented(args),
         Function::Month => not_implemented(args),
+        Function::Time => not_implemented(args),
+        Function::Timevalue => not_implemented(args),
+        Function::Hour => not_implemented(args),
+        Function::Minute => not_implemented(args),
+        Function::Second => not_implemented(args),
         Function::Now => not_implemented(args),
         Function::Today => not_implemented(args),
         Function::Year => not_implemented(args),
+        Function::Days => not_implemented(args),
+        Function::Days360 => not_implemented(args),
+        Function::Weekday => not_implemented(args),
+        Function::Weeknum => not_implemented(args),
+        Function::Workday => not_implemented(args),
+        Function::WorkdayIntl => not_implemented(args),
+        Function::Yearfrac => not_implemented(args),
+        Function::Isoweeknum => not_implemented(args),
         Function::Cumipmt => not_implemented(args),
         Function::Cumprinc => not_implemented(args),
         Function::Db => not_implemented(args),
@@ -980,5 +1109,61 @@ fn static_analysis_on_function(kind: &Function, args: &[Node]) -> StaticResult {
         Function::Eomonth => scalar_arguments(args),
         Function::Formulatext => not_implemented(args),
         Function::Geomean => not_implemented(args),
+        Function::Networkdays => not_implemented(args),
+        Function::NetworkdaysIntl => not_implemented(args),
+        Function::Acot => scalar_arguments(args),
+        Function::Acoth => scalar_arguments(args),
+        Function::Cot => scalar_arguments(args),
+        Function::Coth => scalar_arguments(args),
+        Function::Csc => scalar_arguments(args),
+        Function::Csch => scalar_arguments(args),
+        Function::Sec => scalar_arguments(args),
+        Function::Sech => scalar_arguments(args),
+        Function::Exp => scalar_arguments(args),
+        Function::Fact => scalar_arguments(args),
+        Function::Factdouble => scalar_arguments(args),
+        Function::Sign => scalar_arguments(args),
+        Function::Radians => scalar_arguments(args),
+        Function::Degrees => scalar_arguments(args),
+        Function::Int => scalar_arguments(args),
+        Function::Even => scalar_arguments(args),
+        Function::Odd => scalar_arguments(args),
+        Function::Ceiling => scalar_arguments(args),
+        Function::CeilingMath => scalar_arguments(args),
+        Function::CeilingPrecise => scalar_arguments(args),
+        Function::Floor => scalar_arguments(args),
+        Function::FloorMath => scalar_arguments(args),
+        Function::FloorPrecise => scalar_arguments(args),
+        Function::IsoCeiling => scalar_arguments(args),
+        Function::Mod => scalar_arguments(args),
+        Function::Quotient => scalar_arguments(args),
+        Function::Mround => scalar_arguments(args),
+        Function::Trunc => scalar_arguments(args),
+        Function::Gcd => not_implemented(args),
+        Function::Lcm => not_implemented(args),
+        Function::Base => scalar_arguments(args),
+        Function::Decimal => scalar_arguments(args),
+        Function::Roman => scalar_arguments(args),
+        Function::Arabic => scalar_arguments(args),
+        Function::Combin => scalar_arguments(args),
+        Function::Combina => scalar_arguments(args),
+        Function::Sumsq => StaticResult::Scalar,
+        Function::N => scalar_arguments(args),
+        Function::Sheets => scalar_arguments(args),
+        Function::Cell => scalar_arguments(args),
+        Function::Info => scalar_arguments(args),
+
+        Function::Dget => not_implemented(args),
+        Function::Dmax => not_implemented(args),
+        Function::Dmin => not_implemented(args),
+        Function::Dcount => not_implemented(args),
+        Function::Daverage => not_implemented(args),
+        Function::Dsum => not_implemented(args),
+        Function::Dcounta => not_implemented(args),
+        Function::Dproduct => not_implemented(args),
+        Function::Dstdev => not_implemented(args),
+        Function::Dvar => not_implemented(args),
+        Function::Dvarp => not_implemented(args),
+        Function::Dstdevp => not_implemented(args),
     }
 }

base/src/expressions/parser/stringify.rs

@@ -2,7 +2,7 @@ use super::{super::utils::quote_name, Node, Reference};
 use crate::constants::{LAST_COLUMN, LAST_ROW};
 use crate::expressions::parser::move_formula::to_string_array_node;
 use crate::expressions::parser::static_analysis::add_implicit_intersection;
-use crate::expressions::token::OpUnary;
+use crate::expressions::token::{OpSum, OpUnary};
 use crate::{expressions::types::CellReferenceRC, number_format::to_excel_precision_str};
 
 pub enum DisplaceData {
@@ -28,6 +28,11 @@ pub enum DisplaceData {
         column: i32,
         delta: i32,
     },
+    RowMove {
+        sheet: u32,
+        row: i32,
+        delta: i32,
+    },
     ColumnMove {
         sheet: u32,
         column: i32,
@@ -159,6 +164,29 @@ pub(crate) fn stringify_reference(
                         }
                     }
                 }
+                DisplaceData::RowMove {
+                    sheet,
+                    row: move_row,
+                    delta,
+                } => {
+                    if sheet_index == *sheet {
+                        if row == *move_row {
+                            row += *delta;
+                        } else if *delta > 0 {
+                            // Moving the row downwards
+                            if row > *move_row && row <= *move_row + *delta {
+                                // Intermediate rows move up by one position
+                                row -= 1;
+                            }
+                        } else if *delta < 0 {
+                            // Moving the row upwards
+                            if row < *move_row && row >= *move_row + *delta {
+                                // Intermediate rows move down by one position
+                                row += 1;
+                            }
+                        }
+                    }
+                }
                 DisplaceData::ColumnMove {
                     sheet,
                     column: move_column,
@@ -167,14 +195,18 @@ pub(crate) fn stringify_reference(
                     if sheet_index == *sheet {
                         if column == *move_column {
                             column += *delta;
-                        } else if (*delta > 0
+                        } else if *delta > 0 {
-                            && column > *move_column
+                            // Moving the column to the right
-                            && column <= *move_column + *delta)
+                            if column > *move_column && column <= *move_column + *delta {
-                            || (*delta < 0
+                                // Intermediate columns move left by one position
-                                && column < *move_column
+                                column -= 1;
-                                && column >= *move_column + *delta)
+                            }
-                        {
+                        } else if *delta < 0 {
-                            column -= *delta;
+                            // Moving the column to the left
+                            if column < *move_column && column >= *move_column + *delta {
+                                // Intermediate columns move right by one position
+                                column += 1;
+                            }
                         }
                     }
                 }
@@ -184,16 +216,16 @@ pub(crate) fn stringify_reference(
                 return "#REF!".to_string();
             }
             let mut row_abs = if absolute_row {
-                format!("${}", row)
+                format!("${row}")
             } else {
-                format!("{}", row)
+                format!("{row}")
             };
             let column = match crate::expressions::utils::number_to_column(column) {
                 Some(s) => s,
                 None => return "#REF!".to_string(),
             };
             let mut col_abs = if absolute_column {
-                format!("${}", column)
+                format!("${column}")
             } else {
                 column
             };
@@ -208,27 +240,27 @@ pub(crate) fn stringify_reference(
                     format!("{}!{}{}", quote_name(name), col_abs, row_abs)
                 }
                 None => {
-                    format!("{}{}", col_abs, row_abs)
+                    format!("{col_abs}{row_abs}")
                 }
             }
         }
         None => {
             let row_abs = if absolute_row {
-                format!("R{}", row)
+                format!("R{row}")
             } else {
-                format!("R[{}]", row)
+                format!("R[{row}]")
             };
             let col_abs = if absolute_column {
-                format!("C{}", column)
+                format!("C{column}")
             } else {
-                format!("C[{}]", column)
+                format!("C[{column}]")
             };
             match &sheet_name {
                 Some(name) => {
                     format!("{}!{}{}", quote_name(name), row_abs, col_abs)
                 }
                 None => {
-                    format!("{}{}", row_abs, col_abs)
+                    format!("{row_abs}{col_abs}")
                 }
             }
         }
@@ -256,7 +288,7 @@ fn format_function(
             arguments = stringify(el, context, displace_data, export_to_excel);
         }
     }
-    format!("{}({})", name, arguments)
+    format!("{name}({arguments})")
 }
 
 // There is just one representation in the AST (Abstract Syntax Tree) of a formula.
@@ -292,9 +324,9 @@ fn stringify(
 ) -> String {
     use self::Node::*;
     match node {
-        BooleanKind(value) => format!("{}", value).to_ascii_uppercase(),
+        BooleanKind(value) => format!("{value}").to_ascii_uppercase(),
         NumberKind(number) => to_excel_precision_str(*number),
-        StringKind(value) => format!("\"{}\"", value),
+        StringKind(value) => format!("\"{value}\""),
         WrongReferenceKind {
             sheet_name,
             column,
@@ -384,7 +416,7 @@ fn stringify(
                 full_row,
                 full_column,
             );
-            format!("{}:{}", s1, s2)
+            format!("{s1}:{s2}")
         }
         WrongRangeKind {
             sheet_name,
@@ -433,7 +465,7 @@ fn stringify(
                 full_row,
                 full_column,
             );
-            format!("{}:{}", s1, s2)
+            format!("{s1}:{s2}")
         }
         OpRangeKind { left, right } => format!(
             "{}:{}",
@@ -451,45 +483,44 @@ fn stringify(
             kind,
             stringify(right, context, displace_data, export_to_excel)
         ),
-        OpSumKind { kind, left, right } => format!(
+        OpSumKind { kind, left, right } => {
-            "{}{}{}",
+            let left_str = stringify(left, context, displace_data, export_to_excel);
-            stringify(left, context, displace_data, export_to_excel),
+            // if kind is minus then we need parentheses in the right side if they are OpSumKind or CompareKind
-            kind,
+            let right_str = if (matches!(kind, OpSum::Minus) && matches!(**right, OpSumKind { .. }))
+                | matches!(**right, CompareKind { .. })
+            {
+                format!(
+                    "({})",
                     stringify(right, context, displace_data, export_to_excel)
-        ),
+                )
+            } else {
+                stringify(right, context, displace_data, export_to_excel)
+            };
+
+            format!("{left_str}{kind}{right_str}")
+        }
         OpProductKind { kind, left, right } => {
             let x = match **left {
-                OpSumKind { .. } => format!(
+                OpSumKind { .. } | CompareKind { .. } => format!(
-                    "({})",
-                    stringify(left, context, displace_data, export_to_excel)
-                ),
-                CompareKind { .. } => format!(
                     "({})",
                     stringify(left, context, displace_data, export_to_excel)
                 ),
                 _ => stringify(left, context, displace_data, export_to_excel),
             };
             let y = match **right {
-                OpSumKind { .. } => format!(
+                OpSumKind { .. } | CompareKind { .. } | OpProductKind { .. } => format!(
-                    "({})",
-                    stringify(right, context, displace_data, export_to_excel)
-                ),
-                CompareKind { .. } => format!(
-                    "({})",
-                    stringify(right, context, displace_data, export_to_excel)
-                ),
-                OpProductKind { .. } => format!(
                     "({})",
                     stringify(right, context, displace_data, export_to_excel)
                 ),
                 _ => stringify(right, context, displace_data, export_to_excel),
             };
-            format!("{}{}{}", x, kind, y)
+            format!("{x}{kind}{y}")
         }
         OpPowerKind { left, right } => {
             let x = match **left {
                 BooleanKind(_)
                 | NumberKind(_)
+                | UnaryKind { .. }
                 | StringKind(_)
                 | ReferenceKind { .. }
                 | RangeKind { .. }
@@ -505,7 +536,6 @@ fn stringify(
                 | FunctionKind { .. }
                 | InvalidFunctionKind { .. }
                 | ArrayKind(_)
-                | UnaryKind { .. }
                 | ErrorKind(_)
                 | ParseErrorKind { .. }
                 | OpSumKind { .. }
@@ -547,7 +577,7 @@ fn stringify(
                     stringify(right, context, displace_data, export_to_excel)
                 ),
             };
-            format!("{}^{}", x, y)
+            format!("{x}^{y}")
         }
         InvalidFunctionKind { name, args } => {
             format_function(name, args, context, displace_data, export_to_excel)
@@ -582,18 +612,50 @@ fn stringify(
                 }
                 matrix_string.push_str(&row_string);
             }
-            format!("{{{}}}", matrix_string)
+            format!("{{{matrix_string}}}")
         }
         TableNameKind(value) => value.to_string(),
         DefinedNameKind((name, ..)) => name.to_string(),
         WrongVariableKind(name) => name.to_string(),
         UnaryKind { kind, right } => match kind {
             OpUnary::Minus => {
+                let needs_parentheses = match **right {
+                    BooleanKind(_)
+                    | NumberKind(_)
+                    | StringKind(_)
+                    | ReferenceKind { .. }
+                    | RangeKind { .. }
+                    | WrongReferenceKind { .. }
+                    | WrongRangeKind { .. }
+                    | OpRangeKind { .. }
+                    | OpConcatenateKind { .. }
+                    | OpProductKind { .. }
+                    | FunctionKind { .. }
+                    | InvalidFunctionKind { .. }
+                    | ArrayKind(_)
+                    | DefinedNameKind(_)
+                    | TableNameKind(_)
+                    | WrongVariableKind(_)
+                    | ImplicitIntersection { .. }
+                    | CompareKind { .. }
+                    | ErrorKind(_)
+                    | ParseErrorKind { .. }
+                    | EmptyArgKind => false,
+
+                    OpPowerKind { .. } | OpSumKind { .. } | UnaryKind { .. } => true,
+                };
+                if needs_parentheses {
+                    format!(
+                        "-({})",
+                        stringify(right, context, displace_data, export_to_excel)
+                    )
+                } else {
                     format!(
                         "-{}",
                         stringify(right, context, displace_data, export_to_excel)
                     )
                 }
+            }
             OpUnary::Percentage => {
                 format!(
                     "{}%",
@@ -601,7 +663,7 @@ fn stringify(
                 )
             }
         },
-        ErrorKind(kind) => format!("{}", kind),
+        ErrorKind(kind) => format!("{kind}"),
         ParseErrorKind {
             formula,
             position: _,

base/src/expressions/parser/tests/mod.rs

@@ -3,6 +3,7 @@ mod test_arrays;
 mod test_general;
 mod test_implicit_intersection;
 mod test_issue_155;
+mod test_issue_483;
 mod test_move_formula;
 mod test_ranges;
 mod test_stringify;

base/src/expressions/parser/tests/test_issue_483.rs

@@ -0,0 +1,27 @@
+#![allow(clippy::panic)]
+
+use std::collections::HashMap;
+
+use crate::expressions::parser::stringify::to_string;
+use crate::expressions::parser::{Node, Parser};
+use crate::expressions::types::CellReferenceRC;
+
+#[test]
+fn issue_483_parser() {
+    let worksheets = vec!["Sheet1".to_string()];
+    let mut parser = Parser::new(worksheets, vec![], HashMap::new());
+
+    // Reference cell is Sheet1!A1
+    let cell_reference = CellReferenceRC {
+        sheet: "Sheet1".to_string(),
+        row: 2,
+        column: 2,
+    };
+    let t = parser.parse("-(A1^1.22)", &cell_reference);
+    assert!(matches!(t, Node::UnaryKind { .. }));
+    assert_eq!(to_string(&t, &cell_reference), "-(A1^1.22)");
+
+    let t = parser.parse("-A1^1.22", &cell_reference);
+    assert!(matches!(t, Node::OpPowerKind { .. }));
+    assert_eq!(to_string(&t, &cell_reference), "-A1^1.22");
+}

base/src/expressions/parser/tests/test_stringify.rs

@@ -32,3 +32,39 @@ fn exp_order() {
     let t = parser.parse("(5)^(4)", &cell_reference);
     assert_eq!(to_string(&t, &cell_reference), "5^4");
 }
+
+#[test]
+fn correct_parenthesis() {
+    let worksheets = vec!["Sheet1".to_string()];
+    let mut parser = Parser::new(worksheets, vec![], HashMap::new());
+
+    let cell_reference = CellReferenceRC {
+        sheet: "Sheet1".to_string(),
+        row: 1,
+        column: 1,
+    };
+
+    let t = parser.parse("-(1 + 1)", &cell_reference);
+    assert_eq!(to_string(&t, &cell_reference), "-(1+1)");
+
+    let t = parser.parse("1 - (3 + 4)", &cell_reference);
+    assert_eq!(to_string(&t, &cell_reference), "1-(3+4)");
+
+    let t = parser.parse("-(1.05*(0.0284 + 0.0046) - 0.0284)", &cell_reference);
+    assert_eq!(
+        to_string(&t, &cell_reference),
+        "-(1.05*(0.0284+0.0046)-0.0284)"
+    );
+
+    let t = parser.parse("1 + (3+5)", &cell_reference);
+    assert_eq!(to_string(&t, &cell_reference), "1+3+5");
+
+    let t = parser.parse("1 - (3+5)", &cell_reference);
+    assert_eq!(to_string(&t, &cell_reference), "1-(3+5)");
+
+    let t = parser.parse("(1 - 3) - (3+5)", &cell_reference);
+    assert_eq!(to_string(&t, &cell_reference), "1-3-(3+5)");
+
+    let t = parser.parse("1 + (3<5)", &cell_reference);
+    assert_eq!(to_string(&t, &cell_reference), "1+(3<5)");
+}

base/src/expressions/utils/mod.rs

@@ -211,15 +211,19 @@ pub fn parse_reference_a1(r: &str) -> Option<ParsedReference> {
 pub fn is_valid_identifier(name: &str) -> bool {
     // https://support.microsoft.com/en-us/office/names-in-formulas-fc2935f9-115d-4bef-a370-3aa8bb4c91f1
     // https://github.com/MartinTrummer/excel-names/
-    // NOTE: We are being much more restrictive than Excel.
-    // In particular we do not support non ascii characters.
     let upper = name.to_ascii_uppercase();
-    let bytes = upper.as_bytes();
+    // length of chars
-    let len = bytes.len();
+    let len = upper.chars().count();
+
+    let mut chars = upper.chars();
+
     if len > 255 || len == 0 {
         return false;
     }
-    let first = bytes[0] as char;
+    let first = match chars.next() {
+        Some(ch) => ch,
+        None => return false,
+    };
     // The first character of a name must be a letter, an underscore character (_), or a backslash (\).
     if !(first.is_ascii_alphabetic() || first == '_' || first == '\\') {
         return false;
@@ -237,21 +241,11 @@ pub fn is_valid_identifier(name: &str) -> bool {
     if parse_reference_r1c1(name).is_some() {
         return false;
     }
-    let mut i = 1;
+    for ch in chars {
-    while i < len {
+        if !(ch.is_alphanumeric() || ch == '_' || ch == '.') {
-        let ch = bytes[i] as char;
-        match ch {
-            'a'..='z' => {}
-            'A'..='Z' => {}
-            '0'..='9' => {}
-            '_' => {}
-            '.' => {}
-            _ => {
             return false;
         }
     }
-        i += 1;
-    }
 
     true
 }
@@ -259,15 +253,23 @@ pub fn is_valid_identifier(name: &str) -> bool {
 fn name_needs_quoting(name: &str) -> bool {
     let chars = name.chars();
     // it contains any of these characters: ()'$,;-+{} or space
-    for char in chars {
+    for (i, char) in chars.enumerate() {
         if [' ', '(', ')', '\'', '$', ',', ';', '-', '+', '{', '}'].contains(&char) {
             return true;
         }
+        // if it starts with a number
+        if i == 0 && char.is_ascii_digit() {
+            return true;
         }
-    // TODO:
+    }
+    if parse_reference_a1(name).is_some() {
         // cell reference in A1 notation, e.g. B1048576 is quoted, B1048577 is not
+        return true;
+    }
+    if parse_reference_r1c1(name).is_some() {
         // cell reference in R1C1 notation, e.g. RC, RC2, R5C, R-4C, RC-8, R, C
-    // integers
+        return true;
+    }
     false
 }
 
@@ -279,3 +281,32 @@ pub fn quote_name(name: &str) -> String {
     };
     name.to_string()
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_quote_name() {
+        assert_eq!(quote_name("Sheet1"), "Sheet1");
+        assert_eq!(quote_name("Sheet 1"), "'Sheet 1'");
+        // escape and quote
+        assert_eq!(quote_name("Sheet1'"), "'Sheet1'''");
+        assert_eq!(quote_name("Data(2024)"), "'Data(2024)'");
+        assert_eq!(quote_name("Data$2024"), "'Data$2024'");
+        assert_eq!(quote_name("Data-2024"), "'Data-2024'");
+        assert_eq!(quote_name("Data+2024"), "'Data+2024'");
+        assert_eq!(quote_name("Data,2024"), "'Data,2024'");
+        assert_eq!(quote_name("Data;2024"), "'Data;2024'");
+        assert_eq!(quote_name("Data{2024}"), "'Data{2024}'");
+
+        assert_eq!(quote_name("2024"), "'2024'");
+        assert_eq!(quote_name("1Data"), "'1Data'");
+        assert_eq!(quote_name("A1"), "'A1'");
+        assert_eq!(quote_name("R1C1"), "'R1C1'");
+        assert_eq!(quote_name("MySheet"), "MySheet");
+
+        assert_eq!(quote_name("B1048576"), "'B1048576'");
+        assert_eq!(quote_name("B1048577"), "B1048577");
+    }
+}

base/src/expressions/utils/test.rs

@@ -196,6 +196,7 @@ fn test_names() {
     assert!(is_valid_identifier("_."));
     assert!(is_valid_identifier("_1"));
     assert!(is_valid_identifier("\\."));
+    assert!(is_valid_identifier("truñe"));
 
     // invalid
     assert!(!is_valid_identifier("true"));
@@ -209,6 +210,7 @@ fn test_names() {
     assert!(!is_valid_identifier("1true"));
 
     assert!(!is_valid_identifier("test€"));
-    assert!(!is_valid_identifier("truñe"));
     assert!(!is_valid_identifier("tr&ue"));
+
+    assert!(!is_valid_identifier("LOG10"));
 }

base/src/formatter/dates.rs

@@ -8,6 +8,8 @@ use crate::constants::EXCEL_DATE_BASE;
 use crate::constants::MAXIMUM_DATE_SERIAL_NUMBER;
 use crate::constants::MINIMUM_DATE_SERIAL_NUMBER;
 
+pub const DATE_OUT_OF_RANGE_MESSAGE: &str = "Out of range parameters for date";
+
 #[inline]
 fn convert_to_serial_number(date: NaiveDate) -> i32 {
     date.num_days_from_ce() - EXCEL_DATE_BASE
@@ -21,14 +23,12 @@ fn is_date_within_range(date: NaiveDate) -> bool {
 pub fn from_excel_date(days: i64) -> Result<NaiveDate, String> {
     if days < MINIMUM_DATE_SERIAL_NUMBER as i64 {
         return Err(format!(
-            "Excel date must be greater than {}",
+            "Excel date must be greater than {MINIMUM_DATE_SERIAL_NUMBER}"
-            MINIMUM_DATE_SERIAL_NUMBER
         ));
     };
     if days > MAXIMUM_DATE_SERIAL_NUMBER as i64 {
         return Err(format!(
-            "Excel date must be less than {}",
+            "Excel date must be less than {MAXIMUM_DATE_SERIAL_NUMBER}"
-            MAXIMUM_DATE_SERIAL_NUMBER
         ));
     };
     #[allow(clippy::expect_used)]
@@ -39,7 +39,7 @@ pub fn from_excel_date(days: i64) -> Result<NaiveDate, String> {
 pub fn date_to_serial_number(day: u32, month: u32, year: i32) -> Result<i32, String> {
     match NaiveDate::from_ymd_opt(year, month, day) {
         Some(native_date) => Ok(convert_to_serial_number(native_date)),
-        None => Err("Out of range parameters for date".to_string()),
+        None => Err(DATE_OUT_OF_RANGE_MESSAGE.to_string()),
     }
 }
 
@@ -57,7 +57,7 @@ pub fn permissive_date_to_serial_number(day: i32, month: i32, year: i32) -> Resu
         return Ok(MINIMUM_DATE_SERIAL_NUMBER);
     }
     let Some(mut date) = NaiveDate::from_ymd_opt(year, 1, 1) else {
-        return Err("Out of range parameters for date".to_string());
+        return Err(DATE_OUT_OF_RANGE_MESSAGE.to_string());
     };
 
     // One thing to note for example is that even if you started with a year out of range
@@ -70,7 +70,7 @@ pub fn permissive_date_to_serial_number(day: i32, month: i32, year: i32) -> Resu
     // As a result, we have to run range checks as we parse the date from the biggest unit to the
     // smallest unit.
     if !is_date_within_range(date) {
-        return Err("Out of range parameters for date".to_string());
+        return Err(DATE_OUT_OF_RANGE_MESSAGE.to_string());
     }
 
     date = {
@@ -82,7 +82,7 @@ pub fn permissive_date_to_serial_number(day: i32, month: i32, year: i32) -> Resu
             date = date + Months::new(abs_month);
         }
         if !is_date_within_range(date) {
-            return Err("Out of range parameters for date".to_string());
+            return Err(DATE_OUT_OF_RANGE_MESSAGE.to_string());
         }
         date
     };
@@ -96,7 +96,7 @@ pub fn permissive_date_to_serial_number(day: i32, month: i32, year: i32) -> Resu
             date = date + Days::new(abs_day);
         }
         if !is_date_within_range(date) {
-            return Err("Out of range parameters for date".to_string());
+            return Err(DATE_OUT_OF_RANGE_MESSAGE.to_string());
         }
         date
     };

base/src/formatter/format.rs

@@ -15,7 +15,7 @@ pub struct Formatted {
 
 /// Returns the vector of chars of the fractional part of a *positive* number:
 /// 3.1415926 ==> ['1', '4', '1', '5', '9', '2', '6']
-fn get_fract_part(value: f64, precision: i32) -> Vec<char> {
+fn get_fract_part(value: f64, precision: i32, int_len: usize) -> Vec<char> {
     let b = format!("{:.1$}", value.fract(), precision as usize)
         .chars()
         .collect::<Vec<char>>();
@@ -30,6 +30,12 @@ fn get_fract_part(value: f64, precision: i32) -> Vec<char> {
     if last_non_zero < 2 {
         return vec![];
     }
+    let max_len = if int_len > 15 {
+        2_usize
+    } else {
+        15_usize - int_len + 1
+    };
+    let last_non_zero = usize::min(last_non_zero, max_len + 1);
     b[2..last_non_zero].to_vec()
 }
 
@@ -120,7 +126,7 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
             // We should have different codepaths for general formatting and errors
             let value_abs = value.abs();
             if (1.0e-8..1.0e+11).contains(&value_abs) {
-                let mut text = format!("{:.9}", value);
+                let mut text = format!("{value:.9}");
                 text = text.trim_end_matches('0').trim_end_matches('.').to_string();
                 Formatted {
                     text,
@@ -138,7 +144,7 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
                 let exponent = value_abs.log10().floor();
                 value /= 10.0_f64.powf(exponent);
                 let sign = if exponent < 0.0 { '-' } else { '+' };
-                let s = format!("{:.5}", value);
+                let s = format!("{value:.5}");
                 Formatted {
                     text: format!(
                         "{}E{}{:02}",
@@ -154,48 +160,72 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
         ParsePart::Date(p) => {
             let tokens = &p.tokens;
             let mut text = "".to_string();
-            let date = match from_excel_date(value as i64) {
+            let time_fract = value.fract();
-                Ok(d) => d,
+            let hours = (time_fract * 24.0).floor();
-                Err(e) => {
+            let minutes = ((time_fract * 24.0 - hours) * 60.0).floor();
-                    return Formatted {
+            let seconds = ((((time_fract * 24.0 - hours) * 60.0) - minutes) * 60.0).round();
-                        text: "#VALUE!".to_owned(),
+            let date = from_excel_date(value as i64).ok();
-                        color: None,
-                        error: Some(e),
-                    }
-                }
-            };
             for token in tokens {
                 match token {
                     TextToken::Literal(c) => {
-                        text = format!("{}{}", text, c);
+                        text = format!("{text}{c}");
                     }
                     TextToken::Text(t) => {
-                        text = format!("{}{}", text, t);
+                        text = format!("{text}{t}");
                     }
                     TextToken::Ghost(_) => {
                         // we just leave a whitespace
                         // This is what the TEXT function does
-                        text = format!("{} ", text);
+                        text = format!("{text} ");
                     }
                     TextToken::Spacer(_) => {
                         // we just leave a whitespace
                         // This is what the TEXT function does
-                        text = format!("{} ", text);
+                        text = format!("{text} ");
                     }
                     TextToken::Raw => {
-                        text = format!("{}{}", text, value);
+                        text = format!("{text}{value}");
                     }
                     TextToken::Digit(_) => {}
                     TextToken::Period => {}
-                    TextToken::Day => {
+                    TextToken::Day => match date {
+                        Some(date) => {
                             let day = date.day() as usize;
-                        text = format!("{}{}", text, day);
+                            text = format!("{text}{day}");
                         }
+                        None => {
+                            return Formatted {
+                                text: "#VALUE!".to_owned(),
+                                color: None,
+                                error: Some(format!("Invalid date value: '{value}'")),
+                            }
+                        }
+                    },
                     TextToken::DayPadded => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let day = date.day() as usize;
-                        text = format!("{}{:02}", text, day);
+                        text = format!("{text}{day:02}");
                     }
                     TextToken::DayNameShort => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let mut day = date.weekday().number_from_monday() as usize;
                         if day == 7 {
                             day = 0;
@@ -203,6 +233,16 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
                         text = format!("{}{}", text, &locale.dates.day_names_short[day]);
                     }
                     TextToken::DayName => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let mut day = date.weekday().number_from_monday() as usize;
                         if day == 7 {
                             day = 0;
@@ -210,32 +250,144 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
                         text = format!("{}{}", text, &locale.dates.day_names[day]);
                     }
                     TextToken::Month => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let month = date.month() as usize;
-                        text = format!("{}{}", text, month);
+                        text = format!("{text}{month}");
                     }
                     TextToken::MonthPadded => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let month = date.month() as usize;
-                        text = format!("{}{:02}", text, month);
+                        text = format!("{text}{month:02}");
                     }
                     TextToken::MonthNameShort => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let month = date.month() as usize;
                         text = format!("{}{}", text, &locale.dates.months_short[month - 1]);
                     }
                     TextToken::MonthName => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let month = date.month() as usize;
                         text = format!("{}{}", text, &locale.dates.months[month - 1]);
                     }
                     TextToken::MonthLetter => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         let month = date.month() as usize;
                         let months_letter = &locale.dates.months_letter[month - 1];
-                        text = format!("{}{}", text, months_letter);
+                        text = format!("{text}{months_letter}");
                     }
                     TextToken::YearShort => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         text = format!("{}{}", text, date.format("%y"));
                     }
                     TextToken::Year => {
+                        let date = match date {
+                            Some(d) => d,
+                            None => {
+                                return Formatted {
+                                    text: "#VALUE!".to_owned(),
+                                    color: None,
+                                    error: Some(format!("Invalid date value: '{value}'")),
+                                }
+                            }
+                        };
                         text = format!("{}{}", text, date.year());
                     }
+                    TextToken::Hour => {
+                        let mut hour = hours as i32;
+                        if p.use_ampm {
+                            if hour == 0 {
+                                hour = 12;
+                            } else if hour > 12 {
+                                hour -= 12;
+                            }
+                        }
+                        text = format!("{text}{hour}");
+                    }
+                    TextToken::HourPadded => {
+                        let mut hour = hours as i32;
+                        if p.use_ampm {
+                            if hour == 0 {
+                                hour = 12;
+                            } else if hour > 12 {
+                                hour -= 12;
+                            }
+                        }
+                        text = format!("{text}{hour:02}");
+                    }
+                    TextToken::Second => {
+                        let second = seconds as i32;
+                        text = format!("{text}{second}");
+                    }
+                    TextToken::SecondPadded => {
+                        let second = seconds as i32;
+                        text = format!("{text}{second:02}");
+                    }
+                    TextToken::AMPM => {
+                        let ampm = if hours < 12.0 { "AM" } else { "PM" };
+                        text = format!("{text}{ampm}");
+                    }
+                    TextToken::Minute => {
+                        let minute = minutes as i32;
+                        text = format!("{text}{minute}");
+                    }
+                    TextToken::MinutePadded => {
+                        let minute = minutes as i32;
+                        text = format!("{text}{minute:02}");
+                    }
                 }
             }
             Formatted {
@@ -247,7 +399,7 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
         ParsePart::Number(p) => {
             let mut text = "".to_string();
             if let Some(c) = p.currency {
-                text = format!("{}", c);
+                text = format!("{c}");
             }
             let tokens = &p.tokens;
             value = value * 100.0_f64.powi(p.percent) / (1000.0_f64.powi(p.comma));
@@ -277,7 +429,7 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
             if value_abs as i64 == 0 {
                 int_part = vec![];
             }
-            let fract_part = get_fract_part(value_abs, p.precision);
+            let fract_part = get_fract_part(value_abs, p.precision, int_part.len());
             // ln is the number of digits of the integer part of the value
             let ln = int_part.len() as i32;
             // digit count is the number of digit tokens ('0', '?' and '#') to the left of the decimal point
@@ -295,26 +447,26 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
             for token in tokens {
                 match token {
                     TextToken::Literal(c) => {
-                        text = format!("{}{}", text, c);
+                        text = format!("{text}{c}");
                     }
                     TextToken::Text(t) => {
-                        text = format!("{}{}", text, t);
+                        text = format!("{text}{t}");
                     }
                     TextToken::Ghost(_) => {
                         // we just leave a whitespace
                         // This is what the TEXT function does
-                        text = format!("{} ", text);
+                        text = format!("{text} ");
                     }
                     TextToken::Spacer(_) => {
                         // we just leave a whitespace
                         // This is what the TEXT function does
-                        text = format!("{} ", text);
+                        text = format!("{text} ");
                     }
                     TextToken::Raw => {
-                        text = format!("{}{}", text, value);
+                        text = format!("{text}{value}");
                     }
                     TextToken::Period => {
-                        text = format!("{}{}", text, decimal_separator);
+                        text = format!("{text}{decimal_separator}");
                     }
                     TextToken::Digit(digit) => {
                         if digit.number == 'i' {
@@ -322,7 +474,7 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
                             let index = digit.index;
                             let number_index = ln - digit_count + index;
                             if index == 0 && is_negative {
-                                text = format!("-{}", text);
+                                text = format!("-{text}");
                             }
                             if ln <= digit_count {
                                 // The number of digits is less or equal than the number of digit tokens
@@ -347,7 +499,7 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
                                     } else {
                                         ""
                                     };
-                                    text = format!("{}{}{}", text, c, sep);
+                                    text = format!("{text}{c}{sep}");
                                 }
                                 digit_index += 1;
                             } else {
@@ -373,18 +525,18 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
                             if index < fract_part.len() {
                                 text = format!("{}{}", text, fract_part[index]);
                             } else if digit.kind == '0' {
-                                text = format!("{}0", text);
+                                text = format!("{text}0");
                             } else if digit.kind == '?' {
-                                text = format!("{} ", text);
+                                text = format!("{text} ");
                             }
                         } else if digit.number == 'e' {
                             // 3. Exponent part
                             let index = digit.index;
                             if index == 0 {
                                 if exponent_is_negative {
-                                    text = format!("{}E-", text);
+                                    text = format!("{text}E-");
                                 } else {
-                                    text = format!("{}E+", text);
+                                    text = format!("{text}E+");
                                 }
                             }
                             let number_index = l_exp - (p.exponent_digit_count - index);
@@ -400,7 +552,7 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
                                         exponent_part[number_index as usize]
                                     };
 
-                                    text = format!("{}{}", text, c);
+                                    text = format!("{text}{c}");
                                 }
                             } else {
                                 for i in 0..number_index + 1 {
@@ -422,6 +574,13 @@ pub fn format_number(value_original: f64, format: &str, locale: &Locale) -> Form
                     TextToken::MonthLetter => {}
                     TextToken::YearShort => {}
                     TextToken::Year => {}
+                    TextToken::Hour => {}
+                    TextToken::HourPadded => {}
+                    TextToken::Minute => {}
+                    TextToken::MinutePadded => {}
+                    TextToken::Second => {}
+                    TextToken::SecondPadded => {}
+                    TextToken::AMPM => {}
                 }
             }
             Formatted {
@@ -591,10 +750,10 @@ fn parse_date(value: &str) -> Result<(i32, String), String> {
 /// "30.34%" => (0.3034, "0.00%")
 /// 100€ => (100, "100€")
 pub(crate) fn parse_formatted_number(
-    value: &str,
+    original: &str,
     currencies: &[&str],
 ) -> Result<(f64, Option<String>), String> {
-    let value = value.trim();
+    let value = original.trim();
     let scientific_format = "0.00E+00";
 
     // Check if it is a percentage
@@ -614,7 +773,7 @@ pub(crate) fn parse_formatted_number(
 
     // check if it is a currency in currencies
     for currency in currencies {
-        if let Some(p) = value.strip_prefix(&format!("-{}", currency)) {
+        if let Some(p) = value.strip_prefix(&format!("-{currency}")) {
             let (f, options) = parse_number(p.trim())?;
             if options.is_scientific {
                 return Ok((f, Some(scientific_format.to_string())));
@@ -646,7 +805,8 @@ pub(crate) fn parse_formatted_number(
         }
     }
 
-    if let Ok((serial_number, format)) = parse_date(value) {
+    // check if it is a date. NOTE: we don't trim the original here
+    if let Ok((serial_number, format)) = parse_date(original) {
         return Ok((serial_number as f64, Some(format)));
     }
 

base/src/formatter/lexer.rs

@@ -26,19 +26,23 @@ pub enum Token {
     Scientific,    // E+
     ScientificMinus, // E-
     General,       // General
-    // Dates
+    // Dates and time
     Day,            // d
     DayPadded,      // dd
     DayNameShort,   // ddd
     DayName,        // dddd+
-    Month,          // m
+    Month,          // m (or minute)
-    MonthPadded,    // mm
+    MonthPadded,    // mm (or minute padded)
     MonthNameShort, // mmm
     MonthName,      // mmmm or mmmmmm+
     MonthLetter,    // mmmmm
     YearShort,      // y or yy
     Year,           // yyy+
-    // TODO: Hours Minutes and Seconds
+    Hour,           // h
+    HourPadded,     // hh
+    Second,         // s
+    SecondPadded,   // ss
+    AMPM,           // AM/PM (or A/P)
     ILLEGAL,
     EOF,
 }
@@ -333,7 +337,7 @@ impl Lexer {
                         } else if s == '-' {
                             Token::ScientificMinus
                         } else {
-                            self.set_error(&format!("Unexpected char: {}. Expected + or -", s));
+                            self.set_error(&format!("Unexpected char: {s}. Expected + or -"));
                             Token::ILLEGAL
                         }
                     } else {
@@ -361,8 +365,8 @@ impl Lexer {
                         self.read_next_char();
                     }
                     match m {
-                        1 => Token::Month,
+                        1 => Token::Month,       // (or minute)
-                        2 => Token::MonthPadded,
+                        2 => Token::MonthPadded, // (or minute padded)
                         3 => Token::MonthNameShort,
                         4 => Token::MonthName,
                         5 => Token::MonthLetter,
@@ -381,18 +385,75 @@ impl Lexer {
                         Token::Year
                     }
                 }
+                'h' => {
+                    let mut h = 1;
+                    while let Some('h') = self.peek_char() {
+                        h += 1;
+                        self.read_next_char();
+                    }
+                    if h == 1 {
+                        Token::Hour
+                    } else if h == 2 {
+                        Token::HourPadded
+                    } else {
+                        self.set_error("Unexpected character after 'h'");
+                        Token::ILLEGAL
+                    }
+                }
+                's' => {
+                    let mut s = 1;
+                    while let Some('s') = self.peek_char() {
+                        s += 1;
+                        self.read_next_char();
+                    }
+                    if s == 1 {
+                        Token::Second
+                    } else if s == 2 {
+                        Token::SecondPadded
+                    } else {
+                        self.set_error("Unexpected character after 's'");
+                        Token::ILLEGAL
+                    }
+                }
+                'A' | 'a' => {
+                    if let Some('M') | Some('m') = self.peek_char() {
+                        self.read_next_char();
+                    } else {
+                        self.set_error("Unexpected character after 'A'");
+                        return Token::ILLEGAL;
+                    }
+                    if let Some('/') = self.peek_char() {
+                        self.read_next_char();
+                    } else {
+                        self.set_error("Unexpected character after 'AM'");
+                        return Token::ILLEGAL;
+                    }
+                    if let Some('P') | Some('p') = self.peek_char() {
+                        self.read_next_char();
+                    } else {
+                        self.set_error("Unexpected character after 'AM'");
+                        return Token::ILLEGAL;
+                    }
+                    if let Some('M') | Some('m') = self.peek_char() {
+                        self.read_next_char();
+                    } else {
+                        self.set_error("Unexpected character after 'AMP'");
+                        return Token::ILLEGAL;
+                    }
+                    Token::AMPM
+                }
                 'g' | 'G' => {
                     for c in "eneral".chars() {
                         let cc = self.read_next_char();
                         if Some(c) != cc {
-                            self.set_error(&format!("Unexpected character: {}", x));
+                            self.set_error(&format!("Unexpected character: {x}"));
                             return Token::ILLEGAL;
                         }
                     }
                     Token::General
                 }
                 _ => {
-                    self.set_error(&format!("Unexpected character: {}", x));
+                    self.set_error(&format!("Unexpected character: {x}"));
                     Token::ILLEGAL
                 }
             },

base/src/formatter/parser.rs

@@ -27,6 +27,13 @@ pub enum TextToken {
     MonthLetter,
     YearShort,
     Year,
+    Hour,
+    HourPadded,
+    Minute,
+    MinutePadded,
+    Second,
+    SecondPadded,
+    AMPM,
 }
 pub struct NumberPart {
     pub color: Option<i32>,
@@ -45,6 +52,7 @@ pub struct NumberPart {
 
 pub struct DatePart {
     pub color: Option<i32>,
+    pub use_ampm: bool,
     pub tokens: Vec<TextToken>,
 }
 
@@ -101,6 +109,7 @@ impl Parser {
         let mut digit_count = 0;
         let mut precision = 0;
         let mut is_date = false;
+        let mut use_ampm = false;
         let mut is_number = false;
         let mut found_decimal_dot = false;
         let mut use_thousands = false;
@@ -116,6 +125,7 @@ impl Parser {
         let mut number = 'i';
         let mut index = 0;
         let mut currency = None;
+        let mut is_time = false;
 
         while token != Token::EOF && token != Token::Separator {
             let next_token = self.lexer.next_token();
@@ -200,6 +210,9 @@ impl Parser {
                     index += 1;
                 }
                 Token::Literal(value) => {
+                    if value == ':' {
+                        is_time = true;
+                    }
                     tokens.push(TextToken::Literal(value));
                 }
                 Token::Text(value) => {
@@ -236,13 +249,23 @@ impl Parser {
                     tokens.push(TextToken::MonthName);
                 }
                 Token::Month => {
+                    if is_time {
+                        // minute
+                        tokens.push(TextToken::Minute);
+                    } else {
                         is_date = true;
                         tokens.push(TextToken::Month);
                     }
+                }
                 Token::MonthPadded => {
+                    if is_time {
+                        // minute padded
+                        tokens.push(TextToken::MinutePadded);
+                    } else {
                         is_date = true;
                         tokens.push(TextToken::MonthPadded);
                     }
+                }
                 Token::MonthLetter => {
                     is_date = true;
                     tokens.push(TextToken::MonthLetter);
@@ -255,6 +278,32 @@ impl Parser {
                     is_date = true;
                     tokens.push(TextToken::Year);
                 }
+                Token::Hour => {
+                    is_date = true;
+                    is_time = true;
+                    tokens.push(TextToken::Hour);
+                }
+                Token::HourPadded => {
+                    is_date = true;
+                    is_time = true;
+                    tokens.push(TextToken::HourPadded);
+                }
+                Token::Second => {
+                    is_date = true;
+                    is_time = true;
+                    tokens.push(TextToken::Second);
+                }
+                Token::SecondPadded => {
+                    is_date = true;
+                    is_time = true;
+                    tokens.push(TextToken::SecondPadded);
+                }
+
+                Token::AMPM => {
+                    is_date = true;
+                    use_ampm = true;
+                    tokens.push(TextToken::AMPM);
+                }
                 Token::Scientific => {
                     if !is_scientific {
                         index = 0;
@@ -282,7 +331,11 @@ impl Parser {
             if is_number {
                 return ParsePart::Error(ErrorPart {});
             }
-            ParsePart::Date(DatePart { color, tokens })
+            ParsePart::Date(DatePart {
+                color,
+                use_ampm,
+                tokens,
+            })
         } else {
             ParsePart::Number(NumberPart {
                 color,

base/src/formatter/test/mod.rs

@@ -1,2 +1,3 @@
 mod test_general;
 mod test_parse_formatted_number;
+mod test_time;

base/src/formatter/test/test_time.rs

@@ -0,0 +1,32 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::{
+    formatter::format::format_number,
+    locale::{get_locale, Locale},
+};
+
+fn get_default_locale() -> &'static Locale {
+    get_locale("en").unwrap()
+}
+
+#[test]
+fn simple_test() {
+    let locale = get_default_locale();
+    let format = "h:mm AM/PM";
+    let value = 16.001_423_611_111_11; // =1/86400 => 12:02 AM
+    let formatted = format_number(value, format, locale);
+    assert_eq!(formatted.text, "12:02 AM");
+}
+
+#[test]
+fn padded_vs_unpadded() {
+    let locale = get_default_locale();
+    let padded_format = "hh:mm:ss AM/PM";
+    let unpadded_format = "h:m:s AM/PM";
+    let value = 0.25351851851851853; // => 6:05:04 AM (21904/(24*60*60)) where 21904 = 6 * 3600 + 5*60 + 4
+    let formatted = format_number(value, padded_format, locale);
+    assert_eq!(formatted.text, "06:05:04 AM");
+
+    let formatted = format_number(value, unpadded_format, locale);
+    assert_eq!(formatted.text, "6:5:4 AM");
+}

base/src/functions/database.rs

@@ -0,0 +1,946 @@
+use chrono::Datelike;
+
+use crate::{
+    calc_result::CalcResult,
+    expressions::{parser::Node, token::Error, types::CellReferenceIndex},
+    formatter::dates::date_to_serial_number,
+    Model,
+};
+
+use super::util::{compare_values, from_wildcard_to_regex, result_matches_regex};
+
+impl Model {
+    // =DAVERAGE(database, field, criteria)
+    pub(crate) fn fn_daverage(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut sum = 0.0f64;
+        let mut count = 0usize;
+
+        let mut row = db_left.row + 1; // skip header
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if let CalcResult::Number(n) = v {
+                    if n.is_finite() {
+                        sum += n;
+                        count += 1;
+                    }
+                }
+            }
+            row += 1;
+        }
+
+        if count == 0 {
+            return CalcResult::Error {
+                error: Error::DIV,
+                origin: cell,
+                message: "No numeric values matched criteria".to_string(),
+            };
+        }
+
+        CalcResult::Number(sum / count as f64)
+    }
+
+    // =DCOUNT(database, field, criteria)
+    // Counts numeric entries in the field for rows that match criteria
+    pub(crate) fn fn_dcount(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut count = 0usize;
+        let mut row = db_left.row + 1; // skip header
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if matches!(v, CalcResult::Number(_)) {
+                    count += 1;
+                }
+            }
+            row += 1;
+        }
+
+        CalcResult::Number(count as f64)
+    }
+
+    // =DGET(database, field, criteria)
+    // Returns the (single) field value for the unique matching row
+    pub(crate) fn fn_dget(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut result: Option<CalcResult> = None;
+        let mut matches = 0usize;
+
+        let mut row = db_left.row + 1;
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                matches += 1;
+                if matches > 1 {
+                    return CalcResult::Error {
+                        error: Error::NUM,
+                        origin: cell,
+                        message: "More than one matching record".to_string(),
+                    };
+                }
+                result = Some(self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                }));
+            }
+            row += 1;
+        }
+
+        match (matches, result) {
+            (0, _) | (_, None) => CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No matching record".to_string(),
+            },
+            (_, Some(v)) => v,
+        }
+    }
+
+    // =DMAX(database, field, criteria)
+    pub(crate) fn fn_dmax(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        self.db_extreme(args, cell, true)
+    }
+
+    // =DMIN(database, field, criteria)
+    pub(crate) fn fn_dmin(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        self.db_extreme(args, cell, false)
+    }
+
+    // =DSUM(database, field, criteria)
+    pub(crate) fn fn_dsum(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut sum = 0.0;
+
+        // skip header
+        let mut row = db_left.row + 1;
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if let CalcResult::Number(n) = v {
+                    if n.is_finite() {
+                        sum += n;
+                    }
+                }
+            }
+            row += 1;
+        }
+
+        CalcResult::Number(sum)
+    }
+
+    // =DCOUNTA(database, field, criteria)
+    // Counts non-empty entries (any type) in the field for rows that match criteria
+    pub(crate) fn fn_dcounta(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut count = 0;
+        for row in (db_left.row + 1)..=db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if !matches!(v, CalcResult::EmptyCell | CalcResult::EmptyArg) {
+                    count += 1;
+                }
+            }
+        }
+
+        CalcResult::Number(count as f64)
+    }
+
+    // =DPRODUCT(database, field, criteria)
+    pub(crate) fn fn_dproduct(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut product = 1.0f64;
+        let mut has_numeric = false;
+
+        let mut row = db_left.row + 1; // skip header
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if let CalcResult::Number(n) = v {
+                    if n.is_finite() {
+                        product *= n;
+                        has_numeric = true;
+                    }
+                }
+            }
+            row += 1;
+        }
+
+        // Excel returns 0 when no rows / no numeric values match for DPRODUCT
+        if has_numeric {
+            CalcResult::Number(product)
+        } else {
+            CalcResult::Number(0.0)
+        }
+    }
+
+    // Small internal helper for DSTDEV / DVAR
+    // Collects sum, sum of squares, and count of numeric values in the field
+    // for rows that match the criteria.
+    fn db_numeric_stats(
+        &mut self,
+        args: &[Node],
+        cell: CellReferenceIndex,
+    ) -> Result<(f64, f64, usize), CalcResult> {
+        if args.len() != 3 {
+            return Err(CalcResult::new_args_number_error(cell));
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return Err(e),
+        };
+
+        let field_col = self.resolve_db_field_column(db_left, db_right, &args[1], cell)?;
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return Err(e),
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return Err(CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            });
+        }
+
+        let mut sum = 0.0f64;
+        let mut sumsq = 0.0f64;
+        let mut count = 0usize;
+
+        let mut row = db_left.row + 1; // skip header
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if let CalcResult::Number(n) = v {
+                    if n.is_finite() {
+                        sum += n;
+                        sumsq += n * n;
+                        count += 1;
+                    }
+                }
+            }
+            row += 1;
+        }
+
+        Ok((sum, sumsq, count))
+    }
+
+    // =DSTDEV(database, field, criteria)
+    // Sample standard deviation of matching numeric values
+    pub(crate) fn fn_dstdev(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let (sum, sumsq, count) = match self.db_numeric_stats(args, cell) {
+            Ok(stats) => stats,
+            Err(e) => return e,
+        };
+
+        // Excel behaviour: #DIV/0! if 0 or 1 numeric values match
+        if count < 2 {
+            return CalcResult::Error {
+                error: Error::DIV,
+                origin: cell,
+                message: "Not enough numeric values matched criteria".to_string(),
+            };
+        }
+
+        let n = count as f64;
+        let var = (sumsq - (sum * sum) / n) / (n - 1.0);
+        let var = if var < 0.0 { 0.0 } else { var };
+        CalcResult::Number(var.sqrt())
+    }
+
+    // =DVAR(database, field, criteria)
+    // Sample variance of matching numeric values
+    pub(crate) fn fn_dvar(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let (sum, sumsq, count) = match self.db_numeric_stats(args, cell) {
+            Ok(stats) => stats,
+            Err(e) => return e,
+        };
+
+        // Excel behaviour: #DIV/0! if 0 or 1 numeric values match
+        if count < 2 {
+            return CalcResult::Error {
+                error: Error::DIV,
+                origin: cell,
+                message: "Not enough numeric values matched criteria".to_string(),
+            };
+        }
+
+        let n = count as f64;
+        let var = (sumsq - (sum * sum) / n) / (n - 1.0);
+        let var = if var < 0.0 { 0.0 } else { var };
+        CalcResult::Number(var)
+    }
+
+    // =DSTDEVP(database, field, criteria)
+    // Population standard deviation of matching numeric values
+    pub(crate) fn fn_dstdevp(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let (sum, sumsq, count) = match self.db_numeric_stats(args, cell) {
+            Ok(stats) => stats,
+            Err(e) => return e,
+        };
+
+        // Excel behaviour: #DIV/0! if no numeric values match
+        if count == 0 {
+            return CalcResult::Error {
+                error: Error::DIV,
+                origin: cell,
+                message: "No numeric values matched criteria".to_string(),
+            };
+        }
+
+        let n = count as f64;
+        let var = (sumsq - (sum * sum) / n) / n;
+        let var = if var < 0.0 { 0.0 } else { var };
+        CalcResult::Number(var.sqrt())
+    }
+
+    // =DVARP(database, field, criteria)
+    // Population variance of matching numeric values
+    pub(crate) fn fn_dvarp(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let (sum, sumsq, count) = match self.db_numeric_stats(args, cell) {
+            Ok(stats) => stats,
+            Err(e) => return e,
+        };
+
+        // Excel behaviour: #DIV/0! if no numeric values match
+        if count == 0 {
+            return CalcResult::Error {
+                error: Error::DIV,
+                origin: cell,
+                message: "No numeric values matched criteria".to_string(),
+            };
+        }
+
+        let n = count as f64;
+        let var = (sumsq - (sum * sum) / n) / n;
+        let var = if var < 0.0 { 0.0 } else { var };
+        CalcResult::Number(var)
+    }
+
+    /// Resolve the "field" (2nd arg) to an absolute column index (i32) within the sheet.
+    /// Field can be a number (1-based index) or a header name (case-insensitive).
+    /// Returns the absolute column index, not a 1-based offset within the database range.
+    fn resolve_db_field_column(
+        &mut self,
+        db_left: CellReferenceIndex,
+        db_right: CellReferenceIndex,
+        field_arg: &Node,
+        cell: CellReferenceIndex,
+    ) -> Result<i32, CalcResult> {
+        let field_column_name = match self.evaluate_node_in_context(field_arg, cell) {
+            CalcResult::String(s) => s.to_lowercase(),
+            CalcResult::Number(index) => {
+                let index = index.floor() as i32;
+                if index < 1 || db_left.column + index - 1 > db_right.column {
+                    return Err(CalcResult::Error {
+                        error: Error::VALUE,
+                        origin: cell,
+                        message: "Field index out of range".to_string(),
+                    });
+                }
+                return Ok(db_left.column + index - 1);
+            }
+            CalcResult::Boolean(b) => {
+                return if b {
+                    Ok(db_left.column)
+                } else {
+                    // Index 0 is out of range
+                    Err(CalcResult::Error {
+                        error: Error::VALUE,
+                        origin: cell,
+                        message: "Invalid field specifier".to_string(),
+                    })
+                };
+            }
+            error @ CalcResult::Error { .. } => {
+                return Err(error);
+            }
+            CalcResult::Range { .. } => {
+                return Err(CalcResult::Error {
+                    error: Error::NIMPL,
+                    origin: cell,
+                    message: "Arrays not supported yet".to_string(),
+                })
+            }
+            CalcResult::EmptyCell | CalcResult::EmptyArg => "".to_string(),
+            CalcResult::Array(_) => {
+                return Err(CalcResult::Error {
+                    error: Error::NIMPL,
+                    origin: cell,
+                    message: "Arrays not supported yet".to_string(),
+                })
+            }
+        };
+
+        // We search in the database a column whose header matches field_column_name
+        for column in db_left.column..=db_right.column {
+            let v = self.evaluate_cell(CellReferenceIndex {
+                sheet: db_left.sheet,
+                row: db_left.row,
+                column,
+            });
+            match &v {
+                CalcResult::String(s) => {
+                    if s.to_lowercase() == field_column_name {
+                        return Ok(column);
+                    }
+                }
+                CalcResult::Number(n) => {
+                    if field_column_name == n.to_string() {
+                        return Ok(column);
+                    }
+                }
+                CalcResult::Boolean(b) => {
+                    if field_column_name == b.to_string() {
+                        return Ok(column);
+                    }
+                }
+                CalcResult::Error { .. }
+                | CalcResult::Range { .. }
+                | CalcResult::EmptyCell
+                | CalcResult::EmptyArg
+                | CalcResult::Array(_) => {}
+            }
+        }
+
+        Err(CalcResult::Error {
+            error: Error::VALUE,
+            origin: cell,
+            message: "Field header not found".to_string(),
+        })
+    }
+
+    /// Check whether a database row matches the criteria range.
+    /// Criteria logic: OR across criteria rows; AND across columns within a row.
+    fn db_row_matches_criteria(
+        &mut self,
+        db_left: CellReferenceIndex,
+        db_right: CellReferenceIndex,
+        row: i32,
+        criteria: (CellReferenceIndex, CellReferenceIndex),
+    ) -> bool {
+        let (c_left, c_right) = criteria;
+
+        // Read criteria headers (first row of criteria range)
+        // Map header name (lowercased) -> db column (if exists)
+        let mut crit_cols: Vec<i32> = Vec::new();
+        let mut header_count = 0;
+        // We cover the criteria table:
+        //  headerA | headerB | ...
+        //  critA1  | critA2  | ...
+        //  critB1  | critB2  | ...
+        //  ...
+        for column in c_left.column..=c_right.column {
+            let cell = CellReferenceIndex {
+                sheet: c_left.sheet,
+                row: c_left.row,
+                column,
+            };
+            let criteria_header = self.evaluate_cell(cell);
+            if let Ok(s) = self.cast_to_string(criteria_header, cell) {
+                // Non-empty string header. If the header is non string we skip it
+                header_count += 1;
+                let wanted = s.to_lowercase();
+
+                // Find corresponding Database column
+                let mut found = false;
+                for db_column in db_left.column..=db_right.column {
+                    let db_header = self.evaluate_cell(CellReferenceIndex {
+                        sheet: db_left.sheet,
+                        row: db_left.row,
+                        column: db_column,
+                    });
+                    if let Ok(hs) = self.cast_to_string(db_header, cell) {
+                        if hs.to_lowercase() == wanted {
+                            crit_cols.push(db_column);
+                            found = true;
+                            break;
+                        }
+                    }
+                }
+                if !found {
+                    // that means the criteria column has no matching DB column
+                    // If the criteria condition is empty then we remove this condition
+                    // otherwise this condition can never be satisfied
+                    // We evaluate all criteria rows to see if any is non-empty
+                    let mut has_non_empty = false;
+                    for r in (c_left.row + 1)..=c_right.row {
+                        let ccell = self.evaluate_cell(CellReferenceIndex {
+                            sheet: c_left.sheet,
+                            row: r,
+                            column,
+                        });
+                        if !matches!(ccell, CalcResult::EmptyCell | CalcResult::EmptyArg) {
+                            has_non_empty = true;
+                            break;
+                        }
+                    }
+                    if has_non_empty {
+                        // This criteria column can never be satisfied
+                        header_count -= 1;
+                    }
+                }
+            };
+        }
+
+        if c_right.row <= c_left.row {
+            // If no criteria rows (only headers), everything matches
+            return true;
+        }
+
+        if header_count == 0 {
+            // If there are not "String" headers, nothing matches
+            // NB: There might be String headers that do not match any DB columns,
+            // in that case everything matches.
+            return false;
+        }
+
+        // Evaluate each criteria row (OR)
+        for r in (c_left.row + 1)..=c_right.row {
+            // AND across columns for this criteria row
+            let mut and_ok = true;
+
+            for (offset, db_col) in crit_cols.iter().enumerate() {
+                // Criteria cell
+                let ccell = self.evaluate_cell(CellReferenceIndex {
+                    sheet: c_left.sheet,
+                    row: r,
+                    column: c_left.column + offset as i32,
+                });
+
+                // Empty criteria cell -> ignored
+                if matches!(ccell, CalcResult::EmptyCell | CalcResult::EmptyArg) {
+                    continue;
+                }
+
+                // Database value for this row/column
+                let db_val = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: *db_col,
+                });
+
+                if !self.criteria_cell_matches(&db_val, &ccell) {
+                    and_ok = false;
+                    break;
+                }
+            }
+
+            if and_ok {
+                // This criteria row satisfied (OR)
+                return true;
+            }
+        }
+
+        // none matched
+        false
+    }
+
+    /// Implements Excel-like criteria matching for a single value.
+    /// Supports prefixes: <>, >=, <=, >, <, = ; wildcards * and ? for string equals.
+    fn criteria_cell_matches(&self, db_val: &CalcResult, crit_cell: &CalcResult) -> bool {
+        // Convert the criteria cell to a string for operator parsing if possible,
+        // otherwise fall back to equality via compare_values.
+
+        let mut criteria = match crit_cell {
+            CalcResult::String(s) => s.trim().to_string(),
+            CalcResult::Number(n) => {
+                // treat as equality with number
+                return match db_val {
+                    CalcResult::Number(v) => (*v - *n).abs() <= f64::EPSILON,
+                    _ => false,
+                };
+            }
+            CalcResult::Boolean(b) => {
+                // check equality with boolean
+                return match db_val {
+                    CalcResult::Boolean(v) => *v == *b,
+                    _ => false,
+                };
+            }
+            CalcResult::EmptyCell | CalcResult::EmptyArg => "".to_string(),
+            CalcResult::Error { .. } => return false,
+            CalcResult::Range { .. } | CalcResult::Array(_) => return false,
+        };
+
+        // Detect operator prefix
+        let mut op = "="; // default equality (with wildcard semantics for strings)
+        let prefixes = ["<>", ">=", "<=", ">", "<", "="];
+        for p in prefixes.iter() {
+            if criteria.starts_with(p) {
+                op = p;
+                criteria = criteria[p.len()..].trim().to_string();
+                break;
+            }
+        }
+
+        // Is it a number?
+        let rhs_num = criteria.parse::<f64>().ok();
+
+        // Is it a date?
+        // FIXME: We should parse dates according to locale settings
+        let rhs_date = criteria.parse::<chrono::NaiveDate>().ok();
+
+        match op {
+            ">" | ">=" | "<" | "<=" => {
+                if let Some(d) = rhs_date {
+                    // date comparison
+                    let serial = match date_to_serial_number(d.day(), d.month(), d.year()) {
+                        Ok(sn) => sn as f64,
+                        Err(_) => return false,
+                    };
+
+                    if let CalcResult::Number(n) = db_val {
+                        match op {
+                            ">" => *n > serial,
+                            ">=" => *n >= serial,
+                            "<" => *n < serial,
+                            "<=" => *n <= serial,
+                            _ => false,
+                        }
+                    } else {
+                        false
+                    }
+                } else if let Some(t) = rhs_num {
+                    // numeric comparison
+                    if let CalcResult::Number(n) = db_val {
+                        match op {
+                            ">" => *n > t,
+                            ">=" => *n >= t,
+                            "<" => *n < t,
+                            "<=" => *n <= t,
+                            _ => false,
+                        }
+                    } else {
+                        false
+                    }
+                } else {
+                    // string comparison (case-insensitive) using compare_values semantics
+                    let rhs = CalcResult::String(criteria.to_lowercase());
+                    let lhs = match db_val {
+                        CalcResult::String(s) => CalcResult::String(s.to_lowercase()),
+                        x => x.clone(),
+                    };
+                    let c = compare_values(&lhs, &rhs);
+                    match op {
+                        ">" => c > 0,
+                        ">=" => c >= 0,
+                        "<" => c < 0,
+                        "<=" => c <= 0,
+                        _ => false,
+                    }
+                }
+            }
+            "<>" => {
+                // not equal (with wildcard semantics for strings)
+                // If rhs has wildcards and db_val is string, do regex; else use compare_values != 0
+                if let CalcResult::String(s) = db_val {
+                    if criteria.contains('*') || criteria.contains('?') {
+                        if let Ok(re) = from_wildcard_to_regex(&criteria.to_lowercase(), true) {
+                            return !result_matches_regex(
+                                &CalcResult::String(s.to_lowercase()),
+                                &re,
+                            );
+                        }
+                    }
+                }
+                let rhs = if let Some(n) = rhs_num {
+                    CalcResult::Number(n)
+                } else {
+                    CalcResult::String(criteria.to_lowercase())
+                };
+                let lhs = match db_val {
+                    CalcResult::String(s) => CalcResult::String(s.to_lowercase()),
+                    x => x.clone(),
+                };
+                compare_values(&lhs, &rhs) != 0
+            }
+            _ => {
+                // equality. For strings, support wildcards (*, ?)
+                if let Some(n) = rhs_num {
+                    // numeric equals
+                    if let CalcResult::Number(m) = db_val {
+                        (*m - n).abs() <= f64::EPSILON
+                    } else {
+                        compare_values(db_val, &CalcResult::Number(n)) == 0
+                    }
+                } else {
+                    // textual/boolean equals (case-insensitive), wildcard-enabled for strings
+                    if let CalcResult::String(s) = db_val {
+                        if criteria.contains('*') || criteria.contains('?') {
+                            if let Ok(re) = from_wildcard_to_regex(&criteria.to_lowercase(), true) {
+                                return result_matches_regex(
+                                    &CalcResult::String(s.to_lowercase()),
+                                    &re,
+                                );
+                            }
+                        }
+                        // This is weird but we only need to check if "starts with" for equality
+                        return s.to_lowercase().starts_with(&criteria.to_lowercase());
+                    }
+                    // Fallback: compare_values equality
+                    compare_values(db_val, &CalcResult::String(criteria.to_lowercase())) == 0
+                }
+            }
+        }
+    }
+
+    /// Shared implementation for DMAX/DMIN
+    fn db_extreme(
+        &mut self,
+        args: &[Node],
+        cell: CellReferenceIndex,
+        want_max: bool,
+    ) -> CalcResult {
+        if args.len() != 3 {
+            return CalcResult::new_args_number_error(cell);
+        }
+
+        let (db_left, db_right) = match self.get_reference(&args[0], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        let field_col = match self.resolve_db_field_column(db_left, db_right, &args[1], cell) {
+            Ok(c) => c,
+            Err(e) => return e,
+        };
+
+        let criteria = match self.get_reference(&args[2], cell) {
+            Ok(r) => (r.left, r.right),
+            Err(e) => return e,
+        };
+
+        if db_right.row <= db_left.row {
+            // no data rows
+            return CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "No data rows in database".to_string(),
+            };
+        }
+
+        let mut best: Option<f64> = None;
+
+        let mut row = db_left.row + 1;
+        while row <= db_right.row {
+            if self.db_row_matches_criteria(db_left, db_right, row, criteria) {
+                let v = self.evaluate_cell(CellReferenceIndex {
+                    sheet: db_left.sheet,
+                    row,
+                    column: field_col,
+                });
+                if let CalcResult::Number(value) = v {
+                    if value.is_finite() {
+                        best = Some(match best {
+                            None => value,
+                            Some(cur) => {
+                                if want_max {
+                                    value.max(cur)
+                                } else {
+                                    value.min(cur)
+                                }
+                            }
+                        });
+                    }
+                }
+            }
+            row += 1;
+        }
+
+        match best {
+            Some(v) => CalcResult::Number(v),
+            None => CalcResult::Number(0.0),
+        }
+    }
+}

base/src/functions/engineering/bessel.rs

@@ -1,10 +1,12 @@
+use statrs::function::erf::{erf, erfc};
+
 use crate::{
     calc_result::CalcResult,
     expressions::{parser::Node, token::Error, types::CellReferenceIndex},
     model::Model,
 };
 
-use super::transcendental::{bessel_i, bessel_j, bessel_k, bessel_y, erf};
+use super::transcendental::{bessel_i, bessel_j, bessel_k, bessel_y};
 // https://root.cern/doc/v610/TMath_8cxx_source.html
 
 // Notice that the parameters for Bessel functions in Excel and here have inverted order
@@ -160,7 +162,7 @@ impl Model {
             Ok(f) => f,
             Err(s) => return s,
         };
-        CalcResult::Number(1.0 - erf(x))
+        CalcResult::Number(erfc(x))
     }
 
     pub(crate) fn fn_erfcprecise(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
@@ -171,6 +173,6 @@ impl Model {
             Ok(f) => f,
             Err(s) => return s,
         };
-        CalcResult::Number(1.0 - erf(x))
+        CalcResult::Number(erfc(x))
     }
 }

base/src/functions/engineering/complex.rs

@@ -46,18 +46,18 @@ impl fmt::Display for Complex {
         // it is a bit weird what Excel does but it seems it uses general notation for
         // numbers > 1e-20 and scientific notation for the rest
         let y_str = if y.abs() <= 9e-20 {
-            format!("{:E}", y)
+            format!("{y:E}")
         } else if y == 1.0 {
             "".to_string()
         } else if y == -1.0 {
             "-".to_string()
         } else {
-            format!("{}", y)
+            format!("{y}")
         };
         let x_str = if x.abs() <= 9e-20 {
-            format!("{:E}", x)
+            format!("{x:E}")
         } else {
-            format!("{}", x)
+            format!("{x}")
         };
         if y == 0.0 && x == 0.0 {
             write!(f, "0")

base/src/functions/engineering/number_basis.rs

@@ -76,7 +76,7 @@ impl Model {
         if value < 0 {
             CalcResult::String(format!("{:0width$X}", HEX_MAX + value, width = 9))
         } else {
-            let result = format!("{:X}", value);
+            let result = format!("{value:X}");
             if let Some(places) = places {
                 if places < result.len() as i32 {
                     return CalcResult::new_error(
@@ -120,7 +120,7 @@ impl Model {
         if value < 0 {
             CalcResult::String(format!("{:0width$o}", OCT_MAX + value, width = 9))
         } else {
-            let result = format!("{:o}", value);
+            let result = format!("{value:o}");
             if let Some(places) = places {
                 if places < result.len() as i32 {
                     return CalcResult::new_error(
@@ -163,7 +163,7 @@ impl Model {
         if value < 0 {
             value += 1024;
         }
-        let result = format!("{:b}", value);
+        let result = format!("{value:b}");
         if let Some(places) = places {
             if value_raw > 0.0 && places < result.len() as i32 {
                 return CalcResult::new_error(Error::NUM, cell, "Out of bounds".to_string());
@@ -202,7 +202,7 @@ impl Model {
         if value < 0 {
             value += HEX_MAX;
         }
-        let result = format!("{:X}", value);
+        let result = format!("{value:X}");
         if let Some(places) = places {
             if value_raw > 0.0 && places < result.len() as i32 {
                 return CalcResult::new_error(Error::NUM, cell, "Out of bounds".to_string());
@@ -242,7 +242,7 @@ impl Model {
         if value < 0 {
             value += OCT_MAX;
         }
-        let result = format!("{:o}", value);
+        let result = format!("{value:o}");
         if let Some(places) = places {
             if value_raw > 0.0 && places < result.len() as i32 {
                 return CalcResult::new_error(Error::NUM, cell, "Out of bounds".to_string());
@@ -301,7 +301,7 @@ impl Model {
         if value < 0 {
             value += 1024;
         }
-        let result = format!("{:b}", value);
+        let result = format!("{value:b}");
         if let Some(places) = places {
             if places <= 0 || (value > 0 && places < result.len() as i32) {
                 return CalcResult::new_error(Error::NUM, cell, "Out of bounds".to_string());
@@ -391,7 +391,7 @@ impl Model {
         if value < 0 {
             value += OCT_MAX;
         }
-        let result = format!("{:o}", value);
+        let result = format!("{value:o}");
         if let Some(places) = places {
             if places <= 0 || (value > 0 && places < result.len() as i32) {
                 return CalcResult::new_error(Error::NUM, cell, "Out of bounds".to_string());
@@ -446,7 +446,7 @@ impl Model {
         if value < 0 {
             value += 1024;
         }
-        let result = format!("{:b}", value);
+        let result = format!("{value:b}");
         if let Some(places) = places {
             if value < 512 && places < result.len() as i32 {
                 return CalcResult::new_error(Error::NUM, cell, "Out of bounds".to_string());
@@ -532,7 +532,7 @@ impl Model {
         if value < 0 {
             value += HEX_MAX;
         }
-        let result = format!("{:X}", value);
+        let result = format!("{value:X}");
         if let Some(places) = places {
             if value < HEX_MAX_HALF && places < result.len() as i32 {
                 return CalcResult::new_error(Error::NUM, cell, "Out of bounds".to_string());

base/src/functions/engineering/transcendental/erf.rs

@@ -1,53 +0,0 @@
-pub(crate) fn erf(x: f64) -> f64 {
-    let cof = vec![
-        -1.3026537197817094,
-        6.419_697_923_564_902e-1,
-        1.9476473204185836e-2,
-        -9.561_514_786_808_63e-3,
-        -9.46595344482036e-4,
-        3.66839497852761e-4,
-        4.2523324806907e-5,
-        -2.0278578112534e-5,
-        -1.624290004647e-6,
-        1.303655835580e-6,
-        1.5626441722e-8,
-        -8.5238095915e-8,
-        6.529054439e-9,
-        5.059343495e-9,
-        -9.91364156e-10,
-        -2.27365122e-10,
-        9.6467911e-11,
-        2.394038e-12,
-        -6.886027e-12,
-        8.94487e-13,
-        3.13092e-13,
-        -1.12708e-13,
-        3.81e-16,
-        7.106e-15,
-        -1.523e-15,
-        -9.4e-17,
-        1.21e-16,
-        -2.8e-17,
-    ];
-
-    let mut d = 0.0;
-    let mut dd = 0.0;
-
-    let x_abs = x.abs();
-
-    let t = 2.0 / (2.0 + x_abs);
-    let ty = 4.0 * t - 2.0;
-
-    for j in (1..=cof.len() - 1).rev() {
-        let tmp = d;
-        d = ty * d - dd + cof[j];
-        dd = tmp;
-    }
-
-    let res = t * f64::exp(-x_abs * x_abs + 0.5 * (cof[0] + ty * d) - dd);
-    if x < 0.0 {
-        res - 1.0
-    } else {
-        1.0 - res
-    }
-}

base/src/functions/engineering/transcendental/mod.rs

@@ -4,7 +4,6 @@ mod bessel_j1_y1;
 mod bessel_jn_yn;
 mod bessel_k;
 mod bessel_util;
-mod erf;
 
 #[cfg(test)]
 mod test_bessel;
@@ -13,4 +12,3 @@ pub(crate) use bessel_i::bessel_i;
 pub(crate) use bessel_jn_yn::jn as bessel_j;
 pub(crate) use bessel_jn_yn::yn as bessel_y;
 pub(crate) use bessel_k::bessel_k;
-pub(crate) use erf::erf;

base/src/functions/financial.rs

@@ -231,7 +231,7 @@ impl Model {
                             CalcResult::new_error(
                                 Error::ERROR,
                                 *cell,
-                                format!("Invalid worksheet index: '{}'", sheet),
+                                format!("Invalid worksheet index: '{sheet}'"),
                             )
                         })?
                         .dimension()
@@ -245,7 +245,7 @@ impl Model {
                             CalcResult::new_error(
                                 Error::ERROR,
                                 *cell,
-                                format!("Invalid worksheet index: '{}'", sheet),
+                                format!("Invalid worksheet index: '{sheet}'"),
                             )
                         })?
                         .dimension()

base/src/functions/information.rs

@@ -1,6 +1,6 @@
 use crate::{
     calc_result::CalcResult,
-    expressions::{parser::Node, token::Error, types::CellReferenceIndex},
+    expressions::{parser::Node, token::Error, types::CellReferenceIndex, utils::number_to_column},
     model::{Model, ParsedDefinedName},
 };
 
@@ -320,4 +320,150 @@ impl Model {
             message: "Invalid name".to_string(),
         }
     }
+
+    pub(crate) fn fn_n(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let arg_count = args.len();
+        if arg_count != 1 {
+            return CalcResult::new_args_number_error(cell);
+        }
+        let value = match self.evaluate_node_in_context(&args[0], cell) {
+            CalcResult::Number(n) => n,
+            CalcResult::String(_) => 0.0,
+            CalcResult::Boolean(f) => {
+                if f {
+                    1.0
+                } else {
+                    0.0
+                }
+            }
+            CalcResult::EmptyCell | CalcResult::EmptyArg => 0.0,
+            error @ CalcResult::Error { .. } => return error,
+            CalcResult::Range { .. } => {
+                return CalcResult::Error {
+                    error: Error::NIMPL,
+                    origin: cell,
+                    message: "Arrays not supported yet".to_string(),
+                }
+            }
+            CalcResult::Array(_) => {
+                return CalcResult::Error {
+                    error: Error::NIMPL,
+                    origin: cell,
+                    message: "Arrays not supported yet".to_string(),
+                }
+            }
+        };
+
+        CalcResult::Number(value)
+    }
+
+    pub(crate) fn fn_sheets(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let arg_count = args.len();
+        if arg_count > 1 {
+            return CalcResult::new_args_number_error(cell);
+        }
+        if arg_count == 1 {
+            return CalcResult::Error {
+                error: Error::NIMPL,
+                origin: cell,
+                message: "Sheets function with an argument is not implemented".to_string(),
+            };
+        }
+        let sheet_count = self.workbook.worksheets.len() as f64;
+        CalcResult::Number(sheet_count)
+    }
+
+    pub(crate) fn fn_cell(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        let arg_count = args.len();
+        if arg_count == 0 || arg_count > 2 {
+            return CalcResult::new_args_number_error(cell);
+        }
+        let reference = if arg_count == 2 {
+            match self.evaluate_node_with_reference(&args[1], cell) {
+                CalcResult::Range { left, right: _ } => {
+                    // we just take the left cell of the range
+                    left
+                }
+                _ => {
+                    return CalcResult::Error {
+                        error: Error::VALUE,
+                        origin: cell,
+                        message: "Argument must be a reference".to_string(),
+                    }
+                }
+            }
+        } else {
+            CellReferenceIndex {
+                sheet: cell.sheet,
+                row: cell.row,
+                column: cell.column,
+            }
+        };
+        let info_type = match self.get_string(&args[0], cell) {
+            Ok(s) => s.to_uppercase(),
+            Err(e) => return e,
+        };
+        match info_type.as_str() {
+            "ADDRESS" => {
+                if reference.sheet != cell.sheet {
+                    return CalcResult::Error {
+                        error: Error::NIMPL,
+                        origin: cell,
+                        message: "References to other sheets not implemented".to_string(),
+                    };
+                }
+                let column = match number_to_column(reference.column) {
+                    Some(c) => c,
+                    None => {
+                        return CalcResult::Error {
+                            error: Error::VALUE,
+                            origin: cell,
+                            message: "Invalid column".to_string(),
+                        }
+                    }
+                };
+                let address = format!("${}${}", column, reference.row);
+                CalcResult::String(address)
+            }
+            "COL" => CalcResult::Number(reference.column as f64),
+            "COLOR" | "FILENAME" | "FORMAT" | "PARENTHESES" | "PREFIX" | "PROTECT" | "WIDTH" => {
+                CalcResult::Error {
+                    error: Error::VALUE,
+                    origin: cell,
+                    message: "info_type not implemented".to_string(),
+                }
+            }
+            "CONTENTS" => self.evaluate_cell(reference),
+            "ROW" => CalcResult::Number(reference.row as f64),
+            "TYPE" => {
+                let cell_type = match self.evaluate_cell(reference) {
+                    CalcResult::EmptyCell => "b",
+                    CalcResult::String(_) => "l",
+                    CalcResult::Number(_) => "v",
+                    CalcResult::Boolean(_) => "v",
+                    CalcResult::Error { .. } => "v",
+                    CalcResult::Range { .. } => "v",
+                    CalcResult::EmptyArg => "v",
+                    CalcResult::Array(_) => "v",
+                };
+                CalcResult::String(cell_type.to_string())
+            }
+            _ => CalcResult::Error {
+                error: Error::VALUE,
+                origin: cell,
+                message: "Invalid info_type".to_string(),
+            },
+        }
+    }
+
+    pub(crate) fn fn_info(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        if args.is_empty() || args.len() > 2 {
+            return CalcResult::new_args_number_error(cell);
+        }
+        CalcResult::Error {
+            error: Error::NIMPL,
+            origin: cell,
+            message: "Info function not implemented".to_string(),
+        }
+    }
 }

base/src/functions/logical.rs

@@ -246,7 +246,7 @@ impl Model {
         }
         // None of the cases matched so we return the default
         // If there is an even number of args is the last one otherwise is #N/A
-        if args_count % 2 == 0 {
+        if args_count.is_multiple_of(2) {
             return self.evaluate_node_in_context(&args[args_count - 1], cell);
         }
         CalcResult::Error {
@@ -262,7 +262,7 @@ impl Model {
         if args_count < 2 {
             return CalcResult::new_args_number_error(cell);
         }
-        if args_count % 2 != 0 {
+        if !args_count.is_multiple_of(2) {
             // Missing value for last condition
             return CalcResult::new_args_number_error(cell);
         }

base/src/functions/macros.rs

@@ -68,14 +68,14 @@ macro_rules! single_number_fn {
                                 },
                                 // If String, parse to f64 then apply or #VALUE! error
                                 ArrayNode::String(s) => {
-                                    let node = match s.parse::<f64>() {
+                                    let node = match self.cast_number(&s) {
-                                        Ok(f) => match $op(f) {
+                                        Some(f) => match $op(f) {
                                             Ok(x) => ArrayNode::Number(x),
                                             Err(Error::DIV) => ArrayNode::Error(Error::DIV),
                                             Err(Error::VALUE) => ArrayNode::Error(Error::VALUE),
                                             Err(e) => ArrayNode::Error(e),
                                         },
-                                        Err(_) => ArrayNode::Error(Error::VALUE),
+                                        None => ArrayNode::Error(Error::VALUE),
                                     };
                                     data_row.push(node);
                                 }

base/src/functions/math_util.rs

@@ -0,0 +1,200 @@
+/// Parse Roman (classic or Excel variants) → number
+pub fn from_roman(s: &str) -> Result<u32, String> {
+    if s.is_empty() {
+        return Err("empty numeral".into());
+    }
+    fn val(c: char) -> Option<u32> {
+        Some(match c {
+            'I' => 1,
+            'V' => 5,
+            'X' => 10,
+            'L' => 50,
+            'C' => 100,
+            'D' => 500,
+            'M' => 1000,
+            _ => return None,
+        })
+    }
+
+    // Accept the union of subtractive pairs used by the tables above (Excel-compatible).
+    fn allowed_subtractive(a: char, b: char) -> bool {
+        matches!(
+            (a, b),
+            // classic:
+            ('I','V')|('I','X')|('X','L')|('X','C')|('C','D')|('C','M')
+            // Excel forms:
+            |('V','L')|('L','D')|('L','M') // VL, LD, LM
+            |('X','D')|('X','M')          // XD, XM
+            |('V','M')                    // VM
+            |('I','L')|('I','C')|('I','D')|('I','M') // IL, IC, ID, IM
+            |('V','D')|('V','C') // VD, VC
+        )
+    }
+
+    let chars: Vec<char> = s.chars().map(|c| c.to_ascii_uppercase()).collect();
+    let mut total = 0u32;
+    let mut i = 0usize;
+
+    // Repetition rules similar to classic Romans:
+    // V, L, D cannot repeat; I, X, C, M max 3 in a row.
+    let mut last_char: Option<char> = None;
+    let mut run_len = 0usize;
+
+    while i < chars.len() {
+        let c = chars[i];
+        let v = val(c).ok_or_else(|| format!("invalid character '{c}'"))?;
+
+        if Some(c) == last_char {
+            run_len += 1;
+            match c {
+                'V' | 'L' | 'D' => return Err(format!("invalid repetition of '{c}'")),
+                _ if run_len >= 3 => return Err(format!("invalid repetition of '{c}'")),
+                _ => {}
+            }
+        } else {
+            last_char = Some(c);
+            run_len = 0;
+        }
+
+        if i + 1 < chars.len() {
+            let c2 = chars[i + 1];
+            let v2 = val(c2).ok_or_else(|| format!("invalid character '{c2}'"))?;
+            if v < v2 {
+                if !allowed_subtractive(c, c2) {
+                    return Err(format!("invalid subtractive pair '{c}{c2}'"));
+                }
+                // Disallow stacked subtractives like IIV, XXL:
+                if run_len > 0 {
+                    return Err(format!("malformed numeral near position {i}"));
+                }
+                total += v2 - v;
+                i += 2;
+                last_char = None;
+                run_len = 0;
+                continue;
+            }
+        }
+
+        total += v;
+        i += 1;
+    }
+    Ok(total)
+}
+
+/// Classic Roman (strict) encoder used as a base for all forms.
+fn to_roman(mut n: u32) -> Result<String, String> {
+    if !(1..=3999).contains(&n) {
+        return Err("value out of range (must be 1..=3999)".into());
+    }
+
+    const MAP: &[(u32, &str)] = &[
+        (1000, "M"),
+        (900, "CM"),
+        (500, "D"),
+        (400, "CD"),
+        (100, "C"),
+        (90, "XC"),
+        (50, "L"),
+        (40, "XL"),
+        (10, "X"),
+        (9, "IX"),
+        (5, "V"),
+        (4, "IV"),
+        (1, "I"),
+    ];
+
+    let mut out = String::with_capacity(15);
+    for &(val, sym) in MAP {
+        while n >= val {
+            out.push_str(sym);
+            n -= val;
+        }
+        if n == 0 {
+            break;
+        }
+    }
+    Ok(out)
+}
+
+/// Excel/Google Sheets compatible ROMAN(number, [form]) encoder.
+/// `form`: 0..=4 (0=Classic, 4=Simplified).
+pub fn to_roman_with_form(n: u32, form: i32) -> Result<String, String> {
+    let mut s = to_roman(n)?;
+    if form == 0 {
+        return Ok(s);
+    }
+    if !(0..=4).contains(&form) {
+        return Err("form must be between 0 and 4".into());
+    }
+
+    // Base rules (apply for all f >= 1)
+    let base_rules: &[(&str, &str)] = &[
+        // C(D|M)XC -> L$1XL
+        ("CDXC", "LDXL"),
+        ("CMXC", "LMXL"),
+        // C(D|M)L -> L$1
+        ("CDL", "LD"),
+        ("CML", "LM"),
+        // X(L|C)IX -> V$1IV
+        ("XLIX", "VLIV"),
+        ("XCIX", "VCIV"),
+        // X(L|C)V -> V$1
+        ("XLV", "VL"),
+        ("XCV", "VC"),
+    ];
+
+    // Level 2 extra rules
+    let lvl2_rules: &[(&str, &str)] = &[
+        // V(L|C)IV -> I$1
+        ("VLIV", "IL"),
+        ("VCIV", "IC"),
+        // L(D|M)XL -> X$1
+        ("LDXL", "XD"),
+        ("LMXL", "XM"),
+        // L(D|M)VL -> X$1V
+        ("LDVL", "XDV"),
+        ("LMVL", "XMV"),
+        // L(D|M)IL -> X$1IX
+        ("LDIL", "XDIX"),
+        ("LMIL", "XMIX"),
+    ];
+
+    // Level 3 extra rules
+    let lvl3_rules: &[(&str, &str)] = &[
+        // X(D|M)V -> V$1
+        ("XDV", "VD"),
+        ("XMV", "VM"),
+        // X(D|M)IX -> V$1IV
+        ("XDIX", "VDIV"),
+        ("XMIX", "VMIV"),
+    ];
+
+    // Level 4 extra rules
+    let lvl4_rules: &[(&str, &str)] = &[
+        // V(D|M)IV -> I$1
+        ("VDIV", "ID"),
+        ("VMIV", "IM"),
+    ];
+
+    // Helper to apply a batch of (from -> to) globally, in order.
+    fn apply_rules(mut t: String, rules: &[(&str, &str)]) -> String {
+        for (from, to) in rules {
+            if t.contains(from) {
+                t = t.replace(from, to);
+            }
+        }
+        t
+    }
+
+    s = apply_rules(s, base_rules);
+    if form >= 2 {
+        s = apply_rules(s, lvl2_rules);
+    }
+    if form >= 3 {
+        s = apply_rules(s, lvl3_rules);
+    }
+    if form >= 4 {
+        s = apply_rules(s, lvl4_rules);
+    }
+    Ok(s)
+}

base/src/functions/mod.rs

@@ -8,6 +8,7 @@ use crate::{
 };
 
 pub(crate) mod binary_search;
+mod database;
 mod date_and_time;
 mod engineering;
 mod financial;
@@ -16,6 +17,7 @@ mod information;
 mod logical;
 mod lookup_and_reference;
 mod macros;
+mod math_util;
 mod mathematical;
 mod statistical;
 mod subtotal;
@@ -54,6 +56,9 @@ pub enum Function {
     Columns,
     Cos,
     Cosh,
+    Log,
+    Log10,
+    Ln,
     Max,
     Min,
     Pi,
@@ -73,6 +78,43 @@ pub enum Function {
     Sumifs,
     Tan,
     Tanh,
+    Acot,
+    Acoth,
+    Cot,
+    Coth,
+    Csc,
+    Csch,
+    Sec,
+    Sech,
+    Exp,
+    Fact,
+    Factdouble,
+    Sign,
+    Radians,
+    Degrees,
+    Int,
+    Even,
+    Odd,
+    Ceiling,
+    CeilingMath,
+    CeilingPrecise,
+    Floor,
+    FloorMath,
+    FloorPrecise,
+    IsoCeiling,
+    Mod,
+    Quotient,
+    Mround,
+    Trunc,
+    Gcd,
+    Lcm,
+    Base,
+    Decimal,
+    Roman,
+    Arabic,
+    Combin,
+    Combina,
+    Sumsq,
 
     // Information
     ErrorType,
@@ -93,6 +135,11 @@ pub enum Function {
     Sheet,
     Type,
 
+    Sheets,
+    N,
+    Cell,
+    Info,
+
     // Lookup and reference
     Hlookup,
     Index,
@@ -145,13 +192,30 @@ pub enum Function {
 
     // Date and time
     Date,
+    Datedif,
+    Datevalue,
     Day,
     Edate,
     Eomonth,
     Month,
+    Time,
+    Timevalue,
+    Hour,
+    Minute,
+    Second,
     Now,
     Today,
     Year,
+    Networkdays,
+    NetworkdaysIntl,
+    Days,
+    Days360,
+    Weekday,
+    Weeknum,
+    Workday,
+    WorkdayIntl,
+    Yearfrac,
+    Isoweeknum,
 
     // Financial
     Cumipmt,
@@ -247,10 +311,24 @@ pub enum Function {
     Delta,
     Gestep,
     Subtotal,
+
+    // Database
+    Daverage,
+    Dcount,
+    Dget,
+    Dmax,
+    Dmin,
+    Dsum,
+    Dcounta,
+    Dproduct,
+    Dstdev,
+    Dvar,
+    Dvarp,
+    Dstdevp,
 }
 
 impl Function {
-    pub fn into_iter() -> IntoIter<Function, 195> {
+    pub fn into_iter() -> IntoIter<Function, 268> {
         [
             Function::And,
             Function::False,
@@ -277,15 +355,50 @@ impl Function {
             Function::Atanh,
             Function::Abs,
             Function::Pi,
+            Function::Ln,
+            Function::Log,
+            Function::Log10,
             Function::Sqrt,
             Function::Sqrtpi,
             Function::Atan2,
+            Function::Acot,
+            Function::Acoth,
+            Function::Cot,
+            Function::Coth,
+            Function::Csc,
+            Function::Csch,
+            Function::Sec,
+            Function::Sech,
             Function::Power,
+            Function::Exp,
+            Function::Fact,
+            Function::Factdouble,
+            Function::Sign,
+            Function::Int,
+            Function::Even,
+            Function::Odd,
+            Function::Ceiling,
+            Function::CeilingMath,
+            Function::CeilingPrecise,
+            Function::Floor,
+            Function::FloorMath,
+            Function::FloorPrecise,
+            Function::IsoCeiling,
+            Function::Mod,
+            Function::Quotient,
+            Function::Mround,
+            Function::Trunc,
+            Function::Gcd,
+            Function::Lcm,
+            Function::Base,
+            Function::Decimal,
             Function::Max,
             Function::Min,
             Function::Product,
             Function::Rand,
             Function::Randbetween,
+            Function::Radians,
+            Function::Degrees,
             Function::Round,
             Function::Rounddown,
             Function::Roundup,
@@ -356,9 +469,26 @@ impl Function {
             Function::Month,
             Function::Eomonth,
             Function::Date,
+            Function::Datedif,
+            Function::Datevalue,
             Function::Edate,
+            Function::Networkdays,
+            Function::NetworkdaysIntl,
+            Function::Time,
+            Function::Timevalue,
+            Function::Hour,
+            Function::Minute,
+            Function::Second,
             Function::Today,
             Function::Now,
+            Function::Days,
+            Function::Days360,
+            Function::Weekday,
+            Function::Weeknum,
+            Function::Workday,
+            Function::WorkdayIntl,
+            Function::Yearfrac,
+            Function::Isoweeknum,
             Function::Pmt,
             Function::Pv,
             Function::Rate,
@@ -447,6 +577,27 @@ impl Function {
             Function::Delta,
             Function::Gestep,
             Function::Subtotal,
+            Function::Roman,
+            Function::Arabic,
+            Function::Combin,
+            Function::Combina,
+            Function::Sumsq,
+            Function::N,
+            Function::Cell,
+            Function::Info,
+            Function::Sheets,
+            Function::Daverage,
+            Function::Dcount,
+            Function::Dget,
+            Function::Dmax,
+            Function::Dmin,
+            Function::Dsum,
+            Function::Dcounta,
+            Function::Dproduct,
+            Function::Dstdev,
+            Function::Dvar,
+            Function::Dvarp,
+            Function::Dstdevp,
         ]
         .into_iter()
     }
@@ -488,6 +639,27 @@ impl Function {
             Function::Isformula => "_xlfn.ISFORMULA".to_string(),
             Function::Sheet => "_xlfn.SHEET".to_string(),
             Function::Formulatext => "_xlfn.FORMULATEXT".to_string(),
+            Function::Isoweeknum => "_xlfn.ISOWEEKNUM".to_string(),
+            Function::Ceiling => "_xlfn.CEILING".to_string(),
+            Function::CeilingMath => "_xlfn.CEILING.MATH".to_string(),
+            Function::CeilingPrecise => "_xlfn.CEILING.PRECISE".to_string(),
+            Function::FloorMath => "_xlfn.FLOOR.MATH".to_string(),
+            Function::FloorPrecise => "_xlfn.FLOOR.PRECISE".to_string(),
+            Function::IsoCeiling => "_xlfn.ISO.CEILING".to_string(),
+            Function::Base => "_xlfn.BASE".to_string(),
+            Function::Decimal => "_xlfn.DECIMAL".to_string(),
+            Function::Arabic => "_xlfn.ARABIC".to_string(),
+            Function::Combina => "_xlfn.COMBINA".to_string(),
+            Function::Sheets => "_xlfn.SHEETS".to_string(),
+            Function::Acoth => "_xlfn.ACOTH".to_string(),
+            Function::Cot => "_xlfn.COT".to_string(),
+            Function::Coth => "_xlfn.COTH".to_string(),
+            Function::Csc => "_xlfn.CSC".to_string(),
+            Function::Csch => "_xlfn.CSCH".to_string(),
+            Function::Sec => "_xlfn.SEC".to_string(),
+            Function::Sech => "_xlfn.SECH".to_string(),
+            Function::Acot => "_xlfn.ACOT".to_string(),
+
             _ => self.to_string(),
         }
     }
@@ -510,30 +682,61 @@ impl Function {
             "SWITCH" | "_XLFN.SWITCH" => Some(Function::Switch),
             "TRUE" => Some(Function::True),
             "XOR" | "_XLFN.XOR" => Some(Function::Xor),
-
             "SIN" => Some(Function::Sin),
             "COS" => Some(Function::Cos),
             "TAN" => Some(Function::Tan),
-
             "ASIN" => Some(Function::Asin),
             "ACOS" => Some(Function::Acos),
             "ATAN" => Some(Function::Atan),
-
             "SINH" => Some(Function::Sinh),
             "COSH" => Some(Function::Cosh),
             "TANH" => Some(Function::Tanh),
-
             "ASINH" => Some(Function::Asinh),
             "ACOSH" => Some(Function::Acosh),
             "ATANH" => Some(Function::Atanh),
-
+            "ACOT" | "_XLFN.ACOT" => Some(Function::Acot),
+            "COTH" | "_XLFN.COTH" => Some(Function::Coth),
+            "COT" | "_XLFN.COT" => Some(Function::Cot),
+            "CSC" | "_XLFN.CSC" => Some(Function::Csc),
+            "CSCH" | "_XLFN.CSCH" => Some(Function::Csch),
+            "SEC" | "_XLFN.SEC" => Some(Function::Sec),
+            "SECH" | "_XLFN.SECH" => Some(Function::Sech),
+            "ACOTH" | "_XLFN.ACOTH" => Some(Function::Acoth),
+            "FACT" => Some(Function::Fact),
+            "FACTDOUBLE" => Some(Function::Factdouble),
+            "EXP" => Some(Function::Exp),
+            "SIGN" => Some(Function::Sign),
+            "RADIANS" => Some(Function::Radians),
+            "DEGREES" => Some(Function::Degrees),
+            "INT" => Some(Function::Int),
+            "EVEN" => Some(Function::Even),
+            "ODD" => Some(Function::Odd),
+            "CEILING" | "_XLFN.CEILING" => Some(Function::Ceiling),
+            "CEILING.MATH" | "_XLFN.CEILING.MATH" => Some(Function::CeilingMath),
+            "CEILING.PRECISE" | "_XLFN.CEILING.PRECISE" => Some(Function::CeilingPrecise),
+            "FLOOR" => Some(Function::Floor),
+            "FLOOR.MATH" | "_XLFN.FLOOR.MATH" => Some(Function::FloorMath),
+            "FLOOR.PRECISE" | "_XLFN.FLOOR.PRECISE" => Some(Function::FloorPrecise),
+            "ISO.CEILING" | "_XLFN.ISO.CEILING" => Some(Function::IsoCeiling),
+            "MOD" => Some(Function::Mod),
+            "QUOTIENT" => Some(Function::Quotient),
+            "MROUND" => Some(Function::Mround),
+            "TRUNC" => Some(Function::Trunc),
+            "GCD" => Some(Function::Gcd),
+            "LCM" => Some(Function::Lcm),
+            "BASE" | "_XLFN.BASE" => Some(Function::Base),
+            "DECIMAL" | "_XLFN.DECIMAL" => Some(Function::Decimal),
+            "ROMAN" => Some(Function::Roman),
+            "ARABIC" | "_XLFN.ARABIC" => Some(Function::Arabic),
             "PI" => Some(Function::Pi),
             "ABS" => Some(Function::Abs),
             "SQRT" => Some(Function::Sqrt),
             "SQRTPI" => Some(Function::Sqrtpi),
             "POWER" => Some(Function::Power),
             "ATAN2" => Some(Function::Atan2),
-
+            "LN" => Some(Function::Ln),
+            "LOG" => Some(Function::Log),
+            "LOG10" => Some(Function::Log10),
             "MAX" => Some(Function::Max),
             "MIN" => Some(Function::Min),
             "PRODUCT" => Some(Function::Product),
@@ -545,6 +748,9 @@ impl Function {
             "SUM" => Some(Function::Sum),
             "SUMIF" => Some(Function::Sumif),
             "SUMIFS" => Some(Function::Sumifs),
+            "COMBIN" => Some(Function::Combin),
+            "COMBINA" | "_XLFN.COMBINA" => Some(Function::Combina),
+            "SUMSQ" => Some(Function::Sumsq),
 
             // Lookup and Reference
             "CHOOSE" => Some(Function::Choose),
@@ -621,9 +827,26 @@ impl Function {
             "EOMONTH" => Some(Function::Eomonth),
             "MONTH" => Some(Function::Month),
             "DATE" => Some(Function::Date),
+            "DATEDIF" => Some(Function::Datedif),
+            "DATEVALUE" => Some(Function::Datevalue),
             "EDATE" => Some(Function::Edate),
+            "NETWORKDAYS" => Some(Function::Networkdays),
+            "NETWORKDAYS.INTL" => Some(Function::NetworkdaysIntl),
+            "TIME" => Some(Function::Time),
+            "TIMEVALUE" => Some(Function::Timevalue),
+            "HOUR" => Some(Function::Hour),
+            "MINUTE" => Some(Function::Minute),
+            "SECOND" => Some(Function::Second),
             "TODAY" => Some(Function::Today),
             "NOW" => Some(Function::Now),
+            "DAYS" | "_XLFN.DAYS" => Some(Function::Days),
+            "DAYS360" => Some(Function::Days360),
+            "WEEKDAY" => Some(Function::Weekday),
+            "WEEKNUM" => Some(Function::Weeknum),
+            "WORKDAY" => Some(Function::Workday),
+            "WORKDAY.INTL" => Some(Function::WorkdayIntl),
+            "YEARFRAC" => Some(Function::Yearfrac),
+            "ISOWEEKNUM" | "_XLFN.ISOWEEKNUM" => Some(Function::Isoweeknum),
             // Financial
             "PMT" => Some(Function::Pmt),
             "PV" => Some(Function::Pv),
@@ -715,6 +938,25 @@ impl Function {
             "GESTEP" => Some(Function::Gestep),
 
             "SUBTOTAL" => Some(Function::Subtotal),
+
+            "N" => Some(Function::N),
+            "CELL" => Some(Function::Cell),
+            "INFO" => Some(Function::Info),
+            "SHEETS" | "_XLFN.SHEETS" => Some(Function::Sheets),
+
+            "DAVERAGE" => Some(Function::Daverage),
+            "DCOUNT" => Some(Function::Dcount),
+            "DGET" => Some(Function::Dget),
+            "DMAX" => Some(Function::Dmax),
+            "DMIN" => Some(Function::Dmin),
+            "DSUM" => Some(Function::Dsum),
+            "DCOUNTA" => Some(Function::Dcounta),
+            "DPRODUCT" => Some(Function::Dproduct),
+            "DSTDEV" => Some(Function::Dstdev),
+            "DVAR" => Some(Function::Dvar),
+            "DVARP" => Some(Function::Dvarp),
+            "DSTDEVP" => Some(Function::Dstdevp),
+
             _ => None,
         }
     }
@@ -734,6 +976,9 @@ impl fmt::Display for Function {
             Function::Switch => write!(f, "SWITCH"),
             Function::True => write!(f, "TRUE"),
             Function::Xor => write!(f, "XOR"),
+            Function::Log => write!(f, "LOG"),
+            Function::Log10 => write!(f, "LOG10"),
+            Function::Ln => write!(f, "LN"),
             Function::Sin => write!(f, "SIN"),
             Function::Cos => write!(f, "COS"),
             Function::Tan => write!(f, "TAN"),
@@ -746,6 +991,14 @@ impl fmt::Display for Function {
             Function::Asinh => write!(f, "ASINH"),
             Function::Acosh => write!(f, "ACOSH"),
             Function::Atanh => write!(f, "ATANH"),
+            Function::Acot => write!(f, "ACOT"),
+            Function::Acoth => write!(f, "ACOTH"),
+            Function::Cot => write!(f, "COT"),
+            Function::Coth => write!(f, "COTH"),
+            Function::Csc => write!(f, "CSC"),
+            Function::Csch => write!(f, "CSCH"),
+            Function::Sec => write!(f, "SEC"),
+            Function::Sech => write!(f, "SECH"),
             Function::Abs => write!(f, "ABS"),
             Function::Pi => write!(f, "PI"),
             Function::Sqrt => write!(f, "SQRT"),
@@ -810,7 +1063,6 @@ impl fmt::Display for Function {
             Function::Isformula => write!(f, "ISFORMULA"),
             Function::Type => write!(f, "TYPE"),
             Function::Sheet => write!(f, "SHEET"),
-
             Function::Average => write!(f, "AVERAGE"),
             Function::Averagea => write!(f, "AVERAGEA"),
             Function::Averageif => write!(f, "AVERAGEIF"),
@@ -828,9 +1080,26 @@ impl fmt::Display for Function {
             Function::Month => write!(f, "MONTH"),
             Function::Eomonth => write!(f, "EOMONTH"),
             Function::Date => write!(f, "DATE"),
+            Function::Datedif => write!(f, "DATEDIF"),
+            Function::Datevalue => write!(f, "DATEVALUE"),
             Function::Edate => write!(f, "EDATE"),
+            Function::Networkdays => write!(f, "NETWORKDAYS"),
+            Function::NetworkdaysIntl => write!(f, "NETWORKDAYS.INTL"),
+            Function::Time => write!(f, "TIME"),
+            Function::Timevalue => write!(f, "TIMEVALUE"),
+            Function::Hour => write!(f, "HOUR"),
+            Function::Minute => write!(f, "MINUTE"),
+            Function::Second => write!(f, "SECOND"),
             Function::Today => write!(f, "TODAY"),
             Function::Now => write!(f, "NOW"),
+            Function::Days => write!(f, "DAYS"),
+            Function::Days360 => write!(f, "DAYS360"),
+            Function::Weekday => write!(f, "WEEKDAY"),
+            Function::Weeknum => write!(f, "WEEKNUM"),
+            Function::Workday => write!(f, "WORKDAY"),
+            Function::WorkdayIntl => write!(f, "WORKDAY.INTL"),
+            Function::Yearfrac => write!(f, "YEARFRAC"),
+            Function::Isoweeknum => write!(f, "ISOWEEKNUM"),
             Function::Pmt => write!(f, "PMT"),
             Function::Pv => write!(f, "PV"),
             Function::Rate => write!(f, "RATE"),
@@ -918,8 +1187,53 @@ impl fmt::Display for Function {
             Function::Convert => write!(f, "CONVERT"),
             Function::Delta => write!(f, "DELTA"),
             Function::Gestep => write!(f, "GESTEP"),
-
             Function::Subtotal => write!(f, "SUBTOTAL"),
+            Function::Exp => write!(f, "EXP"),
+            Function::Fact => write!(f, "FACT"),
+            Function::Factdouble => write!(f, "FACTDOUBLE"),
+            Function::Sign => write!(f, "SIGN"),
+            Function::Radians => write!(f, "RADIANS"),
+            Function::Degrees => write!(f, "DEGREES"),
+            Function::Int => write!(f, "INT"),
+            Function::Even => write!(f, "EVEN"),
+            Function::Odd => write!(f, "ODD"),
+            Function::Ceiling => write!(f, "CEILING"),
+            Function::CeilingMath => write!(f, "CEILING.MATH"),
+            Function::CeilingPrecise => write!(f, "CEILING.PRECISE"),
+            Function::Floor => write!(f, "FLOOR"),
+            Function::FloorMath => write!(f, "FLOOR.MATH"),
+            Function::FloorPrecise => write!(f, "FLOOR.PRECISE"),
+            Function::IsoCeiling => write!(f, "ISO.CEILING"),
+            Function::Mod => write!(f, "MOD"),
+            Function::Quotient => write!(f, "QUOTIENT"),
+            Function::Mround => write!(f, "MROUND"),
+            Function::Trunc => write!(f, "TRUNC"),
+            Function::Gcd => write!(f, "GCD"),
+            Function::Lcm => write!(f, "LCM"),
+            Function::Base => write!(f, "BASE"),
+            Function::Decimal => write!(f, "DECIMAL"),
+            Function::Roman => write!(f, "ROMAN"),
+            Function::Arabic => write!(f, "ARABIC"),
+            Function::Combin => write!(f, "COMBIN"),
+            Function::Combina => write!(f, "COMBINA"),
+            Function::Sumsq => write!(f, "SUMSQ"),
+
+            Function::N => write!(f, "N"),
+            Function::Cell => write!(f, "CELL"),
+            Function::Info => write!(f, "INFO"),
+            Function::Sheets => write!(f, "SHEETS"),
+            Function::Daverage => write!(f, "DAVERAGE"),
+            Function::Dcount => write!(f, "DCOUNT"),
+            Function::Dget => write!(f, "DGET"),
+            Function::Dmax => write!(f, "DMAX"),
+            Function::Dmin => write!(f, "DMIN"),
+            Function::Dsum => write!(f, "DSUM"),
+            Function::Dcounta => write!(f, "DCOUNTA"),
+            Function::Dproduct => write!(f, "DPRODUCT"),
+            Function::Dstdev => write!(f, "DSTDEV"),
+            Function::Dvar => write!(f, "DVAR"),
+            Function::Dvarp => write!(f, "DVARP"),
+            Function::Dstdevp => write!(f, "DSTDEVP"),
         }
     }
 }
@@ -948,7 +1262,6 @@ impl Model {
         cell: CellReferenceIndex,
     ) -> CalcResult {
         match kind {
-            // Logical
             Function::And => self.fn_and(args, cell),
             Function::False => self.fn_false(args, cell),
             Function::If => self.fn_if(args, cell),
@@ -960,31 +1273,27 @@ impl Model {
             Function::Switch => self.fn_switch(args, cell),
             Function::True => self.fn_true(args, cell),
             Function::Xor => self.fn_xor(args, cell),
-            // Math and trigonometry
+            Function::Log => self.fn_log(args, cell),
+            Function::Log10 => self.fn_log10(args, cell),
+            Function::Ln => self.fn_ln(args, cell),
             Function::Sin => self.fn_sin(args, cell),
             Function::Cos => self.fn_cos(args, cell),
             Function::Tan => self.fn_tan(args, cell),
-
             Function::Asin => self.fn_asin(args, cell),
             Function::Acos => self.fn_acos(args, cell),
             Function::Atan => self.fn_atan(args, cell),
-
             Function::Sinh => self.fn_sinh(args, cell),
             Function::Cosh => self.fn_cosh(args, cell),
             Function::Tanh => self.fn_tanh(args, cell),
-
             Function::Asinh => self.fn_asinh(args, cell),
             Function::Acosh => self.fn_acosh(args, cell),
             Function::Atanh => self.fn_atanh(args, cell),
-
             Function::Pi => self.fn_pi(args, cell),
             Function::Abs => self.fn_abs(args, cell),
-
             Function::Sqrt => self.fn_sqrt(args, cell),
             Function::Sqrtpi => self.fn_sqrtpi(args, cell),
             Function::Atan2 => self.fn_atan2(args, cell),
             Function::Power => self.fn_power(args, cell),
-
             Function::Max => self.fn_max(args, cell),
             Function::Min => self.fn_min(args, cell),
             Function::Product => self.fn_product(args, cell),
@@ -996,8 +1305,6 @@ impl Model {
             Function::Sum => self.fn_sum(args, cell),
             Function::Sumif => self.fn_sumif(args, cell),
             Function::Sumifs => self.fn_sumifs(args, cell),
-
-            // Lookup and Reference
             Function::Choose => self.fn_choose(args, cell),
             Function::Column => self.fn_column(args, cell),
             Function::Columns => self.fn_columns(args, cell),
@@ -1011,7 +1318,6 @@ impl Model {
             Function::Rows => self.fn_rows(args, cell),
             Function::Vlookup => self.fn_vlookup(args, cell),
             Function::Xlookup => self.fn_xlookup(args, cell),
-            // Text
             Function::Concatenate => self.fn_concatenate(args, cell),
             Function::Exact => self.fn_exact(args, cell),
             Function::Value => self.fn_value(args, cell),
@@ -1029,7 +1335,6 @@ impl Model {
             Function::Trim => self.fn_trim(args, cell),
             Function::Unicode => self.fn_unicode(args, cell),
             Function::Upper => self.fn_upper(args, cell),
-            // Information
             Function::Isnumber => self.fn_isnumber(args, cell),
             Function::Isnontext => self.fn_isnontext(args, cell),
             Function::Istext => self.fn_istext(args, cell),
@@ -1047,7 +1352,6 @@ impl Model {
             Function::Isformula => self.fn_isformula(args, cell),
             Function::Type => self.fn_type(args, cell),
             Function::Sheet => self.fn_sheet(args, cell),
-            // Statistical
             Function::Average => self.fn_average(args, cell),
             Function::Averagea => self.fn_averagea(args, cell),
             Function::Averageif => self.fn_averageif(args, cell),
@@ -1060,16 +1364,31 @@ impl Model {
             Function::Maxifs => self.fn_maxifs(args, cell),
             Function::Minifs => self.fn_minifs(args, cell),
             Function::Geomean => self.fn_geomean(args, cell),
-            // Date and Time
             Function::Year => self.fn_year(args, cell),
             Function::Day => self.fn_day(args, cell),
             Function::Eomonth => self.fn_eomonth(args, cell),
             Function::Month => self.fn_month(args, cell),
             Function::Date => self.fn_date(args, cell),
+            Function::Datedif => self.fn_datedif(args, cell),
+            Function::Datevalue => self.fn_datevalue(args, cell),
             Function::Edate => self.fn_edate(args, cell),
+            Function::Networkdays => self.fn_networkdays(args, cell),
+            Function::NetworkdaysIntl => self.fn_networkdays_intl(args, cell),
+            Function::Time => self.fn_time(args, cell),
+            Function::Timevalue => self.fn_timevalue(args, cell),
+            Function::Hour => self.fn_hour(args, cell),
+            Function::Minute => self.fn_minute(args, cell),
+            Function::Second => self.fn_second(args, cell),
             Function::Today => self.fn_today(args, cell),
             Function::Now => self.fn_now(args, cell),
-            // Financial
+            Function::Days => self.fn_days(args, cell),
+            Function::Days360 => self.fn_days360(args, cell),
+            Function::Weekday => self.fn_weekday(args, cell),
+            Function::Weeknum => self.fn_weeknum(args, cell),
+            Function::Workday => self.fn_workday(args, cell),
+            Function::WorkdayIntl => self.fn_workday_intl(args, cell),
+            Function::Yearfrac => self.fn_yearfrac(args, cell),
+            Function::Isoweeknum => self.fn_isoweeknum(args, cell),
             Function::Pmt => self.fn_pmt(args, cell),
             Function::Pv => self.fn_pv(args, cell),
             Function::Rate => self.fn_rate(args, cell),
@@ -1103,7 +1422,6 @@ impl Model {
             Function::Db => self.fn_db(args, cell),
             Function::Cumprinc => self.fn_cumprinc(args, cell),
             Function::Cumipmt => self.fn_cumipmt(args, cell),
-            // Engineering
             Function::Besseli => self.fn_besseli(args, cell),
             Function::Besselj => self.fn_besselj(args, cell),
             Function::Besselk => self.fn_besselk(args, cell),
@@ -1158,8 +1476,60 @@ impl Model {
             Function::Convert => self.fn_convert(args, cell),
             Function::Delta => self.fn_delta(args, cell),
             Function::Gestep => self.fn_gestep(args, cell),
-
             Function::Subtotal => self.fn_subtotal(args, cell),
+            Function::Acot => self.fn_acot(args, cell),
+            Function::Acoth => self.fn_acoth(args, cell),
+            Function::Cot => self.fn_cot(args, cell),
+            Function::Coth => self.fn_coth(args, cell),
+            Function::Csc => self.fn_csc(args, cell),
+            Function::Csch => self.fn_csch(args, cell),
+            Function::Sec => self.fn_sec(args, cell),
+            Function::Sech => self.fn_sech(args, cell),
+            Function::Exp => self.fn_exp(args, cell),
+            Function::Fact => self.fn_fact(args, cell),
+            Function::Factdouble => self.fn_factdouble(args, cell),
+            Function::Sign => self.fn_sign(args, cell),
+            Function::Radians => self.fn_radians(args, cell),
+            Function::Degrees => self.fn_degrees(args, cell),
+            Function::Int => self.fn_int(args, cell),
+            Function::Even => self.fn_even(args, cell),
+            Function::Odd => self.fn_odd(args, cell),
+            Function::Ceiling => self.fn_ceiling(args, cell),
+            Function::CeilingMath => self.fn_ceiling_math(args, cell),
+            Function::CeilingPrecise => self.fn_ceiling_precise(args, cell),
+            Function::Floor => self.fn_floor(args, cell),
+            Function::FloorMath => self.fn_floor_math(args, cell),
+            Function::FloorPrecise => self.fn_floor_precise(args, cell),
+            Function::IsoCeiling => self.fn_iso_ceiling(args, cell),
+            Function::Mod => self.fn_mod(args, cell),
+            Function::Quotient => self.fn_quotient(args, cell),
+            Function::Mround => self.fn_mround(args, cell),
+            Function::Trunc => self.fn_trunc(args, cell),
+            Function::Gcd => self.fn_gcd(args, cell),
+            Function::Lcm => self.fn_lcm(args, cell),
+            Function::Base => self.fn_base(args, cell),
+            Function::Decimal => self.fn_decimal(args, cell),
+            Function::Roman => self.fn_roman(args, cell),
+            Function::Arabic => self.fn_arabic(args, cell),
+            Function::Combin => self.fn_combin(args, cell),
+            Function::Combina => self.fn_combina(args, cell),
+            Function::Sumsq => self.fn_sumsq(args, cell),
+            Function::N => self.fn_n(args, cell),
+            Function::Cell => self.fn_cell(args, cell),
+            Function::Info => self.fn_info(args, cell),
+            Function::Sheets => self.fn_sheets(args, cell),
+            Function::Daverage => self.fn_daverage(args, cell),
+            Function::Dcount => self.fn_dcount(args, cell),
+            Function::Dget => self.fn_dget(args, cell),
+            Function::Dmax => self.fn_dmax(args, cell),
+            Function::Dmin => self.fn_dmin(args, cell),
+            Function::Dsum => self.fn_dsum(args, cell),
+            Function::Dcounta => self.fn_dcounta(args, cell),
+            Function::Dproduct => self.fn_dproduct(args, cell),
+            Function::Dstdev => self.fn_dstdev(args, cell),
+            Function::Dvar => self.fn_dvar(args, cell),
+            Function::Dvarp => self.fn_dvarp(args, cell),
+            Function::Dstdevp => self.fn_dstdevp(args, cell),
         }
     }
 }
@@ -1214,7 +1584,7 @@ mod tests {
         }
         // We make a list with their functions names, but we escape ".": ERROR.TYPE => ERRORTYPE
         let iter_list = Function::into_iter()
-            .map(|f| format!("{}", f).replace('.', ""))
+            .map(|f| format!("{f}").replace('.', ""))
             .collect::<Vec<_>>();
 
         let len = iter_list.len();

base/src/functions/statistical.rs

@@ -350,7 +350,7 @@ impl Model {
     // FIXME: This function shares a lot of code with apply_ifs. Can we merge them?
     pub(crate) fn fn_countifs(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
         let args_count = args.len();
-        if args_count < 2 || args_count % 2 == 1 {
+        if args_count < 2 || !args_count.is_multiple_of(2) {
             return CalcResult::new_args_number_error(cell);
         }
 
@@ -476,7 +476,7 @@ impl Model {
         F: FnMut(f64),
     {
         let args_count = args.len();
-        if args_count < 3 || args_count % 2 == 0 {
+        if args_count < 3 || args_count.is_multiple_of(2) {
             return Err(CalcResult::new_args_number_error(cell));
         }
         let arg_0 = self.evaluate_node_in_context(&args[0], cell);

base/src/functions/text.rs

@@ -55,14 +55,14 @@ impl Model {
         let mut result = "".to_string();
         for arg in args {
             match self.evaluate_node_in_context(arg, cell) {
-                CalcResult::String(value) => result = format!("{}{}", result, value),
+                CalcResult::String(value) => result = format!("{result}{value}"),
-                CalcResult::Number(value) => result = format!("{}{}", result, value),
+                CalcResult::Number(value) => result = format!("{result}{value}"),
                 CalcResult::EmptyCell | CalcResult::EmptyArg => {}
                 CalcResult::Boolean(value) => {
                     if value {
-                        result = format!("{}TRUE", result);
+                        result = format!("{result}TRUE");
                     } else {
-                        result = format!("{}FALSE", result);
+                        result = format!("{result}FALSE");
                     }
                 }
                 error @ CalcResult::Error { .. } => return error,
@@ -82,16 +82,14 @@ impl Model {
                                 column,
                             }) {
                                 CalcResult::String(value) => {
-                                    result = format!("{}{}", result, value);
+                                    result = format!("{result}{value}");
-                                }
-                                CalcResult::Number(value) => {
-                                    result = format!("{}{}", result, value)
                                 }
+                                CalcResult::Number(value) => result = format!("{result}{value}"),
                                 CalcResult::Boolean(value) => {
                                     if value {
-                                        result = format!("{}TRUE", result);
+                                        result = format!("{result}TRUE");
                                     } else {
-                                        result = format!("{}FALSE", result);
+                                        result = format!("{result}FALSE");
                                     }
                                 }
                                 error @ CalcResult::Error { .. } => return error,
@@ -282,7 +280,7 @@ impl Model {
     pub(crate) fn fn_len(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
         if args.len() == 1 {
             let s = match self.evaluate_node_in_context(&args[0], cell) {
-                CalcResult::Number(v) => format!("{}", v),
+                CalcResult::Number(v) => format!("{v}"),
                 CalcResult::String(v) => v,
                 CalcResult::Boolean(b) => {
                     if b {
@@ -317,7 +315,7 @@ impl Model {
     pub(crate) fn fn_trim(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
         if args.len() == 1 {
             let s = match self.evaluate_node_in_context(&args[0], cell) {
-                CalcResult::Number(v) => format!("{}", v),
+                CalcResult::Number(v) => format!("{v}"),
                 CalcResult::String(v) => v,
                 CalcResult::Boolean(b) => {
                     if b {
@@ -352,7 +350,7 @@ impl Model {
     pub(crate) fn fn_lower(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
         if args.len() == 1 {
             let s = match self.evaluate_node_in_context(&args[0], cell) {
-                CalcResult::Number(v) => format!("{}", v),
+                CalcResult::Number(v) => format!("{v}"),
                 CalcResult::String(v) => v,
                 CalcResult::Boolean(b) => {
                     if b {
@@ -387,7 +385,7 @@ impl Model {
     pub(crate) fn fn_unicode(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
         if args.len() == 1 {
             let s = match self.evaluate_node_in_context(&args[0], cell) {
-                CalcResult::Number(v) => format!("{}", v),
+                CalcResult::Number(v) => format!("{v}"),
                 CalcResult::String(v) => v,
                 CalcResult::Boolean(b) => {
                     if b {
@@ -441,7 +439,7 @@ impl Model {
     pub(crate) fn fn_upper(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
         if args.len() == 1 {
             let s = match self.evaluate_node_in_context(&args[0], cell) {
-                CalcResult::Number(v) => format!("{}", v),
+                CalcResult::Number(v) => format!("{v}"),
                 CalcResult::String(v) => v,
                 CalcResult::Boolean(b) => {
                     if b {
@@ -478,7 +476,7 @@ impl Model {
             return CalcResult::new_args_number_error(cell);
         }
         let s = match self.evaluate_node_in_context(&args[0], cell) {
-            CalcResult::Number(v) => format!("{}", v),
+            CalcResult::Number(v) => format!("{v}"),
             CalcResult::String(v) => v,
             CalcResult::Boolean(b) => {
                 if b {
@@ -560,7 +558,7 @@ impl Model {
             return CalcResult::new_args_number_error(cell);
         }
         let s = match self.evaluate_node_in_context(&args[0], cell) {
-            CalcResult::Number(v) => format!("{}", v),
+            CalcResult::Number(v) => format!("{v}"),
             CalcResult::String(v) => v,
             CalcResult::Boolean(b) => {
                 if b {
@@ -642,7 +640,7 @@ impl Model {
             return CalcResult::new_args_number_error(cell);
         }
         let s = match self.evaluate_node_in_context(&args[0], cell) {
-            CalcResult::Number(v) => format!("{}", v),
+            CalcResult::Number(v) => format!("{v}"),
             CalcResult::String(v) => v,
             CalcResult::Boolean(b) => {
                 if b {

base/src/functions/util.rs

@@ -1,7 +1,10 @@
 #[cfg(feature = "use_regex_lite")]
 use regex_lite as regex;
 
-use crate::{calc_result::CalcResult, expressions::token::is_english_error_string};
+use crate::{
+    calc_result::CalcResult, expressions::token::is_english_error_string,
+    number_format::to_excel_precision,
+};
 
 /// This test for exact match (modulo case).
 ///   * strings are not cast into bools or numbers
@@ -34,6 +37,8 @@ pub(crate) fn values_are_equal(left: &CalcResult, right: &CalcResult) -> bool {
 pub(crate) fn compare_values(left: &CalcResult, right: &CalcResult) -> i32 {
     match (left, right) {
         (CalcResult::Number(value1), CalcResult::Number(value2)) => {
+            let value1 = to_excel_precision(*value1, 15);
+            let value2 = to_excel_precision(*value2, 15);
             if (value2 - value1).abs() < f64::EPSILON {
                 return 0;
             }
@@ -110,7 +115,7 @@ pub(crate) fn from_wildcard_to_regex(
 
     // And we have a valid Perl regex! (As Kim Kardashian said before me: "I know, right?")
     if exact {
-        return regex::Regex::new(&format!("^{}$", reg));
+        return regex::Regex::new(&format!("^{reg}$"));
     }
     regex::Regex::new(reg)
 }

base/src/language/mod.rs

@@ -1,7 +1,6 @@
-use std::collections::HashMap;
+use std::{collections::HashMap, sync::OnceLock};
 
 use bitcode::{Decode, Encode};
-use once_cell::sync::Lazy;
 
 #[derive(Encode, Decode, Clone)]
 pub struct Booleans {
@@ -31,14 +30,17 @@ pub struct Language {
     pub errors: Errors,
 }
 
+static LANGUAGES: OnceLock<HashMap<String, Language>> = OnceLock::new();
+
 #[allow(clippy::expect_used)]
-static LANGUAGES: Lazy<HashMap<String, Language>> = Lazy::new(|| {
+fn get_languages() -> &'static HashMap<String, Language> {
+    LANGUAGES.get_or_init(|| {
         bitcode::decode(include_bytes!("language.bin")).expect("Failed parsing language file")
-});
+    })
+}
 
 pub fn get_language(id: &str) -> Result<&Language, String> {
-    let language = LANGUAGES
+    get_languages()
         .get(id)
-        .ok_or(format!("Language is not supported: '{}'", id))?;
+        .ok_or_else(|| format!("Language is not supported: '{id}'"))
-    Ok(language)
 }

base/src/locale/mod.rs

@@ -1,7 +1,6 @@
-use bitcode::{Decode, Encode};
+use std::{collections::HashMap, sync::OnceLock};
-use once_cell::sync::Lazy;
 
-use std::collections::HashMap;
+use bitcode::{Decode, Encode};
 
 #[derive(Encode, Decode, Clone)]
 pub struct Locale {
@@ -65,12 +64,17 @@ pub struct DecimalFormats {
     pub standard: String,
 }
 
+static LOCALES: OnceLock<HashMap<String, Locale>> = OnceLock::new();
+
 #[allow(clippy::expect_used)]
-static LOCALES: Lazy<HashMap<String, Locale>> =
+fn get_locales() -> &'static HashMap<String, Locale> {
-    Lazy::new(|| bitcode::decode(include_bytes!("locales.bin")).expect("Failed parsing locale"));
+    LOCALES.get_or_init(|| {
+        bitcode::decode(include_bytes!("locales.bin")).expect("Failed parsing locale")
+    })
+}
 
 pub fn get_locale(id: &str) -> Result<&Locale, String> {
-    // TODO: pass the locale once we implement locales in Rust
+    get_locales()
-    let locale = LOCALES.get(id).ok_or("Invalid locale")?;
+        .get(id)
-    Ok(locale)
+        .ok_or_else(|| format!("Invalid locale: '{id}'"))
 }

base/src/model.rs

@@ -106,15 +106,15 @@ pub struct Model {
     pub(crate) shared_strings: HashMap<String, usize>,
     /// An instance of the parser
     pub(crate) parser: Parser,
-    /// The list of cells with formulas that are evaluated of being evaluated
+    /// The list of cells with formulas that are evaluated or being evaluated
     pub(crate) cells: HashMap<(u32, i32, i32), CellState>,
     /// The locale of the model
     pub(crate) locale: Locale,
-    /// Tha language used
+    /// The language used
     pub(crate) language: Language,
     /// The timezone used to evaluate the model
     pub(crate) tz: Tz,
-    /// The view id. A view consist of a selected sheet and ranges.
+    /// The view id. A view consists of a selected sheet and ranges.
     pub(crate) view_id: u32,
 }
 
@@ -215,7 +215,7 @@ impl Model {
                 _ => CalcResult::new_error(
                     Error::ERROR,
                     cell,
-                    format!("Error with Implicit Intersection in cell {:?}", cell),
+                    format!("Error with Implicit Intersection in cell {cell:?}"),
                 ),
             },
             _ => self.evaluate_node_in_context(node, cell),
@@ -355,7 +355,7 @@ impl Model {
                         return s;
                     }
                 };
-                let result = format!("{}{}", l, r);
+                let result = format!("{l}{r}");
                 CalcResult::String(result)
             }
             OpProductKind { kind, left, right } => match kind {
@@ -375,7 +375,7 @@ impl Model {
             }
             FunctionKind { kind, args } => self.evaluate_function(kind, args, cell),
             InvalidFunctionKind { name, args: _ } => {
-                CalcResult::new_error(Error::ERROR, cell, format!("Invalid function: {}", name))
+                CalcResult::new_error(Error::ERROR, cell, format!("Invalid function: {name}"))
             }
             ArrayKind(s) => CalcResult::Array(s.to_owned()),
             DefinedNameKind((name, scope, _)) => {
@@ -391,26 +391,26 @@ impl Model {
                         ParsedDefinedName::InvalidDefinedNameFormula => CalcResult::new_error(
                             Error::NAME,
                             cell,
-                            format!("Defined name \"{}\" is not a reference.", name),
+                            format!("Defined name \"{name}\" is not a reference."),
                         ),
                     }
                 } else {
                     CalcResult::new_error(
                         Error::NAME,
                         cell,
-                        format!("Defined name \"{}\" not found.", name),
+                        format!("Defined name \"{name}\" not found."),
                     )
                 }
             }
             TableNameKind(s) => CalcResult::new_error(
                 Error::NAME,
                 cell,
-                format!("table name \"{}\" not supported.", s),
+                format!("table name \"{s}\" not supported."),
             ),
             WrongVariableKind(s) => CalcResult::new_error(
                 Error::NAME,
                 cell,
-                format!("Variable name \"{}\" not found.", s),
+                format!("Variable name \"{s}\" not found."),
             ),
             CompareKind { kind, left, right } => {
                 let l = self.evaluate_node_in_context(left, cell);
@@ -487,7 +487,7 @@ impl Model {
             } => CalcResult::new_error(
                 Error::ERROR,
                 cell,
-                format!("Error parsing {}: {}", formula, message),
+                format!("Error parsing {formula}: {message}"),
             ),
             EmptyArgKind => CalcResult::EmptyArg,
             ImplicitIntersection {
@@ -500,7 +500,7 @@ impl Model {
                         None => CalcResult::new_error(
                             Error::VALUE,
                             cell,
-                            format!("Error with Implicit Intersection in cell {:?}", cell),
+                            format!("Error with Implicit Intersection in cell {cell:?}"),
                         ),
                     }
                 }
@@ -697,7 +697,7 @@ impl Model {
             worksheet.color = Some(color.to_string());
             return Ok(());
         }
-        Err(format!("Invalid color: {}", color))
+        Err(format!("Invalid color: {color}"))
     }
 
     /// Changes the visibility of a sheet
@@ -1027,7 +1027,7 @@ impl Model {
         let source_sheet_name = self
             .workbook
             .worksheet(source.sheet)
-            .map_err(|e| format!("Could not find source worksheet: {}", e))?
+            .map_err(|e| format!("Could not find source worksheet: {e}"))?
             .get_name();
         if source.sheet != area.sheet {
             return Err("Source and area are in different sheets".to_string());
@@ -1041,7 +1041,7 @@ impl Model {
         let target_sheet_name = self
             .workbook
             .worksheet(target.sheet)
-            .map_err(|e| format!("Could not find target worksheet: {}", e))?
+            .map_err(|e| format!("Could not find target worksheet: {e}"))?
             .get_name();
         if let Some(formula) = value.strip_prefix('=') {
             let cell_reference = CellReferenceRC {
@@ -1061,7 +1061,7 @@ impl Model {
                     column_delta: target.column - source.column,
                 },
             );
-            Ok(format!("={}", formula_str))
+            Ok(format!("={formula_str}"))
         } else {
             Ok(value.to_string())
         }
@@ -1538,7 +1538,7 @@ impl Model {
         // If the formula fails to parse try adding a parenthesis
         // SUM(A1:A3  => SUM(A1:A3)
         if let Node::ParseErrorKind { .. } = parsed_formula {
-            let new_parsed_formula = self.parser.parse(&format!("{})", formula), &cell_reference);
+            let new_parsed_formula = self.parser.parse(&format!("{formula})"), &cell_reference);
             match new_parsed_formula {
                 Node::ParseErrorKind { .. } => {}
                 _ => parsed_formula = new_parsed_formula,
@@ -1931,32 +1931,16 @@ impl Model {
     }
 
     /// Returns markup representation of the given `sheet`.
-    pub fn get_sheet_markup(
+    pub fn get_sheet_markup(&self, sheet: u32) -> Result<String, String> {
-        &self,
+        let worksheet = self.workbook.worksheet(sheet)?;
-        sheet: u32,
+        let dimension = worksheet.dimension();
-        start_row: i32,
-        start_column: i32,
-        width: i32,
-        height: i32,
-    ) -> Result<String, String> {
-        let mut table: Vec<Vec<String>> = Vec::new();
-        if start_row < 1 || start_column < 1 {
-            return Err("Start row and column must be positive".to_string());
-        }
-        if start_row + height >= LAST_ROW || start_column + width >= LAST_COLUMN {
-            return Err("Start row and column exceed the maximum allowed".to_string());
-        }
-        if height <= 0 || width <= 0 {
-            return Err("Height must be positive and width must be positive".to_string());
-        }
 
-        // a mutable vector to store the column widths of length `width + 1`
+        let mut rows = Vec::new();
-        let mut column_widths: Vec<f64> = vec![0.0; (width + 1) as usize];
 
-        for row in start_row..(start_row + height + 1) {
+        for row in 1..(dimension.max_row + 1) {
             let mut row_markup: Vec<String> = Vec::new();
 
-            for column in start_column..(start_column + width + 1) {
+            for column in 1..(dimension.max_column + 1) {
                 let mut cell_markup = match self.get_cell_formula(sheet, row, column)? {
                     Some(formula) => formula,
                     None => self.get_formatted_cell_value(sheet, row, column)?,
@@ -1965,34 +1949,12 @@ impl Model {
                 if style.font.b {
                     cell_markup = format!("**{cell_markup}**")
                 }
-                column_widths[(column - start_column) as usize] =
-                    column_widths[(column - start_column) as usize].max(cell_markup.len() as f64);
                 row_markup.push(cell_markup);
             }
 
-            table.push(row_markup);
+            rows.push(row_markup.join("|"));
         }
-        let mut rows = Vec::new();
-        for (j, row) in table.iter().enumerate() {
-            if j == 1 {
-                let mut row_markup = String::new();
-                for i in 0..(width + 1) {
-                    row_markup.push('|');
-                    let wide = column_widths[i as usize] as usize;
-                    row_markup.push_str(&"-".repeat(wide));
-                }
-                rows.push(row_markup);
-            }
-            let mut row_markup = String::new();
 
-            for (i, cell) in row.iter().enumerate() {
-                row_markup.push('|');
-                let wide = column_widths[i] as usize;
-                // Add padding to the cell content
-                row_markup.push_str(&format!("{:<wide$}", cell, wide = wide));
-            }
-            rows.push(row_markup);
-        }
         Ok(rows.join("\n"))
     }
 
@@ -2106,21 +2068,7 @@ impl Model {
         scope: Option<u32>,
         formula: &str,
     ) -> Result<(), String> {
-        if !is_valid_identifier(name) {
+        let sheet_id = self.is_valid_defined_name(name, scope, formula)?;
-            return Err("Invalid defined name".to_string());
-        };
-        let name_upper = name.to_uppercase();
-        let defined_names = &self.workbook.defined_names;
-        let sheet_id = match scope {
-            Some(index) => Some(self.workbook.worksheet(index)?.sheet_id),
-            None => None,
-        };
-        // if the defined name already exist return error
-        for df in defined_names {
-            if df.name.to_uppercase() == name_upper && df.sheet_id == sheet_id {
-                return Err("Defined name already exists".to_string());
-            }
-        }
         self.workbook.defined_names.push(DefinedName {
             name: name.to_string(),
             formula: formula.to_string(),
@@ -2131,6 +2079,48 @@ impl Model {
         Ok(())
     }
 
+    /// Validates if a defined name can be created
+    pub fn is_valid_defined_name(
+        &self,
+        name: &str,
+        scope: Option<u32>,
+        formula: &str,
+    ) -> Result<Option<u32>, String> {
+        if !is_valid_identifier(name) {
+            return Err("Name: Invalid defined name".to_string());
+        }
+        let name_upper = name.to_uppercase();
+        let defined_names = &self.workbook.defined_names;
+        let sheet_id = match scope {
+            Some(index) => match self.workbook.worksheet(index) {
+                Ok(ws) => Some(ws.sheet_id),
+                Err(_) => return Err("Scope: Invalid sheet index".to_string()),
+            },
+            None => None,
+        };
+        // if the defined name already exist return error
+        for df in defined_names {
+            if df.name.to_uppercase() == name_upper && df.sheet_id == sheet_id {
+                return Err("Name: Defined name already exists".to_string());
+            }
+        }
+
+        // Make sure the formula is valid
+        match common::ParsedReference::parse_reference_formula(
+            None,
+            formula,
+            &self.locale,
+            |name| self.get_sheet_index_by_name(name),
+        ) {
+            Ok(_) => {}
+            Err(_) => {
+                return Err("Formula: Invalid defined name formula".to_string());
+            }
+        };
+
+        Ok(sheet_id)
+    }
+
     /// Delete defined name of name and scope
     pub fn delete_defined_name(&mut self, name: &str, scope: Option<u32>) -> Result<(), String> {
         let name_upper = name.to_uppercase();
@@ -2164,7 +2154,7 @@ impl Model {
         new_formula: &str,
     ) -> Result<(), String> {
         if !is_valid_identifier(new_name) {
-            return Err("Invalid defined name".to_string());
+            return Err("Name: Invalid defined name".to_string());
         };
         let name_upper = name.to_uppercase();
         let new_name_upper = new_name.to_uppercase();
@@ -2172,18 +2162,28 @@ impl Model {
         if name_upper != new_name_upper || scope != new_scope {
             for key in self.parsed_defined_names.keys() {
                 if key.1.to_uppercase() == new_name_upper && key.0 == new_scope {
-                    return Err("Defined name already exists".to_string());
+                    return Err("Name: Defined name already exists".to_string());
                 }
             }
         }
         let defined_names = &self.workbook.defined_names;
         let sheet_id = match scope {
-            Some(index) => Some(self.workbook.worksheet(index)?.sheet_id),
+            Some(index) => Some(
+                self.workbook
+                    .worksheet(index)
+                    .map_err(|_| "Scope: Invalid sheet index")?
+                    .sheet_id,
+            ),
             None => None,
         };
 
         let new_sheet_id = match new_scope {
-            Some(index) => Some(self.workbook.worksheet(index)?.sheet_id),
+            Some(index) => Some(
+                self.workbook
+                    .worksheet(index)
+                    .map_err(|_| "Scope: Invalid sheet index")?
+                    .sheet_id,
+            ),
             None => None,
         };
 

base/src/new_empty.rs

@@ -168,11 +168,11 @@ impl Model {
             .get_worksheet_names()
             .iter()
             .map(|s| s.to_uppercase())
-            .any(|x| x == format!("{}{}", base_name_uppercase, index))
+            .any(|x| x == format!("{base_name_uppercase}{index}"))
         {
             index += 1;
         }
-        let sheet_name = format!("{}{}", base_name, index);
+        let sheet_name = format!("{base_name}{index}");
         // Now we need a sheet_id
         let sheet_id = self.get_new_sheet_id();
         let view_ids: Vec<&u32> = self.workbook.views.keys().collect();
@@ -192,7 +192,7 @@ impl Model {
         sheet_id: Option<u32>,
     ) -> Result<(), String> {
         if !is_valid_sheet_name(sheet_name) {
-            return Err(format!("Invalid name for a sheet: '{}'", sheet_name));
+            return Err(format!("Invalid name for a sheet: '{sheet_name}'"));
         }
         if self
             .workbook
@@ -234,7 +234,7 @@ impl Model {
         if let Some(sheet_index) = self.get_sheet_index_by_name(old_name) {
             return self.rename_sheet_by_index(sheet_index, new_name);
         }
-        Err(format!("Could not find sheet {}", old_name))
+        Err(format!("Could not find sheet {old_name}"))
     }
 
     /// Renames a sheet and updates all existing references to that sheet.
@@ -248,10 +248,10 @@ impl Model {
         new_name: &str,
     ) -> Result<(), String> {
         if !is_valid_sheet_name(new_name) {
-            return Err(format!("Invalid name for a sheet: '{}'.", new_name));
+            return Err(format!("Invalid name for a sheet: '{new_name}'."));
         }
         if self.get_sheet_index_by_name(new_name).is_some() {
-            return Err(format!("Sheet already exists: '{}'.", new_name));
+            return Err(format!("Sheet already exists: '{new_name}'."));
         }
         // Gets the new name and checks that a sheet with that index exists
         let old_name = self.workbook.worksheet(sheet_index)?.get_name();
@@ -362,14 +362,14 @@ impl Model {
         };
         let locale = match get_locale(locale_id) {
             Ok(l) => l.clone(),
-            Err(_) => return Err(format!("Invalid locale: {}", locale_id)),
+            Err(_) => return Err(format!("Invalid locale: {locale_id}")),
         };
 
         let milliseconds = get_milliseconds_since_epoch();
         let seconds = milliseconds / 1000;
         let dt = match DateTime::from_timestamp(seconds, 0) {
             Some(s) => s,
-            None => return Err(format!("Invalid timestamp: {}", milliseconds)),
+            None => return Err(format!("Invalid timestamp: {milliseconds}")),
         };
         // "2020-08-06T21:20:53Z
         let now = dt.format("%Y-%m-%dT%H:%M:%SZ").to_string();

base/src/number_format.rs

@@ -112,29 +112,36 @@ pub fn to_precision(value: f64, precision: usize) -> f64 {
 /// ```
 /// This intends to be equivalent to the js: `${parseFloat(value.toPrecision(precision)})`
 /// See ([ecma](https://tc39.es/ecma262/#sec-number.prototype.toprecision)).
-/// FIXME: There has to be a better algorithm :/
 pub fn to_excel_precision_str(value: f64) -> String {
     to_precision_str(value, 15)
 }
+
+pub fn to_excel_precision(value: f64, precision: usize) -> f64 {
+    if !value.is_finite() {
+        return value;
+    }
+
+    let s = format!("{:.*e}", precision.saturating_sub(1), value);
+    s.parse::<f64>().unwrap_or(value)
+}
+
 pub fn to_precision_str(value: f64, precision: usize) -> String {
+    if !value.is_finite() {
         if value.is_infinite() {
             return "inf".to_string();
-    }
+        } else {
-    if value.is_nan() {
             return "NaN".to_string();
         }
-    let exponent = value.abs().log10().floor();
+    }
-    let base = value / 10.0_f64.powf(exponent);
+
-    let base = format!("{0:.1$}", base, precision - 1);
+    let s = format!("{:.*e}", precision.saturating_sub(1), value);
-    let value = format!("{}e{}", base, exponent).parse::<f64>().unwrap_or({
+    let parsed = s.parse::<f64>().unwrap_or(value);
-        // TODO: do this in a way that does not require a possible error
+
-        0.0
-    });
     // I would love to use the std library. There is not a speed concern here
     // problem is it doesn't do the right thing
     // Also ryu is my favorite _modern_ algorithm
     let mut buffer = ryu::Buffer::new();
-    let text = buffer.format(value);
+    let text = buffer.format(parsed);
     // The above algorithm converts 2 to 2.0 regrettably
     if let Some(stripped) = text.strip_suffix(".0") {
         return stripped.to_string();

base/src/styles.rs

@@ -154,7 +154,7 @@ impl Styles {
                 return Ok(cell_style.xf_id);
             }
         }
-        Err(format!("Style '{}' not found", style_name))
+        Err(format!("Style '{style_name}' not found"))
     }
 
     pub fn create_named_style(&mut self, style_name: &str, style: &Style) -> Result<(), String> {

base/src/test/engineering/test_complex.rs

@@ -133,6 +133,7 @@ fn fn_imcot() {
     );
 }
 
+#[cfg_attr(target_os = "windows", ignore)]
 #[test]
 fn fn_imtan() {
     let mut model = new_empty_model();

base/src/test/mod.rs

@@ -7,6 +7,9 @@ mod test_column_width;
 mod test_criteria;
 mod test_currency;
 mod test_date_and_time;
+mod test_datedif_leap_month_end;
+mod test_days360_month_end;
+mod test_degrees_radians;
 mod test_error_propagation;
 mod test_fn_average;
 mod test_fn_averageifs;
@@ -27,6 +30,7 @@ mod test_fn_sum;
 mod test_fn_sumifs;
 mod test_fn_textbefore;
 mod test_fn_textjoin;
+mod test_fn_time;
 mod test_fn_unicode;
 mod test_frozen_rows_columns;
 mod test_general;
@@ -43,8 +47,11 @@ mod test_sheets;
 mod test_styles;
 mod test_trigonometric;
 mod test_true_false;
+mod test_weekday_return_types;
+mod test_weeknum_return_types;
 mod test_workbook;
 mod test_worksheet;
+mod test_yearfrac_basis;
 pub(crate) mod util;
 
 mod engineering;
@@ -55,14 +62,23 @@ mod test_arrays;
 mod test_escape_quotes;
 mod test_extend;
 mod test_fn_fv;
+mod test_fn_round;
 mod test_fn_type;
 mod test_frozen_rows_and_columns;
 mod test_geomean;
 mod test_get_cell_content;
 mod test_implicit_intersection;
 mod test_issue_155;
+mod test_issue_483;
+mod test_ln;
+mod test_log;
+mod test_log10;
+mod test_mod_quotient;
+mod test_networkdays;
+mod test_now;
 mod test_percentage;
 mod test_set_functions_error_handling;
+mod test_sheet_names;
 mod test_today;
 mod test_types;
 mod user_model;

base/src/test/test_actions.rs

@@ -1,6 +1,6 @@
 #![allow(clippy::unwrap_used)]
 
-use crate::constants::{DEFAULT_ROW_HEIGHT, LAST_COLUMN};
+use crate::constants::{DEFAULT_ROW_HEIGHT, LAST_COLUMN, LAST_ROW};
 use crate::model::Model;
 use crate::test::util::new_empty_model;
 use crate::types::Col;
@@ -508,6 +508,10 @@ fn test_move_column_right() {
     assert_eq!(model._get_formula("E5"), "=SUM(H3:J7)");
     assert_eq!(model._get_formula("E6"), "=SUM(H3:H7)");
     assert_eq!(model._get_formula("E7"), "=SUM(G3:G7)");
+
+    // Data moved as well
+    assert_eq!(model._get_text("G1"), "1");
+    assert_eq!(model._get_text("H1"), "3");
 }
 
 #[test]
@@ -532,5 +536,249 @@ fn tets_move_column_error() {
     assert!(result.is_ok());
 }
 
+#[test]
+fn test_move_row_down() {
+    let mut model = new_empty_model();
+    populate_table(&mut model);
+    // Formulas referencing rows 3 and 4
+    model._set("E3", "=G3");
+    model._set("E4", "=G4");
+    model._set("E5", "=SUM(G3:J3)");
+    model._set("E6", "=SUM(G3:G3)");
+    model._set("E7", "=SUM(G4:G4)");
+    model.evaluate();
+
+    // Move row 3 down by one position
+    let result = model.move_row_action(0, 3, 1);
+    assert!(result.is_ok());
+    model.evaluate();
+
+    assert_eq!(model._get_formula("E3"), "=G3");
+    assert_eq!(model._get_formula("E4"), "=G4");
+    assert_eq!(model._get_formula("E5"), "=SUM(G4:J4)");
+    assert_eq!(model._get_formula("E6"), "=SUM(G4:G4)");
+    assert_eq!(model._get_formula("E7"), "=SUM(G3:G3)");
+
+    // Data moved as well
+    assert_eq!(model._get_text("G4"), "-2");
+    assert_eq!(model._get_text("G3"), "");
+}
+
+#[test]
+fn test_move_row_up() {
+    let mut model = new_empty_model();
+    populate_table(&mut model);
+    // Formulas referencing rows 4 and 5
+    model._set("E4", "=G4");
+    model._set("E5", "=G5");
+    model._set("E6", "=SUM(G4:J4)");
+    model._set("E7", "=SUM(G4:G4)");
+    model._set("E8", "=SUM(G5:G5)");
+    model.evaluate();
+
+    // Move row 5 up by one position
+    let result = model.move_row_action(0, 5, -1);
+    assert!(result.is_ok());
+    model.evaluate();
+
+    assert_eq!(model._get_formula("E4"), "=G4");
+    assert_eq!(model._get_formula("E5"), "=G5");
+    assert_eq!(model._get_formula("E6"), "=SUM(G5:J5)");
+    assert_eq!(model._get_formula("E7"), "=SUM(G5:G5)");
+    assert_eq!(model._get_formula("E8"), "=SUM(G4:G4)");
+
+    // Data moved as well
+    assert_eq!(model._get_text("G4"), "");
+    assert_eq!(model._get_text("G5"), "");
+}
+
+#[test]
+fn test_move_row_error() {
+    let mut model = new_empty_model();
+    model.evaluate();
+
+    let result = model.move_row_action(0, 7, -10);
+    assert!(result.is_err());
+
+    let result = model.move_row_action(0, -7, 20);
+    assert!(result.is_err());
+
+    let result = model.move_row_action(0, LAST_ROW, 1);
+    assert!(result.is_err());
+
+    let result = model.move_row_action(0, LAST_ROW + 1, -10);
+    assert!(result.is_err());
+
+    // This works
+    let result = model.move_row_action(0, LAST_ROW, -1);
+    assert!(result.is_ok());
+}
+
+#[test]
+fn test_move_row_down_absolute_refs() {
+    let mut model = new_empty_model();
+    populate_table(&mut model);
+    // Absolute references
+    model._set("E3", "=$G$3");
+    model._set("E4", "=$G$4");
+    model._set("E5", "=SUM($G$3:$J$3)");
+    model._set("E6", "=SUM($G$3:$G$3)");
+    model._set("E7", "=SUM($G$4:$G$4)");
+    model.evaluate();
+
+    assert!(model.move_row_action(0, 3, 1).is_ok());
+    model.evaluate();
+
+    assert_eq!(model._get_formula("E3"), "=$G$3");
+    assert_eq!(model._get_formula("E4"), "=$G$4");
+    assert_eq!(model._get_formula("E5"), "=SUM($G$4:$J$4)");
+    assert_eq!(model._get_formula("E6"), "=SUM($G$4:$G$4)");
+    assert_eq!(model._get_formula("E7"), "=SUM($G$3:$G$3)");
+}
+
+#[test]
+fn test_move_column_right_absolute_refs() {
+    let mut model = new_empty_model();
+    populate_table(&mut model);
+    // Absolute references
+    model._set("E3", "=$G$3");
+    model._set("E4", "=$H$3");
+    model._set("E5", "=SUM($G$3:$J$7)");
+    model._set("E6", "=SUM($G$3:$G$7)");
+    model._set("E7", "=SUM($H$3:$H$7)");
+    model.evaluate();
+
+    assert!(model.move_column_action(0, 7, 1).is_ok());
+    model.evaluate();
+
+    assert_eq!(model._get_formula("E3"), "=$H$3");
+    assert_eq!(model._get_formula("E4"), "=$G$3");
+    assert_eq!(model._get_formula("E5"), "=SUM($H$3:$J$7)");
+    assert_eq!(model._get_formula("E6"), "=SUM($H$3:$H$7)");
+    assert_eq!(model._get_formula("E7"), "=SUM($G$3:$G$7)");
+}
+
+#[test]
+fn test_move_row_down_mixed_refs() {
+    let mut model = new_empty_model();
+    populate_table(&mut model);
+    model._set("E3", "=$G3"); // absolute col, relative row
+    model._set("E4", "=$G4");
+    model._set("E5", "=SUM($G3:$J3)");
+    model._set("E6", "=SUM($G3:$G3)");
+    model._set("E7", "=SUM($G4:$G4)");
+    model._set("F3", "=H$3"); // relative col, absolute row
+    model._set("F4", "=G$3");
+    model.evaluate();
+
+    assert!(model.move_row_action(0, 3, 1).is_ok());
+    model.evaluate();
+
+    assert_eq!(model._get_formula("E3"), "=$G3");
+    assert_eq!(model._get_formula("E4"), "=$G4");
+    assert_eq!(model._get_formula("E5"), "=SUM($G4:$J4)");
+    assert_eq!(model._get_formula("E6"), "=SUM($G4:$G4)");
+    assert_eq!(model._get_formula("E7"), "=SUM($G3:$G3)");
+    assert_eq!(model._get_formula("F3"), "=G$4");
+    assert_eq!(model._get_formula("F4"), "=H$4");
+}
+
+#[test]
+fn test_move_column_right_mixed_refs() {
+    let mut model = new_empty_model();
+    populate_table(&mut model);
+    model._set("E3", "=$G3");
+    model._set("E4", "=$H3");
+    model._set("E5", "=SUM($G3:$J7)");
+    model._set("E6", "=SUM($G3:$G7)");
+    model._set("E7", "=SUM($H3:$H7)");
+    model._set("F3", "=H$3");
+    model._set("F4", "=H$3");
+    model.evaluate();
+
+    assert!(model.move_column_action(0, 7, 1).is_ok());
+    model.evaluate();
+
+    assert_eq!(model._get_formula("E3"), "=$H3");
+    assert_eq!(model._get_formula("E4"), "=$G3");
+    assert_eq!(model._get_formula("E5"), "=SUM($H3:$J7)");
+    assert_eq!(model._get_formula("E6"), "=SUM($H3:$H7)");
+    assert_eq!(model._get_formula("E7"), "=SUM($G3:$G7)");
+    assert_eq!(model._get_formula("F3"), "=G$3");
+    assert_eq!(model._get_formula("F4"), "=G$3");
+}
+
+#[test]
+fn test_move_row_height() {
+    let mut model = new_empty_model();
+    let sheet = 0;
+    let custom_height = DEFAULT_ROW_HEIGHT * 2.0;
+    // Set a custom height for row 3
+    model
+        .workbook
+        .worksheet_mut(sheet)
+        .unwrap()
+        .set_row_height(3, custom_height)
+        .unwrap();
+
+    // Record the original height of row 4 (should be the default)
+    let original_row4_height = model.get_row_height(sheet, 4).unwrap();
+
+    // Move row 3 down by one position
+    assert!(model.move_row_action(sheet, 3, 1).is_ok());
+
+    // The custom height should now be on row 4
+    assert_eq!(model.get_row_height(sheet, 4), Ok(custom_height));
+
+    // Row 3 should now have the previous height of row 4
+    assert_eq!(model.get_row_height(sheet, 3), Ok(original_row4_height));
+}
+
+/// Moving a row down by two positions should shift formulas on intermediate
+/// rows by only one (the row that gets skipped), not by the full delta ‒ this
+/// guards against the regression fixed in the RowMove displacement logic.
+#[test]
+fn test_row_move_down_two_updates_intermediate_refs_by_one() {
+    let mut model = new_empty_model();
+    populate_table(&mut model);
+    // Set up formulas to verify intermediate rows shift by 1 (not full delta).
+    model._set("E3", "=G3"); // target row
+    model._set("E4", "=G4"); // intermediate row
+    model._set("E5", "=SUM(G3:J3)");
+    model.evaluate();
+
+    // Move row 3 down by two positions (row 3 -> row 5)
+    assert!(model.move_row_action(0, 3, 2).is_ok());
+    model.evaluate();
+
+    // Assert that references for the moved row and intermediate row are correct.
+    assert_eq!(model._get_formula("E3"), "=G3");
+    assert_eq!(model._get_formula("E5"), "=G5");
+    assert_eq!(model._get_formula("E4"), "=SUM(G5:J5)");
+}
+
+/// Moving a column right by two positions should shift formulas on
+/// intermediate columns by only one, ensuring the ColumnMove displacement
+/// logic handles multi-position moves correctly.
+#[test]
+fn test_column_move_right_two_updates_intermediate_refs_by_one() {
+    let mut model = new_empty_model();
+    populate_table(&mut model);
+    // Set up formulas to verify intermediate columns shift by 1 (not full delta).
+    model._set("E3", "=$G3"); // target column
+    model._set("E4", "=$H3"); // intermediate column
+    model._set("E5", "=SUM($G3:$J7)");
+    model.evaluate();
+
+    // Move column G (7) right by two positions (G -> I)
+    assert!(model.move_column_action(0, 7, 2).is_ok());
+    model.evaluate();
+
+    // Assert that references for moved and intermediate columns are correct.
+    assert_eq!(model._get_formula("E3"), "=$I3");
+    assert_eq!(model._get_formula("E4"), "=$G3");
+    assert_eq!(model._get_formula("E5"), "=SUM($I3:$J7)");
+}
+
 // A  B  C  D  E  F  G   H  I  J   K   L   M   N   O   P   Q   R
 // 1  2  3  4  5  6  7   8  9  10  11  12  13  14  15  16  17  18

base/src/test/test_arabic_roman

@@ -0,0 +1,27 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=ARABIC()");
+    model._set("A2", "=ARABIC(V)");
+    model._set("A3", "=ARABIC(V, 2)");
+
+    model._set("A4", "=ROMAN()");
+    model._set("A5", "=ROMAN(5)");
+    model._set("A6", "=ROMAN(5, 0)");
+    model._set("A7", "=ROMAN(5, 0, 2)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"5");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+    assert_eq!(model._get_text("A5"), *"V");
+    assert_eq!(model._get_text("A6"), *"V");
+    assert_eq!(model._get_text("A7"), *"#ERROR!");
+}

base/src/test/test_combin_combina

@@ -0,0 +1,27 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=COMBIN(5,2)");
+    model._set("A2", "=COMBINA(5,2)");
+    model._set("A3", "=COMBIN()");
+    model._set("A4", "=COMBINA()");
+    model._set("A5", "=COMBIN(2)");
+    model._set("A6", "=COMBINA(2)");
+    model._set("A5", "=COMBIN(1, 2, 3)");
+    model._set("A6", "=COMBINA(1, 2, 3)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"10");
+    assert_eq!(model._get_text("A2"), *"15");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+    assert_eq!(model._get_text("A7"), *"#ERROR!");
+    assert_eq!(model._get_text("A8"), *"#ERROR!");
+}

base/src/test/test_date_and_time.rs

@@ -6,6 +6,11 @@
 /// We can also enter examples that illustrate/document a part of the function
 use crate::{cell::CellValue, test::util::new_empty_model};
 
+// Excel uses a serial date system where Jan 1, 1900 = 1 (though it treats 1900 as a leap year)
+// Most test dates are documented inline, but we define boundary values here:
+const EXCEL_MAX_DATE: f64 = 2958465.0; // Dec 31, 9999 - used in boundary tests
+const EXCEL_INVALID_DATE: f64 = 2958466.0; // One day past max - used in error tests
+
 #[test]
 fn test_fn_date_arguments() {
     let mut model = new_empty_model();
@@ -216,3 +221,380 @@ fn test_date_early_dates() {
         Ok(CellValue::Number(61.0))
     );
 }
+#[test]
+fn test_days_function() {
+    let mut model = new_empty_model();
+
+    // Basic functionality
+    model._set("A1", "=DAYS(44570,44561)");
+    model._set("A2", "=DAYS(44561,44570)"); // Reversed order
+    model._set("A3", "=DAYS(44561,44561)");
+
+    // Edge cases
+    model._set("A4", "=DAYS(1,2)"); // Early dates
+    model._set(
+        "A5",
+        &format!("=DAYS({},{})", EXCEL_MAX_DATE, EXCEL_MAX_DATE - 1.0),
+    ); // Near max date
+
+    // Error cases - wrong argument count
+    model._set("A6", "=DAYS()");
+    model._set("A7", "=DAYS(44561)");
+    model._set("A8", "=DAYS(44561,44570,1)");
+
+    // Error cases - invalid dates
+    model._set("A9", "=DAYS(-1,44561)");
+    model._set("A10", &format!("=DAYS(44561,{EXCEL_INVALID_DATE})"));
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"9");
+    assert_eq!(model._get_text("A2"), *"-9");
+    assert_eq!(model._get_text("A3"), *"0");
+    assert_eq!(model._get_text("A4"), *"-1"); // DAYS(1,2) = 1-2 = -1
+    assert_eq!(model._get_text("A5"), *"1");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+    assert_eq!(model._get_text("A7"), *"#ERROR!");
+    assert_eq!(model._get_text("A8"), *"#ERROR!");
+    assert_eq!(model._get_text("A9"), *"#NUM!");
+    assert_eq!(model._get_text("A10"), *"#NUM!");
+}
+
+#[test]
+fn test_days360_function() {
+    let mut model = new_empty_model();
+
+    // Basic functionality with different basis values
+    model._set("A1", "=DAYS360(44196,44560)"); // Default basis (US 30/360)
+    model._set("A2", "=DAYS360(44196,44560,FALSE)"); // US 30/360 explicitly
+    model._set("A3", "=DAYS360(44196,44560,TRUE)"); // European 30/360
+
+    // Same date
+    model._set("A4", "=DAYS360(44561,44561)");
+    model._set("A5", "=DAYS360(44561,44561,TRUE)");
+
+    // Reverse order (negative result)
+    model._set("A6", "=DAYS360(44560,44196)");
+    model._set("A7", "=DAYS360(44560,44196,TRUE)");
+
+    // Edge cases
+    model._set("A8", "=DAYS360(1,2)");
+    model._set("A9", "=DAYS360(1,2,FALSE)");
+
+    // Error cases - wrong argument count
+    model._set("A10", "=DAYS360()");
+    model._set("A11", "=DAYS360(44561)");
+    model._set("A12", "=DAYS360(44561,44570,TRUE,1)");
+
+    // Error cases - invalid dates
+    model._set("A13", "=DAYS360(-1,44561)");
+    model._set("A14", &format!("=DAYS360(44561,{EXCEL_INVALID_DATE})"));
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"360");
+    assert_eq!(model._get_text("A2"), *"360");
+    assert_eq!(model._get_text("A3"), *"360");
+    assert_eq!(model._get_text("A4"), *"0");
+    assert_eq!(model._get_text("A5"), *"0");
+    assert_eq!(model._get_text("A6"), *"-360");
+    assert_eq!(model._get_text("A7"), *"-360");
+    assert_eq!(model._get_text("A8"), *"1");
+    assert_eq!(model._get_text("A9"), *"1");
+    assert_eq!(model._get_text("A10"), *"#ERROR!");
+    assert_eq!(model._get_text("A11"), *"#ERROR!");
+    assert_eq!(model._get_text("A12"), *"#ERROR!");
+    assert_eq!(model._get_text("A13"), *"#NUM!");
+    assert_eq!(model._get_text("A14"), *"#NUM!");
+}
+
+#[test]
+fn test_weekday_function() {
+    let mut model = new_empty_model();
+
+    // Test return_type parameter variations with one known date (Friday 44561)
+    model._set("A1", "=WEEKDAY(44561)"); // Default: Sun=1, Fri=6
+    model._set("A2", "=WEEKDAY(44561,2)"); // Mon=1, Fri=5
+    model._set("A3", "=WEEKDAY(44561,3)"); // Mon=0, Fri=4
+
+    // Test boundary days (Sun/Mon) to verify return_type logic
+    model._set("A4", "=WEEKDAY(44556,1)"); // Sunday: should be 1
+    model._set("A5", "=WEEKDAY(44556,2)"); // Sunday: should be 7
+    model._set("A6", "=WEEKDAY(44557,2)"); // Monday: should be 1
+
+    // Error cases
+    model._set("A7", "=WEEKDAY()"); // Wrong arg count
+    model._set("A8", "=WEEKDAY(44561,0)"); // Invalid return_type
+    model._set("A9", "=WEEKDAY(-1)"); // Invalid date
+
+    model.evaluate();
+
+    // Core functionality
+    assert_eq!(model._get_text("A1"), *"6"); // Friday default
+    assert_eq!(model._get_text("A2"), *"5"); // Friday Mon=1
+    assert_eq!(model._get_text("A3"), *"4"); // Friday Mon=0
+
+    // Boundary verification
+    assert_eq!(model._get_text("A4"), *"1"); // Sunday Sun=1
+    assert_eq!(model._get_text("A5"), *"7"); // Sunday Mon=1
+    assert_eq!(model._get_text("A6"), *"1"); // Monday Mon=1
+
+    // Error cases
+    assert_eq!(model._get_text("A7"), *"#ERROR!");
+    assert_eq!(model._get_text("A8"), *"#VALUE!");
+    assert_eq!(model._get_text("A9"), *"#NUM!");
+}
+
+#[test]
+fn test_weeknum_function() {
+    let mut model = new_empty_model();
+
+    // Test different return_type values (1=week starts Sunday, 2=week starts Monday)
+    model._set("A1", "=WEEKNUM(44561)"); // Default return_type=1
+    model._set("A2", "=WEEKNUM(44561,1)"); // Sunday start
+    model._set("A3", "=WEEKNUM(44561,2)"); // Monday start
+
+    // Test year boundaries
+    model._set("A4", "=WEEKNUM(43831,1)"); // Jan 1, 2020 (Wednesday)
+    model._set("A5", "=WEEKNUM(43831,2)"); // Jan 1, 2020 (Wednesday)
+    model._set("A6", "=WEEKNUM(44196,1)"); // Dec 31, 2020 (Thursday)
+    model._set("A7", "=WEEKNUM(44196,2)"); // Dec 31, 2020 (Thursday)
+
+    // Test first and last weeks of year
+    model._set("A8", "=WEEKNUM(44197,1)"); // Jan 1, 2021 (Friday)
+    model._set("A9", "=WEEKNUM(44197,2)"); // Jan 1, 2021 (Friday)
+    model._set("A10", "=WEEKNUM(44561,1)"); // Dec 31, 2021 (Friday)
+    model._set("A11", "=WEEKNUM(44561,2)"); // Dec 31, 2021 (Friday)
+
+    // Error cases - wrong argument count
+    model._set("A12", "=WEEKNUM()");
+    model._set("A13", "=WEEKNUM(44561,1,1)");
+
+    // Error cases - invalid return_type
+    model._set("A14", "=WEEKNUM(44561,0)");
+    model._set("A15", "=WEEKNUM(44561,3)");
+    model._set("A16", "=WEEKNUM(44561,-1)");
+
+    // Error cases - invalid dates
+    model._set("A17", "=WEEKNUM(-1)");
+    model._set("A18", &format!("=WEEKNUM({EXCEL_INVALID_DATE})"));
+
+    model.evaluate();
+
+    // Basic functionality
+    assert_eq!(model._get_text("A1"), *"53"); // Week 53
+    assert_eq!(model._get_text("A2"), *"53"); // Week 53 (Sunday start)
+    assert_eq!(model._get_text("A3"), *"53"); // Week 53 (Monday start)
+
+    // Year boundary tests
+    assert_eq!(model._get_text("A4"), *"1"); // Jan 1, 2020 (Sunday start)
+    assert_eq!(model._get_text("A5"), *"1"); // Jan 1, 2020 (Monday start)
+    assert_eq!(model._get_text("A6"), *"53"); // Dec 31, 2020 (Sunday start)
+    assert_eq!(model._get_text("A7"), *"53"); // Dec 31, 2020 (Monday start)
+
+    // 2021 tests
+    assert_eq!(model._get_text("A8"), *"1"); // Jan 1, 2021 (Sunday start)
+    assert_eq!(model._get_text("A9"), *"1"); // Jan 1, 2021 (Monday start)
+    assert_eq!(model._get_text("A10"), *"53"); // Dec 31, 2021 (Sunday start)
+    assert_eq!(model._get_text("A11"), *"53"); // Dec 31, 2021 (Monday start)
+
+    // Error cases
+    assert_eq!(model._get_text("A12"), *"#ERROR!");
+    assert_eq!(model._get_text("A13"), *"#ERROR!");
+    assert_eq!(model._get_text("A14"), *"#VALUE!");
+    assert_eq!(model._get_text("A15"), *"#VALUE!");
+    assert_eq!(model._get_text("A16"), *"#VALUE!");
+    assert_eq!(model._get_text("A17"), *"#NUM!");
+    assert_eq!(model._get_text("A18"), *"#NUM!");
+}
+
+#[test]
+fn test_workday_function() {
+    let mut model = new_empty_model();
+
+    // Basic functionality
+    model._set("A1", "=WORKDAY(44560,1)");
+    model._set("A2", "=WORKDAY(44561,-1)");
+    model._set("A3", "=WORKDAY(44561,0)");
+    model._set("A4", "=WORKDAY(44560,5)");
+
+    // Test with holidays
+    model._set("B1", "44561");
+    model._set("A5", "=WORKDAY(44560,1,B1)"); // Should skip the holiday
+    model._set("B2", "44562");
+    model._set("B3", "44563");
+    model._set("A6", "=WORKDAY(44560,3,B1:B3)"); // Multiple holidays
+
+    // Test starting on weekend
+    model._set("A7", "=WORKDAY(44562,1)"); // Saturday start
+    model._set("A8", "=WORKDAY(44563,1)"); // Sunday start
+
+    // Test negative workdays
+    model._set("A9", "=WORKDAY(44565,-3)"); // Go backwards 3 days
+    model._set("A10", "=WORKDAY(44565,-5,B1:B3)"); // Backwards with holidays
+
+    // Edge cases
+    model._set("A11", "=WORKDAY(1,1)"); // Early date
+    model._set("A12", "=WORKDAY(100000,10)"); // Large numbers
+
+    // Error cases - wrong argument count
+    model._set("A13", "=WORKDAY()");
+    model._set("A14", "=WORKDAY(44560)");
+    model._set("A15", "=WORKDAY(44560,1,B1,B2)");
+
+    // Error cases - invalid dates
+    model._set("A16", "=WORKDAY(-1,1)");
+    model._set("A17", &format!("=WORKDAY({EXCEL_INVALID_DATE},1)"));
+
+    // Error cases - invalid holiday dates
+    model._set("B4", "-1");
+    model._set("A18", "=WORKDAY(44560,1,B4)");
+
+    model.evaluate();
+
+    // Basic functionality
+    assert_eq!(model._get_text("A1"), *"44561"); // 1 day forward
+    assert_eq!(model._get_text("A2"), *"44560"); // 1 day backward
+    assert_eq!(model._get_text("A3"), *"44561"); // 0 days
+    assert_eq!(model._get_text("A4"), *"44567"); // 5 days forward
+
+    // With holidays
+    assert_eq!(model._get_text("A5"), *"44564"); // Skip holiday, go to Monday
+    assert_eq!(model._get_text("A6"), *"44566"); // Skip multiple holidays
+
+    // Weekend starts
+    assert_eq!(model._get_text("A7"), *"44564"); // From Saturday
+    assert_eq!(model._get_text("A8"), *"44564"); // From Sunday
+
+    // Negative workdays
+    assert_eq!(model._get_text("A9"), *"44560"); // 3 days back
+    assert_eq!(model._get_text("A10"), *"44557"); // 5 days back with holidays
+
+    // Edge cases
+    assert_eq!(model._get_text("A11"), *"2"); // Early date
+    assert_eq!(model._get_text("A12"), *"100014"); // Large numbers
+
+    // Error cases
+    assert_eq!(model._get_text("A13"), *"#ERROR!");
+    assert_eq!(model._get_text("A14"), *"#ERROR!");
+    assert_eq!(model._get_text("A15"), *"#ERROR!");
+    assert_eq!(model._get_text("A16"), *"#NUM!");
+    assert_eq!(model._get_text("A17"), *"#NUM!");
+    assert_eq!(model._get_text("A18"), *"#NUM!"); // Invalid holiday
+}
+
+#[test]
+fn test_workday_intl_function() {
+    let mut model = new_empty_model();
+
+    // Test key weekend mask types
+    model._set("A1", "=WORKDAY.INTL(44560,1,1)"); // Numeric: standard (Sat-Sun)
+    model._set("A2", "=WORKDAY.INTL(44560,1,2)"); // Numeric: Sun-Mon
+    model._set("A3", "=WORKDAY.INTL(44560,1,\"0000001\")"); // String: Sunday only
+    model._set("A4", "=WORKDAY.INTL(44560,1,\"1100000\")"); // String: Mon-Tue
+
+    // Test with holidays
+    model._set("B1", "44561");
+    model._set("A5", "=WORKDAY.INTL(44560,2,1,B1)"); // Standard + holiday
+    model._set("A6", "=WORKDAY.INTL(44560,2,7,B1)"); // Fri-Sat + holiday
+
+    // Basic edge cases
+    model._set("A7", "=WORKDAY.INTL(44561,0,1)"); // Zero days
+    model._set("A8", "=WORKDAY.INTL(44565,-1,1)"); // Negative days
+
+    // Error cases
+    model._set("A9", "=WORKDAY.INTL()"); // Wrong arg count
+    model._set("A10", "=WORKDAY.INTL(44560,1,0)"); // Invalid weekend mask
+    model._set("A11", "=WORKDAY.INTL(44560,1,\"123\")"); // Invalid string mask
+    model._set("A12", "=WORKDAY.INTL(-1,1,1)"); // Invalid date
+
+    model.evaluate();
+
+    // Weekend mask functionality
+    assert_eq!(model._get_text("A1"), *"44561"); // Standard weekend
+    assert_eq!(model._get_text("A2"), *"44561"); // Sun-Mon weekend
+    assert_eq!(model._get_text("A3"), *"44561"); // Sunday only
+    assert_eq!(model._get_text("A4"), *"44561"); // Mon-Tue weekend
+
+    // With holidays
+    assert_eq!(model._get_text("A5"), *"44565"); // Skip holiday + standard weekend
+    assert_eq!(model._get_text("A6"), *"44564"); // Skip holiday + Fri-Sat weekend
+
+    // Edge cases
+    assert_eq!(model._get_text("A7"), *"44561"); // Zero days
+    assert_eq!(model._get_text("A8"), *"44564"); // Negative days
+
+    // Error cases
+    assert_eq!(model._get_text("A9"), *"#ERROR!");
+    assert_eq!(model._get_text("A10"), *"#NUM!");
+    assert_eq!(model._get_text("A11"), *"#VALUE!");
+    assert_eq!(model._get_text("A12"), *"#NUM!");
+}
+
+#[test]
+fn test_yearfrac_function() {
+    let mut model = new_empty_model();
+
+    // Test key basis values (not exhaustive - just verify parameter works)
+    model._set("A1", "=YEARFRAC(44561,44926)"); // Default (30/360)
+    model._set("A2", "=YEARFRAC(44561,44926,1)"); // Actual/actual
+    model._set("A3", "=YEARFRAC(44561,44926,4)"); // European 30/360
+
+    // Edge cases
+    model._set("A4", "=YEARFRAC(44561,44561,1)"); // Same date = 0
+    model._set("A6", "=YEARFRAC(44197,44562,1)"); // Exact year (2021)
+
+    // Error cases
+    model._set("A7", "=YEARFRAC()"); // Wrong arg count
+    model._set("A8", "=YEARFRAC(44561,44926,5)"); // Invalid basis
+    model._set("A9", "=YEARFRAC(-1,44926,1)"); // Invalid date
+
+    model.evaluate();
+
+    // Basic functionality (approximate values expected)
+    assert_eq!(model._get_text("A1"), *"1"); // About 1 year
+    assert_eq!(model._get_text("A2"), *"1"); // About 1 year
+    assert_eq!(model._get_text("A3"), *"1"); // About 1 year
+
+    // Edge cases
+    assert_eq!(model._get_text("A4"), *"0"); // Same date
+    assert_eq!(model._get_text("A6"), *"1"); // Exact year
+
+    // Error cases
+    assert_eq!(model._get_text("A7"), *"#ERROR!");
+    assert_eq!(model._get_text("A8"), *"#NUM!"); // Invalid basis should return #NUM!
+    assert_eq!(model._get_text("A9"), *"#NUM!");
+}
+
+#[test]
+fn test_isoweeknum_function() {
+    let mut model = new_empty_model();
+
+    // Basic functionality
+    model._set("A1", "=ISOWEEKNUM(44563)"); // Mid-week date
+    model._set("A2", "=ISOWEEKNUM(44561)"); // Year-end date
+
+    // Key ISO week boundaries (just critical cases)
+    model._set("A3", "=ISOWEEKNUM(44197)"); // Jan 1, 2021 (Fri) -> Week 53 of 2020
+    model._set("A4", "=ISOWEEKNUM(44200)"); // Jan 4, 2021 (Mon) -> Week 1 of 2021
+    model._set("A5", "=ISOWEEKNUM(44564)"); // Jan 3, 2022 (Mon) -> Week 1 of 2022
+
+    // Error cases
+    model._set("A6", "=ISOWEEKNUM()"); // Wrong arg count
+    model._set("A7", "=ISOWEEKNUM(-1)"); // Invalid date
+
+    model.evaluate();
+
+    // Basic functionality
+    assert_eq!(model._get_text("A1"), *"52");
+    assert_eq!(model._get_text("A2"), *"52");
+
+    // ISO week boundaries
+    assert_eq!(model._get_text("A3"), *"53"); // Week 53 of previous year
+    assert_eq!(model._get_text("A4"), *"1"); // Week 1 of current year
+    assert_eq!(model._get_text("A5"), *"1"); // Week 1 of next year
+
+    // Error cases
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+    assert_eq!(model._get_text("A7"), *"#NUM!");
+}

base/src/test/test_datedif_leap_month_end.rs

@@ -0,0 +1,33 @@
+use crate::test::util::new_empty_model;
+
+#[test]
+fn test_datedif_yd_leap_year_edge_cases() {
+    let mut model = new_empty_model();
+
+    // 29 Feb 2020 → 28 Feb 2021   (should be 0 days)
+    model._set("A1", "=DATEDIF(\"29/2/2020\", \"28/2/2021\", \"YD\")");
+
+    // 29 Feb 2020 → 1 Mar 2021    (should be 1 day)
+    model._set("A2", "=DATEDIF(\"29/2/2020\", \"2021-03-01\", \"YD\")");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"0");
+    assert_eq!(model._get_text("A2"), *"1");
+}
+
+#[test]
+fn test_datedif_md_month_end_edge_cases() {
+    let mut model = new_empty_model();
+
+    // 31 Jan 2021 → 28 Feb 2021 (non-leap) => 28
+    model._set("B1", "=DATEDIF(\"31/1/2021\", \"28/2/2021\", \"MD\")");
+
+    // 31 Jan 2020 → 29 Feb 2020 (leap) => 29
+    model._set("B2", "=DATEDIF(\"31/1/2020\", \"29/2/2020\", \"MD\")");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("B1"), *"28");
+    assert_eq!(model._get_text("B2"), *"29");
+}

base/src/test/test_days360_month_end.rs

@@ -0,0 +1,43 @@
+use crate::test::util::new_empty_model;
+
+#[test]
+fn test_days360_month_end_us() {
+    let mut model = new_empty_model();
+
+    // 31 Jan 2021 -> 28 Feb 2021 (non-leap)
+    model._set("A1", "=DAYS360(DATE(2021,1,31),DATE(2021,2,28))");
+
+    // 31 Jan 2020 -> 28 Feb 2020 (leap year – not last day of Feb)
+    model._set("A2", "=DAYS360(DATE(2020,1,31),DATE(2020,2,28))");
+
+    // 28 Feb 2020 -> 31 Mar 2020 (leap year span crossing month ends)
+    model._set("A3", "=DAYS360(DATE(2020,2,28),DATE(2020,3,31))");
+
+    // 30 Apr 2021 -> 31 May 2021 (end-of-month adjustment rule)
+    model._set("A4", "=DAYS360(DATE(2021,4,30),DATE(2021,5,31))");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"30");
+    assert_eq!(model._get_text("A2"), *"28");
+    assert_eq!(model._get_text("A3"), *"33");
+    assert_eq!(model._get_text("A4"), *"30");
+}
+
+#[test]
+fn test_days360_month_end_european() {
+    let mut model = new_empty_model();
+
+    // European basis = TRUE (or 1)
+    model._set("B1", "=DAYS360(DATE(2021,1,31),DATE(2021,2,28),TRUE)");
+
+    model._set("B2", "=DAYS360(DATE(2020,1,31),DATE(2020,2,29),TRUE)");
+
+    model._set("B3", "=DAYS360(DATE(2021,8,31),DATE(2021,9,30),TRUE)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("B1"), *"28");
+    assert_eq!(model._get_text("B2"), *"29");
+    assert_eq!(model._get_text("B3"), *"30");
+}

base/src/test/test_degrees_radians.rs

@@ -0,0 +1,22 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn fn_degrees_radians_arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=DEGREES()");
+    model._set("A2", "=RADIANS()");
+    model._set("A3", "=RADIANS(180)");
+    model._set("A4", "=RADIANS(180, 2)");
+    model._set("A5", "=DEGREES(RADIANS(180))");
+    model._set("A6", "=DEGREES(1, 2)");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"3.141592654");
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+    assert_eq!(model._get_text("A5"), *"180");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+}

base/src/test/test_even_odd

@@ -0,0 +1,23 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=EVEN(2)");
+    model._set("A2", "=ODD(2)");
+    model._set("A3", "=EVEN()");
+    model._set("A4", "=ODD()");
+    model._set("A5", "=EVEN(1, 2)");
+    model._set("A6", "=ODD(1, 2)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"2");
+    assert_eq!(model._get_text("A2"), *"3");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+}

base/src/test/test_exp_sign.rs

@@ -0,0 +1,26 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn fn_arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=EXP()");
+    model._set("A2", "=SIGN()");
+
+    model._set("A3", "=EXP(0)");
+    model._set("A4", "=SIGN(-10)");
+
+    model._set("A5", "=EXP(1, 2)");
+    model._set("A6", "=SIGN(1, 2)");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+
+    assert_eq!(model._get_text("A3"), *"1");
+    assert_eq!(model._get_text("A4"), *"-1");
+
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+}

base/src/test/test_fn_datevalue_datedif.rs

@@ -0,0 +1,182 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+use crate::types::Cell;
+
+// Helper to evaluate a formula and return the formatted text
+fn eval_formula(formula: &str) -> String {
+    let mut model = new_empty_model();
+    model._set("A1", formula);
+    model.evaluate();
+    model._get_text("A1")
+}
+
+// Helper that evaluates a formula and returns the raw value of A1 as a Result<f64, String>
+fn eval_formula_raw_number(formula: &str) -> Result<f64, String> {
+    let mut model = new_empty_model();
+    model._set("A1", formula);
+    model.evaluate();
+    match model._get_cell("A1") {
+        Cell::NumberCell { v, .. } => Ok(*v),
+        Cell::BooleanCell { v, .. } => Ok(if *v { 1.0 } else { 0.0 }),
+        Cell::ErrorCell { ei, .. } => Err(format!("{}", ei)),
+        _ => Err(model._get_text("A1")),
+    }
+}
+
+#[test]
+fn test_datevalue_basic_numeric() {
+    // DATEVALUE should return the serial number representing the date, **not** a formatted date
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"2/1/2023\")").unwrap(),
+        44958.0
+    );
+}
+
+#[test]
+fn test_datevalue_mmdd_with_leading_zero() {
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"02/01/2023\")").unwrap(),
+        44958.0
+    ); // 1-Feb-2023
+}
+
+#[test]
+fn test_datevalue_iso() {
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"2023-01-02\")").unwrap(),
+        44928.0
+    );
+}
+
+#[test]
+fn test_datevalue_month_name() {
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"2-Jan-23\")").unwrap(),
+        44928.0
+    );
+}
+
+#[test]
+fn test_datevalue_ambiguous_ddmm() {
+    // 01/02/2023 interpreted as MM/DD -> 2-Jan-2023
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"01/02/2023\")").unwrap(),
+        44929.0
+    );
+}
+
+#[test]
+fn test_datevalue_ddmm_unambiguous() {
+    // 15/01/2023 should be 15-Jan-2023 since 15 cannot be month
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"15/01/2023\")").unwrap(),
+        44941.0
+    );
+}
+
+#[test]
+fn test_datevalue_leap_day() {
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"29/02/2020\")").unwrap(),
+        43890.0
+    );
+}
+
+#[test]
+fn test_datevalue_year_first_text_month() {
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"2023/Jan/15\")").unwrap(),
+        44941.0
+    );
+}
+
+#[test]
+fn test_datevalue_mmdd_with_day_gt_12() {
+    assert_eq!(
+        eval_formula_raw_number("=DATEVALUE(\"6/15/2021\")").unwrap(),
+        44373.0
+    );
+}
+
+#[test]
+fn test_datevalue_error_conditions() {
+    let cases = [
+        "=DATEVALUE(\"31/04/2023\")",   // invalid day (Apr has 30 days)
+        "=DATEVALUE(\"13/13/2023\")",   // invalid month
+        "=DATEVALUE(\"not a date\")",   // non-date text
+    ];
+    for formula in cases {
+        let result = eval_formula(formula);
+        assert_eq!(result, *"#VALUE!", "Expected #VALUE! for {}", formula);
+    }
+}
+
+// Helper to set and evaluate a single DATEDIF call
+fn eval_datedif(unit: &str) -> String {
+    let mut model = new_empty_model();
+    let formula = format!("=DATEDIF(\"2020-01-01\", \"2021-06-15\", \"{}\")", unit);
+    model._set("A1", &formula);
+    model.evaluate();
+    model._get_text("A1")
+}
+
+#[test]
+fn test_datedif_y() {
+    assert_eq!(eval_datedif("Y"), *"1");
+}
+
+#[test]
+fn test_datedif_m() {
+    assert_eq!(eval_datedif("M"), *"17");
+}
+
+#[test]
+fn test_datedif_d() {
+    assert_eq!(eval_datedif("D"), *"531");
+}
+
+#[test]
+fn test_datedif_ym() {
+    assert_eq!(eval_datedif("YM"), *"5");
+}
+
+#[test]
+fn test_datedif_yd() {
+    assert_eq!(eval_datedif("YD"), *"165");
+}
+
+#[test]
+fn test_datedif_md() {
+    assert_eq!(eval_datedif("MD"), *"14");
+}
+
+#[test]
+fn test_datedif_edge_and_error_cases() {
+    let mut model = new_empty_model();
+    // Leap-year spanning
+    model._set("A1", "=DATEDIF(\"28/2/2020\", \"1/3/2020\", \"D\")");
+    // End date before start date => #NUM!
+    model._set("A2", "=DATEDIF(\"1/2/2021\", \"1/1/2021\", \"D\")");
+    // Invalid unit => #VALUE!
+    model._set("A3", "=DATEDIF(\"1/1/2020\", \"1/1/2021\", \"Z\")");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"2");
+    assert_eq!(model._get_text("A2"), *"#NUM!");
+    assert_eq!(model._get_text("A3"), *"#VALUE!");
+}
+
+#[test]
+fn test_datedif_mixed_case_unit() {
+    assert_eq!(eval_datedif("yD"), *"165"); // mixed-case should work
+}
+
+#[test]
+fn test_datedif_error_propagation() {
+    // Invalid date in arguments should propagate #VALUE!
+    let mut model = new_empty_model();
+    model._set("A1", "=DATEDIF(\"bad\", \"bad\", \"Y\")");
+    model.evaluate();
+    assert_eq!(model._get_text("A1"), *"#VALUE!");
+}

base/src/test/test_fn_datevalue_timevalue.rs

@@ -0,0 +1,24 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn datevalue_timevalue_arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=DATEVALUE()");
+    model._set("A2", "=TIMEVALUE()");
+    model._set("A3", "=DATEVALUE("2000-01-01")")
+    model._set("A4", "=TIMEVALUE("12:00:00")")
+    model._set("A5", "=DATEVALUE(1,2)");
+    model._set("A6", "=TIMEVALUE(1,2)");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"36526");
+    assert_eq!(model._get_text("A4"), *"0.5");
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+}
+
+

base/src/test/test_fn_or_xor.rs

@@ -174,7 +174,7 @@ fn fn_or_xor_no_arguments() {
         println!("Testing function: {func}");
 
         let mut model = new_empty_model();
-        model._set("A1", &format!("={}()", func));
+        model._set("A1", &format!("={func}()"));
         model.evaluate();
         assert_eq!(model._get_text("A1"), *"#ERROR!");
     }

base/src/test/test_fn_round.rs

@@ -0,0 +1,15 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn fn_round_approximation() {
+    let mut model = new_empty_model();
+    model._set("A1", "=ROUND(1.05*(0.0284+0.0046)-0.0284,4)");
+    model._set("A2", "=ROUNDDOWN(1.05*(0.0284+0.0046)-0.0284,5)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"0.0063");
+    assert_eq!(model._get_text("A2"), *"0.00625");
+}

base/src/test/test_fn_time.rs

@@ -0,0 +1,520 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+// Helper constants for common time values with detailed documentation
+const MIDNIGHT: &str = "0"; // 00:00:00 = 0/24 = 0
+const NOON: &str = "0.5"; // 12:00:00 = 12/24 = 0.5
+const TIME_14_30: &str = "0.604166667"; // 14:30:00 = 14.5/24 ≈ 0.604166667
+const TIME_14_30_45: &str = "0.6046875"; // 14:30:45 = 14.5125/24 = 0.6046875
+const TIME_14_30_59: &str = "0.604849537"; // 14:30:59 (from floored fractional inputs)
+const TIME_23_59_59: &str = "0.999988426"; // 23:59:59 = 23.99972.../24 ≈ 0.999988426
+
+// Excel documentation test values with explanations
+const TIME_2_24_AM: &str = "0.1"; // 2:24 AM = 2.4/24 = 0.1
+const TIME_2_PM: &str = "0.583333333"; // 2:00 PM = 14/24 ≈ 0.583333333
+const TIME_6_45_PM: &str = "0.78125"; // 6:45 PM = 18.75/24 = 0.78125
+const TIME_6_35_AM: &str = "0.274305556"; // 6:35 AM = 6.583333.../24 ≈ 0.274305556
+const TIME_2_30_AM: &str = "0.104166667"; // 2:30 AM = 2.5/24 ≈ 0.104166667
+const TIME_1_AM: &str = "0.041666667"; // 1:00 AM = 1/24 ≈ 0.041666667
+const TIME_9_PM: &str = "0.875"; // 9:00 PM = 21/24 = 0.875
+const TIME_2_AM: &str = "0.083333333"; // 2:00 AM = 2/24 ≈ 0.083333333
+                                       // Additional helper: 1-second past midnight (00:00:01)
+const TIME_00_00_01: &str = "0.000011574"; // 1 second = 1/86400 ≈ 0.000011574
+
+/// Helper function to set up and evaluate a model with time expressions
+fn test_time_expressions(expressions: &[(&str, &str)]) -> crate::model::Model {
+    let mut model = new_empty_model();
+    for (cell, formula) in expressions {
+        model._set(cell, formula);
+    }
+    model.evaluate();
+    model
+}
+
+/// Helper function to test component extraction for a given time value
+/// Returns (hour, minute, second) as strings
+fn test_component_extraction(time_value: &str) -> (String, String, String) {
+    let model = test_time_expressions(&[
+        ("A1", &format!("=HOUR({time_value})")),
+        ("B1", &format!("=MINUTE({time_value})")),
+        ("C1", &format!("=SECOND({time_value})")),
+    ]);
+    (
+        model._get_text("A1").to_string(),
+        model._get_text("B1").to_string(),
+        model._get_text("C1").to_string(),
+    )
+}
+
+#[test]
+fn test_excel_timevalue_compatibility() {
+    // Test cases based on Excel's official documentation and examples
+    let model = test_time_expressions(&[
+        // Excel documentation examples
+        ("A1", "=TIMEVALUE(\"2:24 AM\")"), // Should be 0.1
+        ("A2", "=TIMEVALUE(\"2 PM\")"),    // Should be 0.583333... (14/24)
+        ("A3", "=TIMEVALUE(\"6:45 PM\")"), // Should be 0.78125 (18.75/24)
+        ("A4", "=TIMEVALUE(\"18:45\")"),   // Same as above, 24-hour format
+        // Date-time format (date should be ignored)
+        ("B1", "=TIMEVALUE(\"22-Aug-2011 6:35 AM\")"), // Should be ~0.2743
+        ("B2", "=TIMEVALUE(\"2023-01-01 14:30:00\")"), // Should be 0.604166667
+        // Edge cases that Excel should support
+        ("C1", "=TIMEVALUE(\"12:00 AM\")"),    // Midnight: 0
+        ("C2", "=TIMEVALUE(\"12:00 PM\")"),    // Noon: 0.5
+        ("C3", "=TIMEVALUE(\"11:59:59 PM\")"), // Almost midnight: 0.999988426
+        // Single digit variations
+        ("D1", "=TIMEVALUE(\"1 AM\")"),  // 1:00 AM
+        ("D2", "=TIMEVALUE(\"9 PM\")"),  // 9:00 PM
+        ("D3", "=TIMEVALUE(\"12 AM\")"), // Midnight
+        ("D4", "=TIMEVALUE(\"12 PM\")"), // Noon
+    ]);
+
+    // Excel documentation examples - verify exact values
+    assert_eq!(model._get_text("A1"), *TIME_2_24_AM); // 2:24 AM
+    assert_eq!(model._get_text("A2"), *TIME_2_PM); // 2 PM = 14:00
+    assert_eq!(model._get_text("A3"), *TIME_6_45_PM); // 6:45 PM = 18:45
+    assert_eq!(model._get_text("A4"), *TIME_6_45_PM); // 18:45 (24-hour)
+
+    // Date-time formats (date ignored, extract time only)
+    assert_eq!(model._get_text("B1"), *TIME_6_35_AM); // 6:35 AM ≈ 0.2743
+    assert_eq!(model._get_text("B2"), *TIME_14_30); // 14:30:00
+
+    // Edge cases
+    assert_eq!(model._get_text("C1"), *MIDNIGHT); // 12:00 AM = 00:00
+    assert_eq!(model._get_text("C2"), *NOON); // 12:00 PM = 12:00
+    assert_eq!(model._get_text("C3"), *TIME_23_59_59); // 11:59:59 PM
+
+    // Single digit hours
+    assert_eq!(model._get_text("D1"), *TIME_1_AM); // 1:00 AM
+    assert_eq!(model._get_text("D2"), *TIME_9_PM); // 9:00 PM = 21:00
+    assert_eq!(model._get_text("D3"), *MIDNIGHT); // 12 AM = 00:00
+    assert_eq!(model._get_text("D4"), *NOON); // 12 PM = 12:00
+}
+
+#[test]
+fn test_time_function_basic_cases() {
+    let model = test_time_expressions(&[
+        ("A1", "=TIME(0,0,0)"),    // Midnight
+        ("A2", "=TIME(12,0,0)"),   // Noon
+        ("A3", "=TIME(14,30,0)"),  // 2:30 PM
+        ("A4", "=TIME(23,59,59)"), // Max time
+    ]);
+
+    assert_eq!(model._get_text("A1"), *MIDNIGHT);
+    assert_eq!(model._get_text("A2"), *NOON);
+    assert_eq!(model._get_text("A3"), *TIME_14_30);
+    assert_eq!(model._get_text("A4"), *TIME_23_59_59);
+}
+
+#[test]
+fn test_time_function_normalization() {
+    let model = test_time_expressions(&[
+        ("A1", "=TIME(25,0,0)"),         // Hours > 24 wrap around
+        ("A2", "=TIME(48,0,0)"),         // 48 hours = 0 (2 full days)
+        ("A3", "=TIME(0,90,0)"),         // 90 minutes = 1.5 hours
+        ("A4", "=TIME(0,0,90)"),         // 90 seconds = 1.5 minutes
+        ("A5", "=TIME(14.9,30.9,59.9)"), // Fractional inputs floored to 14:30:59
+    ]);
+
+    assert_eq!(model._get_text("A1"), *TIME_1_AM); // 1:00:00
+    assert_eq!(model._get_text("A2"), *MIDNIGHT); // 0:00:00
+    assert_eq!(model._get_text("A3"), *"0.0625"); // 1:30:00
+    assert_eq!(model._get_text("A4"), *"0.001041667"); // 0:01:30
+    assert_eq!(model._get_text("A5"), *TIME_14_30_59); // 14:30:59 (floored)
+}
+
+#[test]
+fn test_time_function_precision_edge_cases() {
+    let model = test_time_expressions(&[
+        // High precision fractional seconds
+        ("A1", "=TIME(14,30,45.999)"), // Fractional seconds should be floored
+        ("A2", "=SECOND(TIME(14,30,45.999))"), // Should extract 45, not 46
+        // Very large normalization values
+        ("B1", "=TIME(999,999,999)"), // Extreme normalization test
+        ("B2", "=HOUR(999.5)"),       // Multiple days, extract hour from fractional part
+        ("B3", "=MINUTE(999.75)"),    // Multiple days, extract minute
+        // Boundary conditions at rollover points
+        ("C1", "=TIME(24,60,60)"), // Should normalize to next day (00:01:00)
+        ("C2", "=HOUR(0.999999999)"), // Almost 24 hours should be 23
+        ("C3", "=MINUTE(0.999999999)"), // Almost 24 hours, extract minutes
+        ("C4", "=SECOND(0.999999999)"), // Almost 24 hours, extract seconds
+        // Precision at boundaries
+        ("D1", "=TIME(23,59,59.999)"), // Very close to midnight
+        ("D2", "=TIME(0,0,0.001)"),    // Just after midnight
+    ]);
+
+    // Fractional seconds are floored
+    assert_eq!(model._get_text("A2"), *"45"); // 45.999 floored to 45
+
+    // Multiple days should work with rem_euclid
+    assert_eq!(model._get_text("B2"), *"12"); // 999.5 days, hour = 12 (noon)
+
+    // Boundary normalization
+    assert_eq!(model._get_text("C1"), *"0.042361111"); // 24:60:60 = 01:01:00 (normalized)
+    assert_eq!(model._get_text("C2"), *"23"); // Almost 24 hours = 23:xx:xx
+
+    // High precision should be handled correctly
+    let result_d1 = model._get_text("D1").parse::<f64>().unwrap();
+    assert!(result_d1 < 1.0 && result_d1 > 0.999); // Very close to but less than 1.0
+}
+
+#[test]
+fn test_time_function_errors() {
+    let model = test_time_expressions(&[
+        ("A1", "=TIME()"),          // Wrong arg count
+        ("A2", "=TIME(12)"),        // Wrong arg count
+        ("A3", "=TIME(12,30,0,0)"), // Wrong arg count
+        ("B1", "=TIME(-1,0,0)"),    // Negative hour
+        ("B2", "=TIME(0,-1,0)"),    // Negative minute
+        ("B3", "=TIME(0,0,-1)"),    // Negative second
+    ]);
+
+    // Wrong argument count
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+
+    // Negative values should return #NUM! error
+    assert_eq!(model._get_text("B1"), *"#NUM!");
+    assert_eq!(model._get_text("B2"), *"#NUM!");
+    assert_eq!(model._get_text("B3"), *"#NUM!");
+}
+
+#[test]
+fn test_timevalue_function_formats() {
+    let model = test_time_expressions(&[
+        // Basic formats
+        ("A1", "=TIMEVALUE(\"14:30\")"),
+        ("A2", "=TIMEVALUE(\"14:30:45\")"),
+        ("A3", "=TIMEVALUE(\"00:00:00\")"),
+        // AM/PM formats
+        ("B1", "=TIMEVALUE(\"2:30 PM\")"),
+        ("B2", "=TIMEVALUE(\"2:30 AM\")"),
+        ("B3", "=TIMEVALUE(\"12:00 PM\")"), // Noon
+        ("B4", "=TIMEVALUE(\"12:00 AM\")"), // Midnight
+        // Single hour with AM/PM (now supported!)
+        ("B5", "=TIMEVALUE(\"2 PM\")"),
+        ("B6", "=TIMEVALUE(\"2 AM\")"),
+        // Date-time formats (extract time only)
+        ("C1", "=TIMEVALUE(\"2023-01-01 14:30:00\")"),
+        ("C2", "=TIMEVALUE(\"2023-01-01T14:30:00\")"),
+        // Whitespace handling
+        ("D1", "=TIMEVALUE(\" 14:30 \")"),
+    ]);
+
+    // Basic formats
+    assert_eq!(model._get_text("A1"), *TIME_14_30);
+    assert_eq!(model._get_text("A2"), *TIME_14_30_45);
+    assert_eq!(model._get_text("A3"), *MIDNIGHT);
+
+    // AM/PM formats
+    assert_eq!(model._get_text("B1"), *TIME_14_30); // 2:30 PM = 14:30
+    assert_eq!(model._get_text("B2"), *TIME_2_30_AM); // 2:30 AM
+    assert_eq!(model._get_text("B3"), *NOON); // 12:00 PM = noon
+    assert_eq!(model._get_text("B4"), *MIDNIGHT); // 12:00 AM = midnight
+
+    // Single hour AM/PM formats (now supported!)
+    assert_eq!(model._get_text("B5"), *TIME_2_PM); // 2 PM = 14:00
+    assert_eq!(model._get_text("B6"), *TIME_2_AM); // 2 AM = 02:00
+
+    // Date-time formats
+    assert_eq!(model._get_text("C1"), *TIME_14_30);
+    assert_eq!(model._get_text("C2"), *TIME_14_30);
+
+    // Whitespace
+    assert_eq!(model._get_text("D1"), *TIME_14_30);
+}
+
+#[test]
+fn test_timevalue_function_errors() {
+    let model = test_time_expressions(&[
+        ("A1", "=TIMEVALUE()"),                 // Wrong arg count
+        ("A2", "=TIMEVALUE(\"14:30\", \"x\")"), // Wrong arg count
+        ("B1", "=TIMEVALUE(\"invalid\")"),      // Invalid format
+        ("B2", "=TIMEVALUE(\"25:00\")"),        // Invalid hour
+        ("B3", "=TIMEVALUE(\"14:70\")"),        // Invalid minute
+        ("B4", "=TIMEVALUE(\"\")"),             // Empty string
+        ("B5", "=TIMEVALUE(\"2PM\")"),          // Missing space (still unsupported)
+    ]);
+
+    // Wrong argument count should return #ERROR!
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+
+    // Invalid formats should return #VALUE!
+    assert_eq!(model._get_text("B1"), *"#VALUE!");
+    assert_eq!(model._get_text("B2"), *"#VALUE!");
+    assert_eq!(model._get_text("B3"), *"#VALUE!");
+    assert_eq!(model._get_text("B4"), *"#VALUE!");
+    assert_eq!(model._get_text("B5"), *"#VALUE!"); // "2PM" no space - not supported
+}
+
+#[test]
+fn test_time_component_extraction_comprehensive() {
+    // Test component extraction using helper function for consistency
+
+    // Test basic time values
+    let test_cases = [
+        (MIDNIGHT, ("0", "0", "0")),         // 00:00:00
+        (NOON, ("12", "0", "0")),            // 12:00:00
+        (TIME_14_30, ("14", "30", "0")),     // 14:30:00
+        (TIME_23_59_59, ("23", "59", "59")), // 23:59:59
+    ];
+
+    for (time_value, expected) in test_cases {
+        let (hour, minute, second) = test_component_extraction(time_value);
+        assert_eq!(hour, expected.0, "Hour mismatch for {time_value}");
+        assert_eq!(minute, expected.1, "Minute mismatch for {time_value}");
+        assert_eq!(second, expected.2, "Second mismatch for {time_value}");
+    }
+
+    // Test multiple days (extract from fractional part)
+    let (hour, minute, second) = test_component_extraction("1.5"); // Day 2, 12:00
+    assert_eq!(
+        (hour, minute, second),
+        ("12".to_string(), "0".to_string(), "0".to_string())
+    );
+
+    let (hour, minute, second) = test_component_extraction("100.604166667"); // Day 101, 14:30
+    assert_eq!(
+        (hour, minute, second),
+        ("14".to_string(), "30".to_string(), "0".to_string())
+    );
+
+    // Test precision at boundaries
+    let (hour, _, _) = test_component_extraction("0.041666666"); // Just under 1:00 AM
+    assert_eq!(hour, "0");
+
+    let (hour, _, _) = test_component_extraction("0.041666667"); // Exactly 1:00 AM
+    assert_eq!(hour, "1");
+
+    let (hour, _, _) = test_component_extraction("0.041666668"); // Just over 1:00 AM
+    assert_eq!(hour, "1");
+
+    // Test very large day values
+    let (hour, minute, second) = test_component_extraction("1000000.25"); // Million days + 6 hours
+    assert_eq!(
+        (hour, minute, second),
+        ("6".to_string(), "0".to_string(), "0".to_string())
+    );
+}
+
+#[test]
+fn test_time_component_function_errors() {
+    let model = test_time_expressions(&[
+        // Wrong argument counts
+        ("A1", "=HOUR()"),       // No arguments
+        ("A2", "=MINUTE()"),     // No arguments
+        ("A3", "=SECOND()"),     // No arguments
+        ("A4", "=HOUR(1, 2)"),   // Too many arguments
+        ("A5", "=MINUTE(1, 2)"), // Too many arguments
+        ("A6", "=SECOND(1, 2)"), // Too many arguments
+        // Negative values should return #NUM!
+        ("B1", "=HOUR(-0.5)"),        // Negative value
+        ("B2", "=MINUTE(-1)"),        // Negative value
+        ("B3", "=SECOND(-1)"),        // Negative value
+        ("B4", "=HOUR(-0.000001)"),   // Slightly negative
+        ("B5", "=MINUTE(-0.000001)"), // Slightly negative
+        ("B6", "=SECOND(-0.000001)"), // Slightly negative
+    ]);
+
+    // Wrong argument count should return #ERROR!
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+
+    // Negative values should return #NUM!
+    assert_eq!(model._get_text("B1"), *"#NUM!");
+    assert_eq!(model._get_text("B2"), *"#NUM!");
+    assert_eq!(model._get_text("B3"), *"#NUM!");
+    assert_eq!(model._get_text("B4"), *"#NUM!");
+    assert_eq!(model._get_text("B5"), *"#NUM!");
+    assert_eq!(model._get_text("B6"), *"#NUM!");
+}
+
+#[test]
+fn test_time_functions_integration() {
+    // Test how TIME, TIMEVALUE and component extraction functions work together
+    let model = test_time_expressions(&[
+        // Create times with both functions
+        ("A1", "=TIME(14,30,45)"),
+        ("A2", "=TIMEVALUE(\"14:30:45\")"),
+        // Extract components from TIME function results
+        ("B1", "=HOUR(A1)"),
+        ("B2", "=MINUTE(A1)"),
+        ("B3", "=SECOND(A1)"),
+        // Extract components from TIMEVALUE function results
+        ("C1", "=HOUR(A2)"),
+        ("C2", "=MINUTE(A2)"),
+        ("C3", "=SECOND(A2)"),
+        // Test additional TIME variations
+        ("D1", "=TIME(14,0,0)"), // 14:00:00
+        ("E1", "=HOUR(D1)"),     // Extract hour from 14:00:00
+        ("E2", "=MINUTE(D1)"),   // Extract minute from 14:00:00
+        ("E3", "=SECOND(D1)"),   // Extract second from 14:00:00
+    ]);
+
+    // TIME and TIMEVALUE should produce equivalent results
+    assert_eq!(model._get_text("A1"), model._get_text("A2"));
+
+    // Extracting components should work consistently
+    assert_eq!(model._get_text("B1"), *"14");
+    assert_eq!(model._get_text("B2"), *"30");
+    assert_eq!(model._get_text("B3"), *"45");
+    assert_eq!(model._get_text("C1"), *"14");
+    assert_eq!(model._get_text("C2"), *"30");
+    assert_eq!(model._get_text("C3"), *"45");
+
+    // Components from TIME(14,0,0)
+    assert_eq!(model._get_text("E1"), *"14");
+    assert_eq!(model._get_text("E2"), *"0");
+    assert_eq!(model._get_text("E3"), *"0");
+}
+
+#[test]
+fn test_time_function_extreme_values() {
+    // Test missing edge cases: very large fractional inputs
+    let model = test_time_expressions(&[
+        // Extremely large fractional values to TIME function
+        ("A1", "=TIME(999999.9, 999999.9, 999999.9)"), // Very large fractional inputs
+        ("A2", "=TIME(1e6, 1e6, 1e6)"),                // Scientific notation inputs
+        ("A3", "=TIME(0.000001, 0.000001, 0.000001)"), // Very small fractional inputs
+        // Large day values for component extraction (stress test)
+        ("B1", "=HOUR(999999.999)"), // Almost a million days
+        ("B2", "=MINUTE(999999.999)"),
+        ("B3", "=SECOND(999999.999)"),
+        // Edge case: exactly 1.0 (should be midnight of next day)
+        ("C1", "=HOUR(1.0)"),
+        ("C2", "=MINUTE(1.0)"),
+        ("C3", "=SECOND(1.0)"),
+        // Very high precision values
+        ("D1", "=HOUR(0.999999999999)"), // Almost exactly 24:00:00
+        ("D2", "=MINUTE(0.999999999999)"),
+        ("D3", "=SECOND(0.999999999999)"),
+    ]);
+
+    // Large fractional inputs should be floored and normalized
+    let result_a1 = model._get_text("A1").parse::<f64>().unwrap();
+    assert!(
+        (0.0..1.0).contains(&result_a1),
+        "Result should be valid time fraction"
+    );
+
+    // Component extraction should work with very large values
+    let hour_b1 = model._get_text("B1").parse::<i32>().unwrap();
+    assert!((0..=23).contains(&hour_b1), "Hour should be 0-23");
+
+    // Exactly 1.0 should be midnight (start of next day)
+    assert_eq!(model._get_text("C1"), *"0");
+    assert_eq!(model._get_text("C2"), *"0");
+    assert_eq!(model._get_text("C3"), *"0");
+
+    // Very high precision should still extract valid components
+    let hour_d1 = model._get_text("D1").parse::<i32>().unwrap();
+    assert!((0..=23).contains(&hour_d1), "Hour should be 0-23");
+}
+
+#[test]
+fn test_timevalue_malformed_but_parseable() {
+    // Test missing edge case: malformed but potentially parseable strings
+    let model = test_time_expressions(&[
+        // Test various malformed but potentially parseable time strings
+        ("A1", "=TIMEVALUE(\"14:30:00.123\")"), // Milliseconds (might be truncated)
+        ("A2", "=TIMEVALUE(\"14:30:00.999\")"), // High precision milliseconds
+        ("A3", "=TIMEVALUE(\"02:30:00\")"),     // Leading zero hours
+        ("A4", "=TIMEVALUE(\"2:05:00\")"),      // Single digit hour, zero-padded minute
+        // Boundary cases for AM/PM parsing
+        ("B1", "=TIMEVALUE(\"11:59:59 PM\")"), // Just before midnight
+        ("B2", "=TIMEVALUE(\"12:00:01 AM\")"), // Just after midnight
+        ("B3", "=TIMEVALUE(\"12:00:01 PM\")"), // Just after noon
+        ("B4", "=TIMEVALUE(\"11:59:59 AM\")"), // Just before noon
+        // Test various date-time combinations
+        ("C1", "=TIMEVALUE(\"2023-12-31T23:59:59\")"), // ISO format at year end
+        ("C2", "=TIMEVALUE(\"2023-01-01 00:00:01\")"), // New year, just after midnight
+        // Test potential edge cases that might still be parseable
+        ("D1", "=TIMEVALUE(\"24:00:00\")"), // Should error (invalid hour)
+        ("D2", "=TIMEVALUE(\"23:60:00\")"), // Should error (invalid minute)
+        ("D3", "=TIMEVALUE(\"23:59:60\")"), // Should error (invalid second)
+    ]);
+
+    // Milliseconds are not supported, should return a #VALUE! error like Excel
+    assert_eq!(model._get_text("A1"), *"#VALUE!");
+    assert_eq!(model._get_text("A2"), *"#VALUE!");
+
+    // Leading zeros should work fine
+    assert_eq!(model._get_text("A3"), *TIME_2_30_AM); // 02:30:00 should parse as 2:30:00
+
+    // AM/PM boundary cases should work
+    let result_b1 = model._get_text("B1").parse::<f64>().unwrap();
+    assert!(
+        result_b1 > 0.99 && result_b1 < 1.0,
+        "11:59:59 PM should be very close to 1.0"
+    );
+
+    let result_b2 = model._get_text("B2").parse::<f64>().unwrap();
+    assert!(
+        result_b2 > 0.0 && result_b2 < 0.01,
+        "12:00:01 AM should be very close to 0.0"
+    );
+
+    // ISO 8601 format with "T" separator should be parsed correctly
+    assert_eq!(model._get_text("C1"), *TIME_23_59_59); // 23:59:59 → almost midnight
+    assert_eq!(model._get_text("C2"), *TIME_00_00_01); // 00:00:01 → one second past midnight
+
+    // Time parser normalizes edge cases to midnight (Excel compatibility)
+    assert_eq!(model._get_text("D1"), *"0"); // 24:00:00 = midnight of next day
+    assert_eq!(model._get_text("D2"), *"0"); // 23:60:00 normalizes to 24:00:00 = midnight
+    assert_eq!(model._get_text("D3"), *"0"); // 23:59:60 normalizes to 24:00:00 = midnight
+}
+
+#[test]
+fn test_performance_stress_with_extreme_values() {
+    // Test performance/stress cases with extreme values
+    let model = test_time_expressions(&[
+        // Very large numbers that should still work
+        ("A1", "=TIME(2147483647, 0, 0)"), // Max i32 hours
+        ("A2", "=TIME(0, 2147483647, 0)"), // Max i32 minutes
+        ("A3", "=TIME(0, 0, 2147483647)"), // Max i32 seconds
+        // Component extraction with extreme day values
+        ("B1", "=HOUR(1e15)"), // Very large day number
+        ("B2", "=MINUTE(1e15)"),
+        ("B3", "=SECOND(1e15)"),
+        // Edge of floating point precision
+        ("C1", "=HOUR(1.7976931348623157e+308)"), // Near max f64
+        ("C2", "=HOUR(2.2250738585072014e-308)"), // Near min positive f64
+        // Multiple TIME function calls with large values
+        ("D1", "=TIME(1000000, 1000000, 1000000)"), // Large normalized values
+        ("D2", "=HOUR(D1)"),                        // Extract from large TIME result
+        ("D3", "=MINUTE(D1)"),
+        ("D4", "=SECOND(D1)"),
+    ]);
+
+    // All results should be valid (not errors) even with extreme inputs
+    for cell in ["A1", "A2", "A3", "B1", "B2", "B3", "D1", "D2", "D3", "D4"] {
+        let result = model._get_text(cell);
+        assert!(
+            result != *"#ERROR!" && result != *"#NUM!" && result != *"#VALUE!",
+            "Cell {cell} should not error with extreme values: {result}",
+        );
+    }
+
+    // Results should be mathematically valid
+    let hour_b1 = model._get_text("B1").parse::<i32>().unwrap();
+    let minute_b2 = model._get_text("B2").parse::<i32>().unwrap();
+    let second_b3 = model._get_text("B3").parse::<i32>().unwrap();
+
+    assert!((0..=23).contains(&hour_b1));
+    assert!((0..=59).contains(&minute_b2));
+    assert!((0..=59).contains(&second_b3));
+
+    // TIME function results should be valid time fractions
+    let time_d1 = model._get_text("D1").parse::<f64>().unwrap();
+    assert!(
+        (0.0..1.0).contains(&time_d1),
+        "TIME result should be valid fraction"
+    );
+}

base/src/test/test_issue_483.rs

@@ -0,0 +1,13 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn issue_155() {
+    let mut model = new_empty_model();
+    model._set("A1", "123");
+    model._set("D2", "=-(A1^1.22)");
+    model.evaluate();
+
+    assert_eq!(model._get_formula("D2"), "=-(A1^1.22)".to_string());
+}

base/src/test/test_ln.rs

@@ -0,0 +1,17 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=LN(100)");
+    model._set("A2", "=LN()");
+    model._set("A3", "=LN(100, 10)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"4.605170186");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+}

base/src/test/test_log.rs

@@ -0,0 +1,19 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=LOG(100)");
+    model._set("A2", "=LOG()");
+    model._set("A3", "=LOG(10000, 10)");
+    model._set("A4", "=LOG(100, 10, 1)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"2");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"4");
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+}

base/src/test/test_log10.rs

@@ -0,0 +1,35 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=LOG10(100)");
+    model._set("A2", "=LOG10()");
+    model._set("A3", "=LOG10(100, 10)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"2");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+}
+
+#[test]
+fn cell_and_function() {
+    let mut model = new_empty_model();
+    model._set("A1", "=LOG10");
+
+    model.evaluate();
+
+    // This is the cell LOG10
+    assert_eq!(model._get_text("A1"), *"0");
+
+    model._set("LOG10", "1000");
+    model._set("A2", "=LOG10(LOG10)");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"1000");
+    assert_eq!(model._get_text("A2"), *"3");
+}

base/src/test/test_mod_quotient.rs

@@ -0,0 +1,22 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=MOD(5,2)");
+    model._set("A2", "=MOD()");
+    model._set("A3", "=MOD(5, 2, 1)");
+    model._set("A4", "=QUOTIENT(5, 2)");
+    model._set("A5", "=QUOTIENT()");
+    model._set("A6", "=QUOTIENT(5, 2, 1)");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"1");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+    assert_eq!(model._get_text("A4"), *"2");
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+}

base/src/test/test_mround_trunc_int

@@ -0,0 +1,40 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=MROUND()");
+    model._set("A2", "=MROUND(10)");
+    model._set("A3", "=MROUND(10, 3)");
+    model._set("A4", "=MROUND(10, 3, 1)");
+
+    model._set("A5", "=TRUNC()");
+    model._set("A6", "=TRUNC(10)");
+    model._set("A7", "=TRUNC(10.22, 1)");
+    model._set("A8", "=TRUNC(10, 3, 1)");
+
+    model._set("A9", "=INT()");
+    model._set("A10", "=INT(10.22)");
+    model._set("A11", "=INT(10.22, 1)");
+    model._set("A12", "=INT(10.22, 1, 2)");
+
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"9");
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+    assert_eq!(model._get_text("A7"), *"10.2");
+    assert_eq!(model._get_text("A8"), *"#ERROR!");
+
+    assert_eq!(model._get_text("A9"), *"#ERROR!");
+    assert_eq!(model._get_text("A10"), *"10");
+    assert_eq!(model._get_text("A11"), *"#ERROR!");
+    assert_eq!(model._get_text("A12"), *"#ERROR!");
+}

base/src/test/test_networkdays.rs

@@ -0,0 +1,347 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+// Test data: Jan 1-10, 2023 week
+const JAN_1_2023: i32 = 44927; // Sunday
+const JAN_2_2023: i32 = 44928; // Monday
+const JAN_6_2023: i32 = 44932; // Friday
+const JAN_9_2023: i32 = 44935; // Monday
+const JAN_10_2023: i32 = 44936; // Tuesday
+
+#[test]
+fn networkdays_calculates_weekdays_excluding_weekends() {
+    let mut model = new_empty_model();
+
+    model._set("A1", &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023})"));
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "7",
+        "Should count 7 weekdays in 10-day span"
+    );
+}
+
+#[test]
+fn networkdays_handles_reverse_date_order() {
+    let mut model = new_empty_model();
+
+    model._set("A1", &format!("=NETWORKDAYS({JAN_10_2023},{JAN_1_2023})"));
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "-7",
+        "Reversed dates should return negative count"
+    );
+}
+
+#[test]
+fn networkdays_excludes_holidays_from_weekdays() {
+    let mut model = new_empty_model();
+
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023},{JAN_9_2023})"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "6",
+        "Should exclude Monday holiday from 7 weekdays"
+    );
+}
+
+#[test]
+fn networkdays_handles_same_start_end_date() {
+    let mut model = new_empty_model();
+
+    model._set("A1", &format!("=NETWORKDAYS({JAN_9_2023},{JAN_9_2023})"));
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "1",
+        "Same weekday date should count as 1 workday"
+    );
+}
+
+#[test]
+fn networkdays_accepts_holiday_ranges() {
+    let mut model = new_empty_model();
+
+    model._set("B1", &JAN_2_2023.to_string());
+    model._set("B2", &JAN_6_2023.to_string());
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023},B1:B2)"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "5",
+        "Should exclude 2 holidays from 7 weekdays"
+    );
+}
+
+#[test]
+fn networkdays_intl_uses_standard_weekend_by_default() {
+    let mut model = new_empty_model();
+
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS.INTL({JAN_1_2023},{JAN_10_2023})"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "7",
+        "Default should be Saturday-Sunday weekend"
+    );
+}
+
+#[test]
+fn networkdays_intl_supports_numeric_weekend_patterns() {
+    let mut model = new_empty_model();
+
+    // Pattern 2 = Sunday-Monday weekend
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS.INTL({JAN_1_2023},{JAN_10_2023},2)"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "6",
+        "Sunday-Monday weekend should give 6 workdays"
+    );
+}
+
+#[test]
+fn networkdays_intl_supports_single_day_weekends() {
+    let mut model = new_empty_model();
+
+    // Pattern 11 = Sunday only weekend
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS.INTL({JAN_1_2023},{JAN_10_2023},11)"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "8",
+        "Sunday-only weekend should give 8 workdays"
+    );
+}
+
+#[test]
+fn networkdays_intl_supports_string_weekend_patterns() {
+    let mut model = new_empty_model();
+
+    // "0000110" = Friday-Saturday weekend
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS.INTL({JAN_1_2023},{JAN_10_2023},\"0000110\")"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "8",
+        "Friday-Saturday weekend should give 8 workdays"
+    );
+}
+
+#[test]
+fn networkdays_intl_no_weekends_counts_all_days() {
+    let mut model = new_empty_model();
+
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS.INTL({JAN_1_2023},{JAN_10_2023},\"0000000\")"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "10",
+        "No weekends should count all 10 days"
+    );
+}
+
+#[test]
+fn networkdays_intl_combines_custom_weekends_with_holidays() {
+    let mut model = new_empty_model();
+
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS.INTL({JAN_1_2023},{JAN_10_2023},\"0000110\",{JAN_9_2023})"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "7",
+        "Should exclude both weekend and holiday"
+    );
+}
+
+#[test]
+fn networkdays_validates_argument_count() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=NETWORKDAYS()");
+    model._set("A2", "=NETWORKDAYS(1,2,3,4)");
+    model._set("A3", "=NETWORKDAYS.INTL()");
+    model._set("A4", "=NETWORKDAYS.INTL(1,2,3,4,5)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), "#ERROR!");
+    assert_eq!(model._get_text("A2"), "#ERROR!");
+    assert_eq!(model._get_text("A3"), "#ERROR!");
+    assert_eq!(model._get_text("A4"), "#ERROR!");
+}
+
+#[test]
+fn networkdays_rejects_invalid_dates() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=NETWORKDAYS(-1,100)");
+    model._set("A2", "=NETWORKDAYS(1,3000000)");
+    model._set("A3", "=NETWORKDAYS(\"text\",100)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), "#NUM!");
+    assert_eq!(model._get_text("A2"), "#NUM!");
+    assert_eq!(model._get_text("A3"), "#VALUE!");
+}
+
+#[test]
+fn networkdays_intl_rejects_invalid_weekend_patterns() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=NETWORKDAYS.INTL(1,10,99)");
+    model._set("A2", "=NETWORKDAYS.INTL(1,10,\"111110\")");
+    model._set("A3", "=NETWORKDAYS.INTL(1,10,\"11111000\")");
+    model._set("A4", "=NETWORKDAYS.INTL(1,10,\"1111102\")");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), "#NUM!");
+    assert_eq!(model._get_text("A2"), "#VALUE!");
+    assert_eq!(model._get_text("A3"), "#VALUE!");
+    assert_eq!(model._get_text("A4"), "#VALUE!");
+}
+
+#[test]
+fn networkdays_rejects_invalid_holidays() {
+    let mut model = new_empty_model();
+
+    model._set("B1", "invalid");
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023},B1)"),
+    );
+    model._set(
+        "A2",
+        &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023},-1)"),
+    );
+
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "#VALUE!",
+        "Should reject non-numeric holidays"
+    );
+    assert_eq!(
+        model._get_text("A2"),
+        "#NUM!",
+        "Should reject out-of-range holidays"
+    );
+}
+
+#[test]
+fn networkdays_handles_weekend_only_periods() {
+    let mut model = new_empty_model();
+
+    let saturday = JAN_1_2023 - 1;
+    model._set("A1", &format!("=NETWORKDAYS({saturday},{JAN_1_2023})"));
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "0",
+        "Weekend-only period should count 0 workdays"
+    );
+}
+
+#[test]
+fn networkdays_ignores_holidays_outside_date_range() {
+    let mut model = new_empty_model();
+
+    let future_holiday = JAN_10_2023 + 100;
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023},{future_holiday})"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "7",
+        "Out-of-range holidays should be ignored"
+    );
+}
+
+#[test]
+fn networkdays_handles_empty_holiday_ranges() {
+    let mut model = new_empty_model();
+
+    model._set(
+        "A1",
+        &format!("=NETWORKDAYS({JAN_1_2023},{JAN_10_2023},B1:B3)"),
+    );
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "7",
+        "Empty holiday range should be treated as no holidays"
+    );
+}
+
+#[test]
+fn networkdays_handles_minimum_valid_dates() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=NETWORKDAYS(1,7)");
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "5",
+        "Should handle earliest Excel dates correctly"
+    );
+}
+
+#[test]
+fn networkdays_handles_large_date_ranges_efficiently() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=NETWORKDAYS(1,365)");
+    model.evaluate();
+
+    assert!(
+        !model._get_text("A1").starts_with('#'),
+        "Large ranges should not error"
+    );
+}

base/src/test/test_now.rs

@@ -0,0 +1,30 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::{mock_time, test::util::new_empty_model};
+
+// 14:44 20 Mar 2023 Berlin
+const TIMESTAMP_2023: i64 = 1679319865208;
+
+#[test]
+fn arguments() {
+    let mut model = new_empty_model();
+
+    model._set("A1", "=NOW(1)");
+    model.evaluate();
+
+    assert_eq!(
+        model._get_text("A1"),
+        "#ERROR!",
+        "NOW should not accept arguments"
+    );
+}
+
+#[test]
+fn returns_date_time() {
+    mock_time::set_mock_time(TIMESTAMP_2023);
+    let mut model = new_empty_model();
+    model._set("A1", "=NOW()");
+    model.evaluate();
+    let text = model._get_text("A1");
+    assert_eq!(text, *"20/03/2023 13:44:25");
+}

base/src/test/test_number_format.rs

@@ -8,6 +8,15 @@ fn test_simple_format() {
     assert_eq!(formatted.text, "2.3".to_string());
 }
 
+#[test]
+fn test_maximum_zeros() {
+    let formatted = format_number(1.0 / 3.0, "#,##0.0000000000000000000", "en");
+    assert_eq!(formatted.text, "0.3333333333333330000".to_string());
+
+    let formatted = format_number(1234.0 + 1.0 / 3.0, "#,##0.0000000000000000000", "en");
+    assert_eq!(formatted.text, "1,234.3333333333300000000".to_string());
+}
+
 #[test]
 #[ignore = "not yet implemented"]
 fn test_wrong_locale() {

base/src/test/test_sheet_markup.rs

@@ -21,7 +21,7 @@ fn test_sheet_markup() {
     model.set_cell_style(0, 4, 1, &style).unwrap();
 
     assert_eq!(
-        model.get_sheet_markup(0, 1, 1, 4, 2),
+        model.get_sheet_markup(0),
         Ok("**Item**|**Cost**\nRent|$600\nElectricity|$200\n**Total**|=SUM(B2:B3)".to_string()),
     )
 }

base/src/test/test_sheet_names.rs

@@ -0,0 +1,16 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn sheet_number_name() {
+    let mut model = new_empty_model();
+    model.new_sheet();
+    model._set("A1", "7");
+    model._set("A2", "=Sheet2!C3");
+    model.evaluate();
+    model.rename_sheet("Sheet2", "2024").unwrap();
+    model.evaluate();
+    assert_eq!(model.workbook.get_worksheet_names(), ["Sheet1", "2024"]);
+    assert_eq!(model._get_text("A2"), "0");
+}

base/src/test/test_today.rs

@@ -33,7 +33,8 @@ fn now_basic_utc() {
     model.evaluate();
 
     assert_eq!(model._get_text("A1"), *"20/03/2023");
-    assert_eq!(model._get_text("A2"), *"45005.572511574");
+    // 45005.572511574
+    assert_eq!(model._get_text("A2"), *"20/03/2023 13:44:25");
 }
 
 #[test]
@@ -46,5 +47,5 @@ fn now_basic_europe_berlin() {
 
     assert_eq!(model._get_text("A1"), *"20/03/2023");
     // This is UTC + 1 hour: 45005.572511574 + 1/24
-    assert_eq!(model._get_text("A2"), *"45005.614178241");
+    assert_eq!(model._get_text("A2"), *"20/03/2023 14:44:25");
 }

base/src/test/test_trigonometric.rs

@@ -96,3 +96,14 @@ fn test_fn_tan_pi2() {
     // This is consistent with IEEE 754 but inconsistent with Excel
     assert_eq!(model._get_text("A1"), *"1.63312E+16");
 }
+
+#[test]
+fn test_trigonometric_identity() {
+    let mut model = new_empty_model();
+    model._set("A1", "=COTH(1)*CSCH(1)");
+    model._set("A2", "=COSH(1)/(SINH(1))^2");
+    model._set("A3", "=A1=A2");
+    model.evaluate();
+
+    assert_eq!(model._get_text("A3"), *"TRUE");
+}

base/src/test/test_trigonometric_reciprocals.rs

@@ -0,0 +1,53 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn fn_arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=CSC()");
+    model._set("A2", "=SEC()");
+    model._set("A3", "=COT()");
+
+    model._set("A4", "=CSCH()");
+    model._set("A5", "=SECH()");
+    model._set("A6", "=COTH()");
+
+    model._set("A7", "=ACOT()");
+    model._set("A8", "=ACOTH()");
+
+    model._set("B1", "=CSC(1, 2)");
+    model._set("B2", "=SEC(1, 2)");
+    model._set("B3", "=COT(1, 2)");
+
+    model._set("B4", "=CSCH(1, 2)");
+    model._set("B5", "=SECH(1, 2)");
+    model._set("B6", "=COTH(1, 2)");
+
+    model._set("B7", "=ACOT(1, 2)");
+    model._set("B8", "=ACOTH(1, 2)");
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+    assert_eq!(model._get_text("A2"), *"#ERROR!");
+    assert_eq!(model._get_text("A3"), *"#ERROR!");
+
+    assert_eq!(model._get_text("A4"), *"#ERROR!");
+    assert_eq!(model._get_text("A5"), *"#ERROR!");
+    assert_eq!(model._get_text("A6"), *"#ERROR!");
+
+    assert_eq!(model._get_text("A7"), *"#ERROR!");
+    assert_eq!(model._get_text("A8"), *"#ERROR!");
+
+    assert_eq!(model._get_text("B1"), *"#ERROR!");
+    assert_eq!(model._get_text("B2"), *"#ERROR!");
+    assert_eq!(model._get_text("B3"), *"#ERROR!");
+
+    assert_eq!(model._get_text("B4"), *"#ERROR!");
+    assert_eq!(model._get_text("B5"), *"#ERROR!");
+    assert_eq!(model._get_text("B6"), *"#ERROR!");
+
+    assert_eq!(model._get_text("B7"), *"#ERROR!");
+    assert_eq!(model._get_text("B8"), *"#ERROR!");
+}

base/src/test/test_weekday_return_types.rs

@@ -0,0 +1,26 @@
+use crate::test::util::new_empty_model;
+
+#[test]
+fn test_weekday_return_types_11_to_17() {
+    let mut model = new_empty_model();
+
+    // Test date: 44561 corresponds to a Friday (2021-12-31). We verify the
+    // numeric result for each custom week start defined by return_type 11-17.
+    model._set("A1", "=WEEKDAY(44561,11)"); // Monday start
+    model._set("A2", "=WEEKDAY(44561,12)"); // Tuesday start
+    model._set("A3", "=WEEKDAY(44561,13)"); // Wednesday start
+    model._set("A4", "=WEEKDAY(44561,14)"); // Thursday start
+    model._set("A5", "=WEEKDAY(44561,15)"); // Friday start
+    model._set("A6", "=WEEKDAY(44561,16)"); // Saturday start
+    model._set("A7", "=WEEKDAY(44561,17)"); // Sunday start
+
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"5"); // Mon=1 .. Sun=7 ⇒ Fri=5
+    assert_eq!(model._get_text("A2"), *"4"); // Tue start ⇒ Fri=4
+    assert_eq!(model._get_text("A3"), *"3"); // Wed start ⇒ Fri=3
+    assert_eq!(model._get_text("A4"), *"2"); // Thu start ⇒ Fri=2
+    assert_eq!(model._get_text("A5"), *"1"); // Fri start ⇒ Fri=1
+    assert_eq!(model._get_text("A6"), *"7"); // Sat start ⇒ Fri=7
+    assert_eq!(model._get_text("A7"), *"6"); // Sun start ⇒ Fri=6
+}

base/src/test/test_weeknum_return_types.rs

@@ -0,0 +1,31 @@
+use crate::test::util::new_empty_model;
+
+#[test]
+fn test_weeknum_return_types_11_to_17_and_21() {
+    let mut model = new_empty_model();
+
+    // Date 44561 -> 2021-12-31 (Friday). Previously verified as week 53 (Sunday/Monday start).
+    // We verify that custom week-start codes 11-17 all map to week 53 and ISO variant (21) maps to 52.
+    let formulas = [
+        ("A1", "=WEEKNUM(44561,11)"),
+        ("A2", "=WEEKNUM(44561,12)"),
+        ("A3", "=WEEKNUM(44561,13)"),
+        ("A4", "=WEEKNUM(44561,14)"),
+        ("A5", "=WEEKNUM(44561,15)"),
+        ("A6", "=WEEKNUM(44561,16)"),
+        ("A7", "=WEEKNUM(44561,17)"),
+        ("A8", "=WEEKNUM(44561,21)"), // ISO week numbering
+    ];
+    for (cell, formula) in formulas {
+        model._set(cell, formula);
+    }
+
+    model.evaluate();
+
+    // All 11-17 variations should yield 53
+    for cell in ["A1", "A2", "A3", "A4", "A5", "A6", "A7"] {
+        assert_eq!(model._get_text(cell), *"53", "{cell} should be 53");
+    }
+    // ISO week (return_type 21)
+    assert_eq!(model._get_text("A8"), *"52");
+}

base/src/test/test_yearfrac_basis.rs

@@ -0,0 +1,60 @@
+#![allow(clippy::panic)]
+use crate::{cell::CellValue, test::util::new_empty_model};
+
+#[test]
+fn test_yearfrac_basis_2_actual_360() {
+    let mut model = new_empty_model();
+
+    // Non-leap span of exactly 360 days should result in 1.0
+    model._set("A1", "=YEARFRAC(44561,44921,2)");
+
+    // Leap-year span of 366 days: Jan 1 2020 → Jan 1 2021
+    model._set("A2", "=YEARFRAC(43831,44197,2)");
+
+    // Reverse order should yield negative value
+    model._set("A3", "=YEARFRAC(44921,44561,2)");
+
+    model.evaluate();
+
+    // 360/360
+    assert_eq!(model._get_text("A1"), *"1");
+
+    // 366/360 ≈ 1.0166666667 (tolerance 1e-10)
+    if let Ok(CellValue::Number(v)) = model.get_cell_value_by_ref("Sheet1!A2") {
+        assert!((v - 1.016_666_666_7).abs() < 1e-10);
+    } else {
+        panic!("Expected numeric value in A2");
+    }
+
+    // always positive A1
+    assert_eq!(model._get_text("A3"), *"1");
+}
+
+#[test]
+fn test_yearfrac_basis_3_actual_365() {
+    let mut model = new_empty_model();
+
+    // Non-leap span of exactly 365 days should result in 1.0
+    model._set("B1", "=YEARFRAC(44561,44926,3)");
+
+    // Leap-year span of 366 days
+    model._set("B2", "=YEARFRAC(43831,44197,3)");
+
+    // Same date should be 0
+    model._set("B3", "=YEARFRAC(44561,44561,3)");
+
+    model.evaluate();
+
+    // 365/365
+    assert_eq!(model._get_text("B1"), *"1");
+
+    // 366/365 ≈ 1.002739726 (tolerance 1e-10)
+    if let Ok(CellValue::Number(v)) = model.get_cell_value_by_ref("Sheet1!B2") {
+        assert!((v - 1.002_739_726).abs() < 1e-10);
+    } else {
+        panic!("Expected numeric value in B2");
+    }
+
+    // Same date
+    assert_eq!(model._get_text("B3"), *"0");
+}

base/src/test/user_model/mod.rs

@@ -1,6 +1,7 @@
 mod test_add_delete_sheets;
 mod test_autofill_columns;
 mod test_autofill_rows;
+mod test_batch_row_column_diff;
 mod test_border;
 mod test_clear_cells;
 mod test_column_style;
@@ -11,6 +12,8 @@ mod test_evaluation;
 mod test_general;
 mod test_grid_lines;
 mod test_keyboard_navigation;
+mod test_last_empty_cell;
+mod test_multi_row_column;
 mod test_on_area_selection;
 mod test_on_expand_selected_range;
 mod test_on_paste_styles;

base/src/test/user_model/test_batch_row_column_diff.rs

@@ -0,0 +1,675 @@
+#![allow(clippy::unwrap_used)]
+#![allow(clippy::panic)]
+
+use bitcode::decode;
+
+use crate::{
+    constants::{LAST_COLUMN, LAST_ROW},
+    test::util::new_empty_model,
+    user_model::history::{Diff, QueueDiffs},
+    UserModel,
+};
+
+fn last_diff_list(model: &mut UserModel) -> Vec<Diff> {
+    let bytes = model.flush_send_queue();
+    let queue: Vec<QueueDiffs> = decode(&bytes).unwrap();
+    // Get the last operation's diff list
+    queue.last().unwrap().list.clone()
+}
+
+#[test]
+fn diff_invariant_insert_rows() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    assert!(model.insert_rows(0, 5, 3).is_ok());
+
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    assert!(matches!(
+        &list[0],
+        Diff::InsertRows {
+            sheet: 0,
+            row: 5,
+            count: 3
+        }
+    ));
+}
+
+#[test]
+fn diff_invariant_insert_columns() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    assert!(model.insert_columns(0, 2, 4).is_ok());
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    assert!(matches!(
+        &list[0],
+        Diff::InsertColumns {
+            sheet: 0,
+            column: 2,
+            count: 4
+        }
+    ));
+}
+
+#[test]
+fn undo_redo_after_batch_delete() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Place values that will shift.
+    model.set_user_input(0, 20, 1, "A").unwrap();
+    model.set_user_input(0, 1, 20, "B").unwrap();
+
+    // Fill some of the rows we are about to delete for testing
+    for r in 10..15 {
+        model.set_user_input(0, r, 1, "tmp").unwrap();
+    }
+
+    // Delete rows 10..14 and columns 5..8
+    assert!(model.delete_rows(0, 10, 5).is_ok());
+    assert!(model.delete_columns(0, 5, 4).is_ok());
+
+    // Verify shift
+    assert_eq!(model.get_formatted_cell_value(0, 15, 1).unwrap(), "A");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 16).unwrap(), "B");
+
+    // Undo
+    model.undo().unwrap(); // columns
+    model.undo().unwrap(); // rows
+    assert_eq!(model.get_formatted_cell_value(0, 20, 1).unwrap(), "A");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 20).unwrap(), "B");
+
+    // Redo
+    model.redo().unwrap(); // rows
+    model.redo().unwrap(); // columns
+    assert_eq!(model.get_formatted_cell_value(0, 15, 1).unwrap(), "A");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 16).unwrap(), "B");
+}
+
+#[test]
+fn diff_order_delete_rows() {
+    // Verifies that delete diffs are generated with all data preserved
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Populate rows to delete
+    for r in 5..10 {
+        model.set_user_input(0, r, 1, &r.to_string()).unwrap();
+    }
+
+    assert!(model.delete_rows(0, 5, 5).is_ok());
+
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+
+    // Should have one bulk diff with all the row data
+    match &list[0] {
+        Diff::DeleteRows {
+            sheet,
+            row,
+            count,
+            old_data,
+        } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*row, 5);
+            assert_eq!(*count, 5);
+            assert_eq!(old_data.len(), 5);
+            // Verify the data was collected for each row
+            for (i, row_data) in old_data.iter().enumerate() {
+                let _expected_value = (5 + i).to_string();
+                assert!(row_data.data.contains_key(&1));
+            }
+        }
+        _ => panic!("Unexpected diff variant"),
+    }
+}
+
+#[test]
+fn batch_operations_with_formulas() {
+    // Verifies formulas update correctly after batch ops
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    model.set_user_input(0, 1, 1, "10").unwrap();
+    model.set_user_input(0, 5, 1, "=A1*2").unwrap(); // Will become A3 after insert
+
+    assert!(model.insert_rows(0, 2, 2).is_ok());
+
+    // Formula should now reference A1 (unchanged) but be in row 7
+    assert_eq!(model.get_formatted_cell_value(0, 7, 1).unwrap(), "20");
+    assert_eq!(model.get_cell_content(0, 7, 1).unwrap(), "=A1*2");
+
+    // Undo and verify formula is back at original position
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 5, 1).unwrap(), "20");
+}
+
+#[test]
+fn edge_case_single_operation() {
+    // Single row/column operations should still work correctly
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    assert!(model.insert_rows(0, 1, 1).is_ok());
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+
+    assert!(model.insert_columns(0, 1, 1).is_ok());
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+}
+
+#[test]
+fn delete_empty_rows() {
+    // Delete multiple empty rows and verify behavior
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set data in rows 1 and 10, leaving rows 5-8 empty
+    model.set_user_input(0, 1, 1, "Before").unwrap();
+    model.set_user_input(0, 10, 1, "After").unwrap();
+
+    // Delete empty rows 5-8
+    assert!(model.delete_rows(0, 5, 4).is_ok());
+
+    // Verify shift
+    assert_eq!(model.get_formatted_cell_value(0, 1, 1).unwrap(), "Before");
+    assert_eq!(model.get_formatted_cell_value(0, 6, 1).unwrap(), "After");
+
+    // Verify diffs now use bulk operation
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::DeleteRows {
+            sheet,
+            row,
+            count,
+            old_data,
+        } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*row, 5);
+            assert_eq!(*count, 4);
+            assert_eq!(old_data.len(), 4);
+            // All rows should be empty
+            for row_data in old_data {
+                assert!(row_data.data.is_empty());
+            }
+        }
+        _ => panic!("Unexpected diff variant"),
+    }
+
+    // Undo/redo
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 10, 1).unwrap(), "After");
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 6, 1).unwrap(), "After");
+}
+
+#[test]
+fn delete_mixed_empty_and_filled_rows() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Alternating filled and empty rows
+    model.set_user_input(0, 5, 1, "Row5").unwrap();
+    model.set_user_input(0, 7, 1, "Row7").unwrap();
+    model.set_user_input(0, 9, 1, "Row9").unwrap();
+    model.set_user_input(0, 10, 1, "After").unwrap();
+
+    assert!(model.delete_rows(0, 5, 5).is_ok());
+    assert_eq!(model.get_formatted_cell_value(0, 5, 1).unwrap(), "After");
+
+    // Verify mix of empty and filled row diffs
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::DeleteRows {
+            sheet,
+            row,
+            count,
+            old_data,
+        } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*row, 5);
+            assert_eq!(*count, 5);
+            assert_eq!(old_data.len(), 5);
+
+            // Count filled rows (should be 3: rows 5, 7, 9)
+            let filled_count = old_data
+                .iter()
+                .filter(|row_data| !row_data.data.is_empty())
+                .count();
+            assert_eq!(filled_count, 3);
+        }
+        _ => panic!("Unexpected diff variant"),
+    }
+
+    // Undo
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 5, 1).unwrap(), "Row5");
+    assert_eq!(model.get_formatted_cell_value(0, 7, 1).unwrap(), "Row7");
+    assert_eq!(model.get_formatted_cell_value(0, 9, 1).unwrap(), "Row9");
+    assert_eq!(model.get_formatted_cell_value(0, 10, 1).unwrap(), "After");
+}
+
+#[test]
+fn bulk_insert_rows_undo_redo() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set up initial data
+    model.set_user_input(0, 1, 1, "A1").unwrap();
+    model.set_user_input(0, 2, 1, "A2").unwrap();
+    model.set_user_input(0, 5, 1, "A5").unwrap();
+
+    // Insert 3 rows at position 3
+    assert!(model.insert_rows(0, 3, 3).is_ok());
+
+    // Verify data has shifted
+    assert_eq!(model.get_formatted_cell_value(0, 1, 1).unwrap(), "A1");
+    assert_eq!(model.get_formatted_cell_value(0, 2, 1).unwrap(), "A2");
+    assert_eq!(model.get_formatted_cell_value(0, 8, 1).unwrap(), "A5"); // A5 moved to A8
+
+    // Check diff structure
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    assert!(matches!(
+        &list[0],
+        Diff::InsertRows {
+            sheet: 0,
+            row: 3,
+            count: 3
+        }
+    ));
+
+    // Undo
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 5, 1).unwrap(), "A5"); // Back to original position
+
+    // Redo
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 8, 1).unwrap(), "A5"); // Shifted again
+}
+
+#[test]
+fn bulk_insert_columns_undo_redo() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set up initial data
+    model.set_user_input(0, 1, 1, "A1").unwrap();
+    model.set_user_input(0, 1, 2, "B1").unwrap();
+    model.set_user_input(0, 1, 5, "E1").unwrap();
+
+    // Insert 3 columns at position 3
+    assert!(model.insert_columns(0, 3, 3).is_ok());
+
+    // Verify data has shifted
+    assert_eq!(model.get_formatted_cell_value(0, 1, 1).unwrap(), "A1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 2).unwrap(), "B1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 8).unwrap(), "E1"); // E1 moved to H1
+
+    // Check diff structure
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    assert!(matches!(
+        &list[0],
+        Diff::InsertColumns {
+            sheet: 0,
+            column: 3,
+            count: 3
+        }
+    ));
+
+    // Undo
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 5).unwrap(), "E1"); // Back to original position
+
+    // Redo
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 8).unwrap(), "E1"); // Shifted again
+}
+
+#[test]
+fn bulk_delete_rows_round_trip() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set up data with styles
+    model.set_user_input(0, 3, 1, "Row3").unwrap();
+    model.set_user_input(0, 4, 1, "Row4").unwrap();
+    model.set_user_input(0, 5, 1, "Row5").unwrap();
+    model.set_user_input(0, 6, 1, "Row6").unwrap();
+    model.set_user_input(0, 7, 1, "After").unwrap();
+
+    // Set some row heights to verify they're preserved
+    model.set_rows_height(0, 4, 4, 30.0).unwrap();
+    model.set_rows_height(0, 5, 5, 40.0).unwrap();
+
+    // Delete rows 3-6
+    assert!(model.delete_rows(0, 3, 4).is_ok());
+
+    // Verify deletion
+    assert_eq!(model.get_formatted_cell_value(0, 3, 1).unwrap(), "After");
+
+    // Check diff structure
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::DeleteRows {
+            sheet,
+            row,
+            count,
+            old_data,
+        } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*row, 3);
+            assert_eq!(*count, 4);
+            assert_eq!(old_data.len(), 4);
+            // Verify data was preserved
+            assert!(old_data[0].data.contains_key(&1)); // Row3
+            assert!(old_data[1].data.contains_key(&1)); // Row4
+            assert!(old_data[2].data.contains_key(&1)); // Row5
+            assert!(old_data[3].data.contains_key(&1)); // Row6
+        }
+        _ => panic!("Expected DeleteRows diff"),
+    }
+
+    // Undo - should restore all data and row heights
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 3, 1).unwrap(), "Row3");
+    assert_eq!(model.get_formatted_cell_value(0, 4, 1).unwrap(), "Row4");
+    assert_eq!(model.get_formatted_cell_value(0, 5, 1).unwrap(), "Row5");
+    assert_eq!(model.get_formatted_cell_value(0, 6, 1).unwrap(), "Row6");
+    assert_eq!(model.get_formatted_cell_value(0, 7, 1).unwrap(), "After");
+    assert_eq!(model.get_row_height(0, 4).unwrap(), 30.0);
+    assert_eq!(model.get_row_height(0, 5).unwrap(), 40.0);
+
+    // Redo - should delete again
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 3, 1).unwrap(), "After");
+
+    // Final undo to verify round-trip
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 3, 1).unwrap(), "Row3");
+    assert_eq!(model.get_formatted_cell_value(0, 4, 1).unwrap(), "Row4");
+    assert_eq!(model.get_formatted_cell_value(0, 5, 1).unwrap(), "Row5");
+    assert_eq!(model.get_formatted_cell_value(0, 6, 1).unwrap(), "Row6");
+}
+
+#[test]
+fn bulk_delete_columns_round_trip() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set up data with styles
+    model.set_user_input(0, 1, 3, "C1").unwrap();
+    model.set_user_input(0, 1, 4, "D1").unwrap();
+    model.set_user_input(0, 1, 5, "E1").unwrap();
+    model.set_user_input(0, 1, 6, "F1").unwrap();
+    model.set_user_input(0, 1, 7, "After").unwrap();
+
+    // Set some column widths to verify they're preserved
+    model.set_columns_width(0, 4, 4, 100.0).unwrap();
+    model.set_columns_width(0, 5, 5, 120.0).unwrap();
+
+    // Delete columns 3-6
+    assert!(model.delete_columns(0, 3, 4).is_ok());
+
+    // Verify deletion
+    assert_eq!(model.get_formatted_cell_value(0, 1, 3).unwrap(), "After");
+
+    // Check diff structure
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::DeleteColumns {
+            sheet,
+            column,
+            count,
+            old_data,
+        } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*column, 3);
+            assert_eq!(*count, 4);
+            assert_eq!(old_data.len(), 4);
+            // Verify data was preserved
+            assert!(old_data[0].data.contains_key(&1)); // C1
+            assert!(old_data[1].data.contains_key(&1)); // D1
+            assert!(old_data[2].data.contains_key(&1)); // E1
+            assert!(old_data[3].data.contains_key(&1)); // F1
+        }
+        _ => panic!("Expected DeleteColumns diff"),
+    }
+
+    // Undo - should restore all data and column widths
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 3).unwrap(), "C1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 4).unwrap(), "D1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 5).unwrap(), "E1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 6).unwrap(), "F1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 7).unwrap(), "After");
+    assert_eq!(model.get_column_width(0, 4).unwrap(), 100.0);
+    assert_eq!(model.get_column_width(0, 5).unwrap(), 120.0);
+
+    // Redo - should delete again
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 3).unwrap(), "After");
+
+    // Final undo to verify round-trip
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 3).unwrap(), "C1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 4).unwrap(), "D1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 5).unwrap(), "E1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 6).unwrap(), "F1");
+}
+
+#[test]
+fn complex_bulk_operations_sequence() {
+    // Test a complex sequence of bulk operations
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Initial setup
+    model.set_user_input(0, 1, 1, "A1").unwrap();
+    model.set_user_input(0, 2, 2, "B2").unwrap();
+    model.set_user_input(0, 3, 3, "C3").unwrap();
+
+    // Operation 1: Insert 2 rows at position 2
+    model.insert_rows(0, 2, 2).unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 1).unwrap(), "A1");
+    assert_eq!(model.get_formatted_cell_value(0, 4, 2).unwrap(), "B2"); // B2 moved down
+    assert_eq!(model.get_formatted_cell_value(0, 5, 3).unwrap(), "C3"); // C3 moved down
+
+    // Operation 2: Insert 2 columns at position 2
+    model.insert_columns(0, 2, 2).unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 1).unwrap(), "A1");
+    assert_eq!(model.get_formatted_cell_value(0, 4, 4).unwrap(), "B2"); // B2 moved right
+    assert_eq!(model.get_formatted_cell_value(0, 5, 5).unwrap(), "C3"); // C3 moved right
+
+    // Operation 3: Delete the inserted rows
+    model.delete_rows(0, 2, 2).unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 2, 4).unwrap(), "B2");
+    assert_eq!(model.get_formatted_cell_value(0, 3, 5).unwrap(), "C3");
+
+    // Undo all operations
+    model.undo().unwrap(); // Undo delete rows
+    assert_eq!(model.get_formatted_cell_value(0, 4, 4).unwrap(), "B2");
+    assert_eq!(model.get_formatted_cell_value(0, 5, 5).unwrap(), "C3");
+
+    model.undo().unwrap(); // Undo insert columns
+    assert_eq!(model.get_formatted_cell_value(0, 4, 2).unwrap(), "B2");
+    assert_eq!(model.get_formatted_cell_value(0, 5, 3).unwrap(), "C3");
+
+    model.undo().unwrap(); // Undo insert rows
+    assert_eq!(model.get_formatted_cell_value(0, 2, 2).unwrap(), "B2");
+    assert_eq!(model.get_formatted_cell_value(0, 3, 3).unwrap(), "C3");
+
+    // Redo all operations
+    model.redo().unwrap(); // Redo insert rows
+    model.redo().unwrap(); // Redo insert columns
+    model.redo().unwrap(); // Redo delete rows
+    assert_eq!(model.get_formatted_cell_value(0, 2, 4).unwrap(), "B2");
+    assert_eq!(model.get_formatted_cell_value(0, 3, 5).unwrap(), "C3");
+}
+
+#[test]
+fn bulk_operations_with_formulas_update() {
+    // Test that formulas update correctly with bulk operations
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set up data and formulas
+    model.set_user_input(0, 1, 1, "10").unwrap();
+    model.set_user_input(0, 5, 1, "20").unwrap();
+    model.set_user_input(0, 10, 1, "=A1+A5").unwrap(); // Formula referencing A1 and A5
+
+    // Insert 3 rows at position 3
+    model.insert_rows(0, 3, 3).unwrap();
+
+    // Formula should update to reference the shifted cells
+    assert_eq!(model.get_formatted_cell_value(0, 13, 1).unwrap(), "30"); // Formula moved down
+    assert_eq!(model.get_cell_content(0, 13, 1).unwrap(), "=A1+A8"); // A5 became A8
+
+    // Undo
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 10, 1).unwrap(), "30");
+    assert_eq!(model.get_cell_content(0, 10, 1).unwrap(), "=A1+A5");
+
+    // Now test column insertion
+    model.set_user_input(0, 1, 5, "20").unwrap(); // Add value in E1
+    model.set_user_input(0, 1, 10, "=A1+E1").unwrap();
+    model.insert_columns(0, 3, 2).unwrap();
+
+    assert_eq!(model.get_formatted_cell_value(0, 1, 12).unwrap(), "30"); // Formula moved right
+    assert_eq!(model.get_cell_content(0, 1, 12).unwrap(), "=A1+G1"); // E1 became G1
+}
+
+#[test]
+fn bulk_delete_with_styles() {
+    // Test that cell and row/column styles are preserved
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set up data with various styles
+    for r in 5..10 {
+        model.set_user_input(0, r, 1, &format!("Row{r}")).unwrap();
+        model.set_rows_height(0, r, r, (r * 10) as f64).unwrap();
+    }
+
+    // Delete and verify style preservation
+    model.delete_rows(0, 5, 5).unwrap();
+
+    // Undo should restore all styles
+    model.undo().unwrap();
+    for r in 5..10 {
+        assert_eq!(
+            model.get_formatted_cell_value(0, r, 1).unwrap(),
+            format!("Row{r}")
+        );
+        assert_eq!(model.get_row_height(0, r).unwrap(), (r * 10) as f64);
+    }
+}
+
+#[test]
+fn bulk_operations_large_count() {
+    // Test operations with large counts
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Insert a large number of rows
+    model.set_user_input(0, 1, 1, "Before").unwrap();
+    model.set_user_input(0, 100, 1, "After").unwrap();
+
+    assert!(model.insert_rows(0, 50, 100).is_ok());
+
+    // Verify shift
+    assert_eq!(model.get_formatted_cell_value(0, 1, 1).unwrap(), "Before");
+    assert_eq!(model.get_formatted_cell_value(0, 200, 1).unwrap(), "After"); // Moved by 100
+
+    // Check diff
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    assert!(matches!(
+        &list[0],
+        Diff::InsertRows {
+            sheet: 0,
+            row: 50,
+            count: 100
+        }
+    ));
+
+    // Undo and redo
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 100, 1).unwrap(), "After");
+
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 200, 1).unwrap(), "After");
+}
+
+#[test]
+fn bulk_operations_error_cases() {
+    // Test error conditions
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Negative count should fail
+    assert!(model.insert_rows(0, 1, -5).is_err());
+    assert!(model.insert_columns(0, 1, -5).is_err());
+    assert!(model.delete_rows(0, 1, -5).is_err());
+    assert!(model.delete_columns(0, 1, -5).is_err());
+
+    // Zero count should fail
+    assert!(model.insert_rows(0, 1, 0).is_err());
+    assert!(model.insert_columns(0, 1, 0).is_err());
+    assert!(model.delete_rows(0, 1, 0).is_err());
+    assert!(model.delete_columns(0, 1, 0).is_err());
+
+    // Out of bounds operations should fail
+    assert!(model.delete_rows(0, LAST_ROW - 5, 10).is_err());
+    assert!(model.delete_columns(0, LAST_COLUMN - 5, 10).is_err());
+}
+
+#[test]
+fn bulk_diff_serialization() {
+    // Test that bulk diffs can be serialized/deserialized correctly
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Create some data
+    model.set_user_input(0, 1, 1, "Test").unwrap();
+    model.insert_rows(0, 2, 3).unwrap();
+
+    // Flush and get the serialized diffs
+    let bytes = model.flush_send_queue();
+
+    // Create a new model and apply the diffs
+    let base2 = new_empty_model();
+    let mut model2 = UserModel::from_model(base2);
+
+    assert!(model2.apply_external_diffs(&bytes).is_ok());
+
+    // Verify the state matches
+    assert_eq!(model2.get_formatted_cell_value(0, 1, 1).unwrap(), "Test");
+}
+
+#[test]
+fn boundary_validation() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Test deleting rows beyond valid range
+    assert!(model.delete_rows(0, LAST_ROW, 2).is_err());
+    assert!(model.delete_rows(0, LAST_ROW + 1, 1).is_err());
+
+    // Test deleting columns beyond valid range
+    assert!(model.delete_columns(0, LAST_COLUMN, 2).is_err());
+    assert!(model.delete_columns(0, LAST_COLUMN + 1, 1).is_err());
+
+    // Test valid boundary deletions (should work with our empty row fix)
+    assert!(model.delete_rows(0, LAST_ROW, 1).is_ok());
+    assert!(model.delete_columns(0, LAST_COLUMN, 1).is_ok());
+}

base/src/test/user_model/test_border.rs

@@ -50,10 +50,7 @@ fn check_borders(model: &UserModel) {
                         assert_eq!(
                             Some(top_border),
                             top_cell_style.border.bottom,
-                            "(Top). Sheet: {}, row: {}, column: {}",
+                            "(Top). Sheet: {sheet}, row: {row}, column: {column}"
-                            sheet,
-                            row,
-                            column
                         );
                     }
                 }
@@ -65,10 +62,7 @@ fn check_borders(model: &UserModel) {
                         assert_eq!(
                             Some(right_border),
                             right_cell_style.border.left,
-                            "(Right). Sheet: {}, row: {}, column: {}",
+                            "(Right). Sheet: {sheet}, row: {row}, column: {column}"
-                            sheet,
-                            row,
-                            column
                         );
                     }
                 }
@@ -80,10 +74,7 @@ fn check_borders(model: &UserModel) {
                         assert_eq!(
                             Some(bottom_border),
                             bottom_cell_style.border.top,
-                            "(Bottom). Sheet: {}, row: {}, column: {}",
+                            "(Bottom). Sheet: {sheet}, row: {row}, column: {column}"
-                            sheet,
-                            row,
-                            column
                         );
                     }
                 }
@@ -94,10 +85,7 @@ fn check_borders(model: &UserModel) {
                         assert_eq!(
                             Some(left_border),
                             left_cell_style.border.right,
-                            "(Left). Sheet: {}, row: {}, column: {}",
+                            "(Left). Sheet: {sheet}, row: {row}, column: {column}"
-                            sheet,
-                            row,
-                            column
                         );
                     }
                 }

base/src/test/user_model/test_clear_cells.rs

@@ -89,3 +89,67 @@ fn clear_all_empty_cell() {
     model.undo().unwrap();
     assert_eq!(model.get_formatted_cell_value(0, 1, 1), Ok("".to_string()));
 }
+
+#[test]
+fn issue_454() {
+    let mut model = UserModel::new_empty("model", "en", "UTC").unwrap();
+    model
+        .set_user_input(
+            0,
+            1,
+            1,
+            "Le presbytère n'a rien perdu de son charme, ni le jardin de son éclat.",
+        )
+        .unwrap();
+    model.set_user_input(0, 1, 2, "=ISTEXT(A1)").unwrap();
+    assert_eq!(
+        model.get_formatted_cell_value(0, 1, 2),
+        Ok("TRUE".to_string())
+    );
+    model
+        .range_clear_contents(&Area {
+            sheet: 0,
+            row: 1,
+            column: 1,
+            width: 1,
+            height: 1,
+        })
+        .unwrap();
+    assert_eq!(
+        model.get_formatted_cell_value(0, 1, 2),
+        Ok("FALSE".to_string())
+    );
+    model.undo().unwrap();
+}
+
+#[test]
+fn issue_454b() {
+    let mut model = UserModel::new_empty("model", "en", "UTC").unwrap();
+    model
+        .set_user_input(
+            0,
+            1,
+            1,
+            "Le presbytère n'a rien perdu de son charme, ni le jardin de son éclat.",
+        )
+        .unwrap();
+    model.set_user_input(0, 1, 2, "=ISTEXT(A1)").unwrap();
+    assert_eq!(
+        model.get_formatted_cell_value(0, 1, 2),
+        Ok("TRUE".to_string())
+    );
+    model
+        .range_clear_all(&Area {
+            sheet: 0,
+            row: 1,
+            column: 1,
+            width: 1,
+            height: 1,
+        })
+        .unwrap();
+    assert_eq!(
+        model.get_formatted_cell_value(0, 1, 2),
+        Ok("FALSE".to_string())
+    );
+    model.undo().unwrap();
+}

base/src/test/user_model/test_defined_names.rs

@@ -254,19 +254,19 @@ fn invalid_names() {
     // spaces
     assert_eq!(
         model.new_defined_name("A real", None, "Sheet1!$A$1"),
-        Err("Invalid defined name".to_string())
+        Err("Name: Invalid defined name".to_string())
     );
 
     // Starts with number
     assert_eq!(
         model.new_defined_name("2real", None, "Sheet1!$A$1"),
-        Err("Invalid defined name".to_string())
+        Err("Name: Invalid defined name".to_string())
     );
 
     // Updating also fails
     assert_eq!(
         model.update_defined_name("MyName", None, "My Name", None, "Sheet1!$A$1"),
-        Err("Invalid defined name".to_string())
+        Err("Name: Invalid defined name".to_string())
     );
 }
 
@@ -284,13 +284,13 @@ fn already_existing() {
     // Can't create a new name with the same name
     assert_eq!(
         model.new_defined_name("MyName", None, "Sheet1!$A$2"),
-        Err("Defined name already exists".to_string())
+        Err("Name: Defined name already exists".to_string())
     );
 
     // Can't update one into an existing
     assert_eq!(
         model.update_defined_name("Another", None, "MyName", None, "Sheet1!$A$1"),
-        Err("Defined name already exists".to_string())
+        Err("Name: Defined name already exists".to_string())
     );
 }
 
@@ -304,17 +304,17 @@ fn invalid_sheet() {
 
     assert_eq!(
         model.new_defined_name("Mything", Some(2), "Sheet1!$A$1"),
-        Err("Invalid sheet index".to_string())
+        Err("Scope: Invalid sheet index".to_string())
     );
 
     assert_eq!(
         model.update_defined_name("MyName", None, "MyName", Some(2), "Sheet1!$A$1"),
-        Err("Invalid sheet index".to_string())
+        Err("Scope: Invalid sheet index".to_string())
     );
 
     assert_eq!(
         model.update_defined_name("MyName", Some(9), "YourName", None, "Sheet1!$A$1"),
-        Err("Invalid sheet index".to_string())
+        Err("General: Failed to get old name".to_string())
     );
 }
 
@@ -322,7 +322,7 @@ fn invalid_sheet() {
 fn invalid_formula() {
     let mut model = UserModel::new_empty("model", "en", "UTC").unwrap();
     model.set_user_input(0, 1, 1, "Hello").unwrap();
-    model.new_defined_name("MyName", None, "A1").unwrap();
+    assert!(model.new_defined_name("MyName", None, "A1").is_err());
 
     model.set_user_input(0, 1, 2, "=MyName").unwrap();
 

base/src/test/user_model/test_diff_queue.rs

@@ -65,8 +65,8 @@ fn queue_undo_redo_multiple() {
         model1.set_user_input(0, row, 17, "=ROW()").unwrap();
     }
 
-    model1.insert_row(0, 3).unwrap();
+    model1.insert_rows(0, 3, 1).unwrap();
-    model1.insert_row(0, 3).unwrap();
+    model1.insert_rows(0, 3, 1).unwrap();
 
     // undo al of them
     while model1.can_undo() {

base/src/test/user_model/test_general.rs

@@ -26,7 +26,7 @@ fn set_user_input_errors() {
 #[test]
 fn user_model_debug_message() {
     let model = UserModel::new_empty("model", "en", "UTC").unwrap();
-    let s = &format!("{:?}", model);
+    let s = &format!("{model:?}");
     assert_eq!(s, "UserModel");
 }
 
@@ -62,7 +62,7 @@ fn insert_remove_rows() {
     assert!(model.set_rows_height(0, 5, 5, 3.0 * height).is_ok());
 
     // remove the row
-    assert!(model.delete_row(0, 5).is_ok());
+    assert!(model.delete_rows(0, 5, 1).is_ok());
     // Row 5 has now the normal height
     assert_eq!(model.get_row_height(0, 5), Ok(height));
     // There is no value in A5
@@ -99,7 +99,7 @@ fn insert_remove_columns() {
     assert_eq!(model.get_column_width(0, 5).unwrap(), 3.0 * column_width);
 
     // remove the column
-    assert!(model.delete_column(0, 5).is_ok());
+    assert!(model.delete_columns(0, 5, 1).is_ok());
     // Column 5 has now the normal width
     assert_eq!(model.get_column_width(0, 5), Ok(column_width));
     // There is no value in E5

base/src/test/user_model/test_last_empty_cell.rs

@@ -0,0 +1,55 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::constants::LAST_ROW;
+use crate::expressions::types::Area;
+use crate::test::util::new_empty_model;
+use crate::UserModel;
+
+#[test]
+fn basic_tests() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+    // This is the first row, column 5
+    model.set_user_input(0, 3, 5, "todo").unwrap();
+
+    // Row 3 before column 5 should be empty
+    assert_eq!(
+        model
+            .get_last_non_empty_in_row_before_column(0, 3, 4)
+            .unwrap(),
+        None
+    );
+    // Row 3 before column 5 should be 5
+    assert_eq!(
+        model
+            .get_last_non_empty_in_row_before_column(0, 3, 7)
+            .unwrap(),
+        Some(5)
+    );
+}
+
+#[test]
+fn test_last_empty_cell() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+
+    let column_g_range = Area {
+        sheet: 0,
+        row: 1,
+        column: 7,
+        width: 1,
+        height: LAST_ROW,
+    };
+
+    model
+        .update_range_style(&column_g_range, "fill.bg_color", "#333444")
+        .unwrap();
+
+    // Column 7 has a style but it is empty
+    assert_eq!(
+        model
+            .get_last_non_empty_in_row_before_column(0, 3, 14)
+            .unwrap(),
+        None
+    );
+}

base/src/test/user_model/test_multi_row_column.rs

@@ -0,0 +1,173 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::{
+    constants::{LAST_COLUMN, LAST_ROW},
+    test::util::new_empty_model,
+    UserModel,
+};
+
+#[test]
+fn insert_multiple_rows_shifts_cells() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+    // Place a value below the insertion point.
+    model.set_user_input(0, 10, 1, "42").unwrap();
+
+    // Insert 3 rows starting at row 5.
+    assert!(model.insert_rows(0, 5, 3).is_ok());
+
+    // The original value should have moved down by 3 rows.
+    assert_eq!(model.get_formatted_cell_value(0, 13, 1).unwrap(), "42");
+
+    // Undo / redo cycle should restore the same behaviour.
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 10, 1).unwrap(), "42");
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 13, 1).unwrap(), "42");
+}
+
+#[test]
+fn insert_rows_errors() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+
+    // Negative or zero counts are rejected.
+    assert_eq!(
+        model.insert_rows(0, 1, -2),
+        Err("Cannot add a negative number of cells :)".to_string())
+    );
+    assert_eq!(
+        model.insert_rows(0, 1, 0),
+        Err("Cannot add a negative number of cells :)".to_string())
+    );
+
+    // Inserting too many rows so that the sheet would overflow.
+    let too_many = LAST_ROW; // This guarantees max_row + too_many > LAST_ROW.
+    assert_eq!(
+        model.insert_rows(0, 1, too_many),
+        Err(
+            "Cannot shift cells because that would delete cells at the end of a column".to_string()
+        )
+    );
+}
+
+#[test]
+fn insert_multiple_columns_shifts_cells() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+    // Place a value to the right of the insertion point.
+    model.set_user_input(0, 1, 10, "99").unwrap();
+
+    // Insert 3 columns starting at column 5.
+    assert!(model.insert_columns(0, 5, 3).is_ok());
+
+    // The original value should have moved right by 3 columns.
+    assert_eq!(model.get_formatted_cell_value(0, 1, 13).unwrap(), "99");
+
+    // Undo / redo cycle.
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 10).unwrap(), "99");
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 13).unwrap(), "99");
+}
+
+#[test]
+fn insert_columns_errors() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+
+    // Negative or zero counts are rejected.
+    assert_eq!(
+        model.insert_columns(0, 1, -2),
+        Err("Cannot add a negative number of cells :)".to_string())
+    );
+    assert_eq!(
+        model.insert_columns(0, 1, 0),
+        Err("Cannot add a negative number of cells :)".to_string())
+    );
+
+    // Overflow to the right.
+    let too_many = LAST_COLUMN; // Ensures max_column + too_many > LAST_COLUMN
+    assert_eq!(
+        model.insert_columns(0, 1, too_many),
+        Err("Cannot shift cells because that would delete cells at the end of a row".to_string())
+    );
+}
+
+#[test]
+fn delete_multiple_rows_shifts_cells_upwards() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+
+    // Populate rows 10..14 (to be deleted) so that the diff builder does not fail.
+    for r in 10..15 {
+        model.set_user_input(0, r, 1, "del").unwrap();
+    }
+    // Place a value below the deletion range.
+    model.set_user_input(0, 20, 1, "keep").unwrap();
+
+    // Delete 5 rows starting at row 10.
+    assert!(model.delete_rows(0, 10, 5).is_ok());
+
+    // The value originally at row 20 should now be at row 15.
+    assert_eq!(model.get_formatted_cell_value(0, 15, 1).unwrap(), "keep");
+
+    // Undo / redo cycle.
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 20, 1).unwrap(), "keep");
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 15, 1).unwrap(), "keep");
+}
+
+#[test]
+fn delete_rows_errors() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+
+    // Negative or zero counts are rejected.
+    assert_eq!(
+        model.delete_rows(0, 1, -3),
+        Err("Please use insert rows instead".to_string())
+    );
+    assert_eq!(
+        model.delete_rows(0, 1, 0),
+        Err("Please use insert rows instead".to_string())
+    );
+}
+
+#[test]
+fn delete_multiple_columns_shifts_cells_left() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+
+    // Place a value to the right of the deletion range.
+    model.set_user_input(0, 1, 15, "88").unwrap();
+
+    // Delete 4 columns starting at column 5.
+    assert!(model.delete_columns(0, 5, 4).is_ok());
+
+    // The value originally at column 15 should now be at column 11.
+    assert_eq!(model.get_formatted_cell_value(0, 1, 11).unwrap(), "88");
+
+    // Undo / redo cycle.
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 15).unwrap(), "88");
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 11).unwrap(), "88");
+}
+
+#[test]
+fn delete_columns_errors() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+
+    // Negative or zero counts are rejected.
+    assert_eq!(
+        model.delete_columns(0, 1, -4),
+        Err("Please use insert columns instead".to_string())
+    );
+    assert_eq!(
+        model.delete_columns(0, 1, 0),
+        Err("Please use insert columns instead".to_string())
+    );
+}

base/src/test/user_model/test_paste_csv.rs

@@ -24,6 +24,7 @@ fn csv_paste() {
         model.get_formatted_cell_value(0, 7, 7),
         Ok("21".to_string())
     );
+    assert_eq!([4, 2, 5, 4], model.get_selected_view().range);
 }
 
 #[test]
@@ -45,6 +46,7 @@ fn csv_paste_formula() {
         model.get_formatted_cell_value(0, 1, 1),
         Ok("2022".to_string())
     );
+    assert_eq!([1, 1, 1, 1], model.get_selected_view().range);
 }
 
 #[test]
@@ -69,6 +71,7 @@ fn tsv_crlf_paste() {
         model.get_formatted_cell_value(0, 7, 7),
         Ok("21".to_string())
     );
+    assert_eq!([4, 2, 5, 4], model.get_selected_view().range);
 }
 
 #[test]
@@ -164,7 +167,7 @@ fn copy_paste_internal() {
     let copy = model.copy_to_clipboard().unwrap();
     assert_eq!(
         copy.csv,
-        "42\t127\n\"A season of faith\t \"\"perfection\"\"\"\t\n"
+        "42\t127\n\"A season of faith\t \"\"perfection\"\"\""
     );
     assert_eq!(copy.range, (1, 1, 2, 2));
 

base/src/test/user_model/test_row_column.rs

@@ -14,7 +14,7 @@ fn simple_insert_row() {
     for row in 1..5 {
         assert!(model.set_user_input(sheet, row, column, "123").is_ok());
     }
-    assert!(model.insert_row(sheet, 3).is_ok());
+    assert!(model.insert_rows(sheet, 3, 1).is_ok());
     assert_eq!(
         model.get_formatted_cell_value(sheet, 3, column).unwrap(),
         ""
@@ -40,7 +40,7 @@ fn simple_insert_column() {
     for column in 1..5 {
         assert!(model.set_user_input(sheet, row, column, "123").is_ok());
     }
-    assert!(model.insert_column(sheet, 3).is_ok());
+    assert!(model.insert_columns(sheet, 3, 1).is_ok());
     assert_eq!(model.get_formatted_cell_value(sheet, row, 3).unwrap(), "");
 
     assert!(model.undo().is_ok());
@@ -62,7 +62,7 @@ fn simple_delete_column() {
         .set_columns_width(0, 5, 5, DEFAULT_COLUMN_WIDTH * 3.0)
         .unwrap();
 
-    model.delete_column(0, 5).unwrap();
+    model.delete_columns(0, 5, 1).unwrap();
 
     assert_eq!(model.get_formatted_cell_value(0, 2, 5), Ok("".to_string()));
     assert_eq!(model.get_column_width(0, 5), Ok(DEFAULT_COLUMN_WIDTH));
@@ -92,20 +92,20 @@ fn delete_column_errors() {
     let model = new_empty_model();
     let mut model = UserModel::from_model(model);
     assert_eq!(
-        model.delete_column(1, 1),
+        model.delete_columns(1, 1, 1),
         Err("Invalid sheet index".to_string())
     );
 
     assert_eq!(
-        model.delete_column(0, 0),
+        model.delete_columns(0, 0, 1),
         Err("Column number '0' is not valid.".to_string())
     );
     assert_eq!(
-        model.delete_column(0, LAST_COLUMN + 1),
+        model.delete_columns(0, LAST_COLUMN + 1, 1),
-        Err("Column number '16385' is not valid.".to_string())
+        Err(format!("Column number '{}' is not valid.", LAST_COLUMN + 1))
     );
 
-    assert_eq!(model.delete_column(0, LAST_COLUMN), Ok(()));
+    assert_eq!(model.delete_columns(0, LAST_COLUMN, 1), Ok(()));
 }
 
 #[test]
@@ -119,7 +119,7 @@ fn simple_delete_row() {
         .set_rows_height(0, 15, 15, DEFAULT_ROW_HEIGHT * 3.0)
         .unwrap();
 
-    model.delete_row(0, 15).unwrap();
+    model.delete_rows(0, 15, 1).unwrap();
 
     assert_eq!(model.get_formatted_cell_value(0, 15, 6), Ok("".to_string()));
     assert_eq!(model.get_row_height(0, 15), Ok(DEFAULT_ROW_HEIGHT));
@@ -150,7 +150,7 @@ fn simple_delete_row_no_style() {
     let mut model = UserModel::from_model(model);
     model.set_user_input(0, 15, 4, "3").unwrap();
     model.set_user_input(0, 15, 6, "=D15*2").unwrap();
-    model.delete_row(0, 15).unwrap();
+    model.delete_rows(0, 15, 1).unwrap();
 
     assert_eq!(model.get_formatted_cell_value(0, 15, 6), Ok("".to_string()));
 }
@@ -180,14 +180,14 @@ fn insert_row_evaluates() {
     model.set_user_input(0, 1, 1, "42").unwrap();
     model.set_user_input(0, 1, 2, "=A1*2").unwrap();
 
-    assert!(model.insert_row(0, 1).is_ok());
+    assert!(model.insert_rows(0, 1, 1).is_ok());
     assert_eq!(model.get_formatted_cell_value(0, 2, 2).unwrap(), "84");
     model.undo().unwrap();
     assert_eq!(model.get_formatted_cell_value(0, 1, 2).unwrap(), "84");
     model.redo().unwrap();
     assert_eq!(model.get_formatted_cell_value(0, 2, 2).unwrap(), "84");
 
-    model.delete_row(0, 1).unwrap();
+    model.delete_rows(0, 1, 1).unwrap();
     assert_eq!(model.get_formatted_cell_value(0, 1, 2).unwrap(), "84");
     assert_eq!(model.get_cell_content(0, 1, 2).unwrap(), "=A1*2");
 }
@@ -199,7 +199,7 @@ fn insert_column_evaluates() {
     model.set_user_input(0, 1, 1, "42").unwrap();
     model.set_user_input(0, 10, 1, "=A1*2").unwrap();
 
-    assert!(model.insert_column(0, 1).is_ok());
+    assert!(model.insert_columns(0, 1, 1).is_ok());
     assert_eq!(model.get_formatted_cell_value(0, 10, 2).unwrap(), "84");
 
     model.undo().unwrap();
@@ -207,7 +207,7 @@ fn insert_column_evaluates() {
     model.redo().unwrap();
     assert_eq!(model.get_formatted_cell_value(0, 10, 2).unwrap(), "84");
 
-    model.delete_column(0, 1).unwrap();
+    model.delete_columns(0, 1, 1).unwrap();
     assert_eq!(model.get_formatted_cell_value(0, 10, 1).unwrap(), "84");
     assert_eq!(model.get_cell_content(0, 10, 1).unwrap(), "=A1*2");
 }

base/src/test/user_model/test_view.rs

@@ -55,7 +55,7 @@ fn set_the_range_does_not_set_the_cell() {
     assert_eq!(
         model.set_selected_range(5, 4, 10, 6),
         Err(
-            "The selected cells is not in one of the corners. Row: '1' and row range '(5, 10)'"
+            "The selected cell is not in one of the corners. Row: '1' and row range '(5, 10)'"
                 .to_string()
         )
     );