UPDATE: Adds ACCRINT and ACCRINTM

* update: adds unit test for EVEN and ODD functions

* update: adds xlsx test for EVEN and ODD functions

* update: adds EVEN and ODD doc pages

* update: Math and Trigonometry main page links to new functions

* update: changes to functions badge type in main Math and Trigonometry page

.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

@@ -414,7 +414,7 @@ dependencies = [
 
 [[package]]
 name = "ironcalc"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "bitcode",
  "chrono",
@@ -430,14 +430,13 @@ 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",
@@ -448,7 +447,7 @@ dependencies = [
 
 [[package]]
 name = "ironcalc_nodejs"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "ironcalc",
  "napi",
@@ -721,11 +720,10 @@ 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 +737,9 @@ 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 +747,9 @@ 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 +757,9 @@ 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 +769,9 @@ 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 +782,9 @@ dependencies = [
 
 [[package]]
 name = "pyroncalc"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
+ "bitcode",
  "ironcalc",
  "pyo3",
  "serde",
@@ -872,6 +871,12 @@ 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"
@@ -979,9 +984,9 @@ 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 +1075,7 @@ checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
 [[package]]
 name = "wasm"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "ironcalc_base",
  "serde",
@@ -1081,23 +1086,24 @@ 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 +1124,9 @@ 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 +1134,9 @@ 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 +1147,12 @@ 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"
@@ -17,7 +17,6 @@ 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"
 

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

@@ -159,7 +159,7 @@ 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/cell.rs

@@ -89,8 +89,6 @@ impl Cell {
             Cell::CellFormulaNumber { s, .. } => *s = style,
             Cell::CellFormulaString { s, .. } => *s = style,
             Cell::CellFormulaError { s, .. } => *s = style,
-            // Should we throw an error here?
-            Cell::Merged { .. } => {}
         };
     }
 
@@ -106,8 +104,6 @@ impl Cell {
             Cell::CellFormulaNumber { s, .. } => *s,
             Cell::CellFormulaString { s, .. } => *s,
             Cell::CellFormulaError { s, .. } => *s,
-            // A merged cell has no style
-            Cell::Merged { .. } => 0,
         }
     }
 
@@ -123,7 +119,6 @@ impl Cell {
             Cell::CellFormulaNumber { .. } => CellType::Number,
             Cell::CellFormulaString { .. } => CellType::Text,
             Cell::CellFormulaError { .. } => CellType::ErrorValue,
-            Cell::Merged { .. } => CellType::Number,
         }
     }
 
@@ -161,7 +156,6 @@ impl Cell {
                 let v = ei.to_localized_error_string(language);
                 CellValue::String(v)
             }
-            Cell::Merged { .. } => CellValue::None,
         }
     }
 

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(self.set_error(&format!("Failed to parse to double: {}", chars), position))
-            }
+            Err(_) => 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
-                                .set_error(&format!("Failed parsing row {}", row_left), position))
+                            return Err(
+                                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::Error(kind) => format!("{}", kind),
+        ArrayNode::String(value) => format!("\"{value}\""),
+        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> =
-    Lazy::new(|| Regex::new(r":[A-Z]*[0-9]*$").expect("Regex is known to be valid"));
+fn get_re() -> &'static Regex {
+    RANGE_REFERENCE_REGEX
+        .get_or_init(|| Regex::new(r":[A-Z]*[0-9]*$").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 +832,52 @@ 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::Accrint => args_signature_scalars(arg_count, 6, 2),
+        Function::Accrintm => args_signature_scalars(arg_count, 4, 1),
     }
 }
 
@@ -816,6 +916,9 @@ 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 +989,27 @@ 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 +1098,50 @@ 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::Accrint => scalar_arguments(args),
+        Function::Accrintm => scalar_arguments(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
-                            && column > *move_column
-                            && column <= *move_column + *delta)
-                            || (*delta < 0
-                                && column < *move_column
-                                && column >= *move_column + *delta)
-                        {
-                            column -= *delta;
+                        } else if *delta > 0 {
+                            // Moving the column to the right
+                            if column > *move_column && column <= *move_column + *delta {
+                                // Intermediate columns move left by one position
+                                column -= 1;
+                            }
+                        } else if *delta < 0 {
+                            // 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!(
-            "{}{}{}",
-            stringify(left, context, displace_data, export_to_excel),
-            kind,
-            stringify(right, context, displace_data, export_to_excel)
-        ),
+        OpSumKind { kind, left, right } => {
+            let left_str = 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
+            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!(
-                    "({})",
-                    stringify(left, context, displace_data, export_to_excel)
-                ),
-                CompareKind { .. } => format!(
+                OpSumKind { .. } | CompareKind { .. } => format!(
                     "({})",
                     stringify(left, context, displace_data, export_to_excel)
                 ),
                 _ => stringify(left, context, displace_data, export_to_excel),
             };
             let y = match **right {
-                OpSumKind { .. } => format!(
-                    "({})",
-                    stringify(right, context, displace_data, export_to_excel)
-                ),
-                CompareKind { .. } => format!(
-                    "({})",
-                    stringify(right, context, displace_data, export_to_excel)
-                ),
-                OpProductKind { .. } => format!(
+                OpSumKind { .. } | CompareKind { .. } | 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)
@@ -582,17 +612,49 @@ 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 => {
-                format!(
-                    "-{}",
-                    stringify(right, context, displace_data, export_to_excel)
-                )
+                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

@@ -259,15 +259,23 @@ 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;
+        }
+    }
+    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
+        return true;
     }
-    // TODO:
-    // cell reference in A1 notation, e.g. B1048576 is quoted, B1048577 is not
-    // cell reference in R1C1 notation, e.g. RC, RC2, R5C, R-4C, RC-8, R, C
-    // integers
     false
 }
 
@@ -279,3 +287,32 @@ 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

@@ -211,4 +211,6 @@ fn test_names() {
     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 {}",
-            MINIMUM_DATE_SERIAL_NUMBER
+            "Excel date must be greater than {MINIMUM_DATE_SERIAL_NUMBER}"
         ));
     };
     if days > MAXIMUM_DATE_SERIAL_NUMBER as i64 {
         return Err(format!(
-            "Excel date must be less than {}",
-            MAXIMUM_DATE_SERIAL_NUMBER
+            "Excel date must be less than {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

@@ -120,7 +120,7 @@ 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 +138,7 @@ 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 +154,72 @@ 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) {
-                Ok(d) => d,
-                Err(e) => {
-                    return Formatted {
-                        text: "#VALUE!".to_owned(),
-                        color: None,
-                        error: Some(e),
-                    }
-                }
-            };
+            let time_fract = value.fract();
+            let hours = (time_fract * 24.0).floor();
+            let minutes = ((time_fract * 24.0 - hours) * 60.0).floor();
+            let seconds = ((((time_fract * 24.0 - hours) * 60.0) - minutes) * 60.0).round();
+            let date = from_excel_date(value as i64).ok();
             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 => {
-                        let day = date.day() as usize;
-                        text = format!("{}{}", text, day);
-                    }
+                    TextToken::Day => match date {
+                        Some(date) => {
+                            let day = date.day() as usize;
+                            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 +227,16 @@ 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 +244,144 @@ 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 +393,7 @@ 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));
@@ -295,26 +441,26 @@ 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 +468,7 @@ 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 +493,7 @@ 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 +519,18 @@ 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 +546,7 @@ 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 +568,13 @@ 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 {
@@ -614,7 +767,7 @@ 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())));

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
-    MonthPadded,    // mm
+    Month,          // m (or minute)
+    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,
-                        2 => Token::MonthPadded,
+                        1 => Token::Month,       // (or minute)
+                        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) => {
@@ -236,12 +249,22 @@ impl Parser {
                     tokens.push(TextToken::MonthName);
                 }
                 Token::Month => {
-                    is_date = true;
-                    tokens.push(TextToken::Month);
+                    if is_time {
+                        // minute
+                        tokens.push(TextToken::Minute);
+                    } else {
+                        is_date = true;
+                        tokens.push(TextToken::Month);
+                    }
                 }
                 Token::MonthPadded => {
-                    is_date = true;
-                    tokens.push(TextToken::MonthPadded);
+                    if is_time {
+                        // minute padded
+                        tokens.push(TextToken::MinutePadded);
+                    } else {
+                        is_date = true;
+                        tokens.push(TextToken::MonthPadded);
+                    }
                 }
                 Token::MonthLetter => {
                     is_date = true;
@@ -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/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/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()
@@ -1830,4 +1830,14 @@ impl Model {
 
         CalcResult::Number(rate * (cost - result))
     }
+
+    // ACCRINT(issue, first_interest, settlement, rate, par, frequency, [basis], [calc_method])
+    pub(crate) fn fn_accrint(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        todo!()
+    }
+
+    // ACCRINTM(issue, settlement, rate, par, [basis])
+    pub(crate) fn fn_accrintm(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult {
+        todo!()
+    }
 }

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/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

@@ -16,6 +16,7 @@ mod information;
 mod logical;
 mod lookup_and_reference;
 mod macros;
+mod math_util;
 mod mathematical;
 mod statistical;
 mod subtotal;
@@ -54,6 +55,9 @@ pub enum Function {
     Columns,
     Cos,
     Cosh,
+    Log,
+    Log10,
+    Ln,
     Max,
     Min,
     Pi,
@@ -73,6 +77,43 @@ 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 +134,11 @@ pub enum Function {
     Sheet,
     Type,
 
+    Sheets,
+    N,
+    Cell,
+    Info,
+
     // Lookup and reference
     Hlookup,
     Index,
@@ -145,15 +191,34 @@ 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
+    Accrint,
+    Accrintm,
     Cumipmt,
     Cumprinc,
     Db,
@@ -250,7 +315,7 @@ pub enum Function {
 }
 
 impl Function {
-    pub fn into_iter() -> IntoIter<Function, 195> {
+    pub fn into_iter() -> IntoIter<Function, 258> {
         [
             Function::And,
             Function::False,
@@ -277,15 +342,50 @@ 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 +456,26 @@ 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 +564,17 @@ 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::Accrint,
+            Function::Accrintm,
         ]
         .into_iter()
     }
@@ -488,6 +616,19 @@ 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(),
+
             _ => self.to_string(),
         }
     }
@@ -510,30 +651,61 @@ 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" => Some(Function::Acot),
+            "COTH" => Some(Function::Coth),
+            "COT" => Some(Function::Cot),
+            "CSC" => Some(Function::Csc),
+            "CSCH" => Some(Function::Csch),
+            "SEC" => Some(Function::Sec),
+            "SECH" => Some(Function::Sech),
+            "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 +717,9 @@ 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 +796,26 @@ 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 +907,14 @@ 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),
+            "ACCRINT" => Some(Function::Accrint),
+            "ACCRINTM" => Some(Function::Accrintm),
+
             _ => None,
         }
     }
@@ -734,6 +934,9 @@ 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 +949,14 @@ 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 +1021,6 @@ 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 +1038,26 @@ 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 +1145,44 @@ 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::Accrint => write!(f, "ACCRINT"),
+            Function::Accrintm => write!(f, "ACCRINTM"),
         }
     }
 }
@@ -948,7 +1211,6 @@ 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 +1222,27 @@ 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 +1254,6 @@ 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 +1267,6 @@ 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 +1284,6 @@ 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 +1301,6 @@ 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 +1313,31 @@ 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 +1371,6 @@ 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 +1425,50 @@ 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::Accrint => self.fn_accrint(args, cell),
+            Function::Accrintm => self.fn_accrintm(args, cell),
         }
     }
 }
@@ -1214,7 +1523,7 @@ 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::Number(value) => result = format!("{}{}", result, value),
+                CalcResult::String(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);
-                                }
-                                CalcResult::Number(value) => {
-                                    result = format!("{}{}", result, 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

@@ -110,7 +110,7 @@ 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(|| {
-    bitcode::decode(include_bytes!("language.bin")).expect("Failed parsing language file")
-});
+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(language)
+        .ok_or_else(|| format!("Language is not supported: '{id}'"))
 }

base/src/lib.rs

@@ -59,7 +59,6 @@ pub mod mock_time;
 
 pub use model::get_milliseconds_since_epoch;
 pub use model::Model;
-pub use model::CellStructure;
 pub use user_model::BorderArea;
 pub use user_model::ClipboardData;
 pub use user_model::UserModel;

base/src/locale/mod.rs

@@ -1,7 +1,6 @@
-use bitcode::{Decode, Encode};
-use once_cell::sync::Lazy;
+use std::{collections::HashMap, sync::OnceLock};
 
-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>> =
-    Lazy::new(|| bitcode::decode(include_bytes!("locales.bin")).expect("Failed parsing locale"));
+fn get_locales() -> &'static HashMap<String, 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
-    let locale = LOCALES.get(id).ok_or("Invalid locale")?;
-    Ok(locale)
+    get_locales()
+        .get(id)
+        .ok_or_else(|| format!("Invalid locale: '{id}'"))
 }

base/src/model.rs

@@ -31,7 +31,6 @@ use crate::{
 };
 
 use chrono_tz::Tz;
-use serde::{Deserialize, Serialize};
 
 #[cfg(test)]
 pub use crate::mock_time::get_milliseconds_since_epoch;
@@ -73,27 +72,6 @@ pub(crate) enum CellState {
     Evaluating,
 }
 
-/// Cell structure indicates if the cell is part of a merged cell or not
-#[derive(Clone, Serialize, Deserialize)]
-pub enum CellStructure {
-    /// The cell is not part of a merged cell
-    Simple,
-    /// The cell is part of a merged cell, and teh root cell is (row, column)
-    Merged {
-        /// Row of the root cell
-        row: i32,
-        /// Column of the root cell
-        column: i32,
-    },
-    /// The cell is the root of a merged cell of dimensions (width, height)
-    MergedRoot {
-        /// Width of the merged cell
-        width: i32,
-        /// Height of the merged cell
-        height: i32,
-    },
-}
-
 /// A parsed formula for a defined name
 #[derive(Clone)]
 pub(crate) enum ParsedDefinedName {
@@ -128,15 +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,
 }
 
@@ -237,7 +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),
@@ -377,7 +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 {
@@ -397,7 +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, _)) => {
@@ -413,26 +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);
@@ -509,7 +487,7 @@ impl Model {
             } => CalcResult::new_error(
                 Error::ERROR,
                 cell,
-                format!("Error parsing {}: {}", formula, message),
+                format!("Error parsing {formula}: {message}"),
             ),
             EmptyArgKind => CalcResult::EmptyArg,
             ImplicitIntersection {
@@ -522,7 +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:?}"),
                         ),
                     }
                 }
@@ -719,7 +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
@@ -773,7 +751,6 @@ impl Model {
                     }
                 }
             }
-            Merged { .. } => CalcResult::EmptyCell,
         }
     }
 
@@ -1050,7 +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());
@@ -1064,7 +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 {
@@ -1084,7 +1061,7 @@ impl Model {
                     column_delta: target.column - source.column,
                 },
             );
-            Ok(format!("={}", formula_str))
+            Ok(format!("={formula_str}"))
         } else {
             Ok(value.to_string())
         }
@@ -1461,10 +1438,6 @@ impl Model {
         value: String,
     ) -> Result<(), String> {
         // If value starts with "'" then we force the style to be quote_prefix
-        let cell = self.workbook.worksheet(sheet)?.cell(row, column);
-        if matches!(cell, Some(Cell::Merged { .. })) {
-            return Err("Cannot set value on merged cell".to_string());
-        }
         let style_index = self.get_cell_style_index(sheet, row, column)?;
         if let Some(new_value) = value.strip_prefix('\'') {
             // First check if it needs quoting
@@ -1565,7 +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,
@@ -2285,91 +2258,6 @@ impl Model {
     pub fn delete_row_style(&mut self, sheet: u32, row: i32) -> Result<(), String> {
         self.workbook.worksheet_mut(sheet)?.delete_row_style(row)
     }
-
-    /// Returns the geometric structure of a cell
-    pub fn get_cell_structure(
-        &self,
-        sheet: u32,
-        row: i32,
-        column: i32,
-    ) -> Result<CellStructure, String> {
-        let worksheet = self.workbook.worksheet(sheet)?;
-        worksheet.get_cell_structure(row, column)
-    }
-
-    /// Merges cells
-    pub fn merge_cells(
-        &mut self,
-        sheet: u32,
-        row: i32,
-        column: i32,
-        width: i32,
-        height: i32,
-    ) -> Result<(), String> {
-        let worksheet = self.workbook.worksheet_mut(sheet)?;
-        let sheet_data = &mut worksheet.sheet_data;
-        // First check that it is possible to merge the cells
-        for r in row..(row + height) {
-            for c in column..(column + width) {
-                if let Some(Cell::Merged { .. }) =
-                    sheet_data.get(&r).and_then(|row_data| row_data.get(&c))
-                {
-                    return Err("Cannot merge cells".to_string());
-                }
-            }
-        }
-        worksheet
-            .merged_cells
-            .insert((row, column), (width, height));
-        for r in row..(row + height) {
-            for c in column..(column + width) {
-                // We remove everything except the "root" cell:
-                if r == row && c == column {
-                    continue;
-                }
-                if let Some(row_data) = sheet_data.get_mut(&r) {
-                    row_data.remove(&c);
-                    row_data.insert(c, Cell::Merged { r: row, c: column });
-                } else {
-                    let mut row_data = HashMap::new();
-                    row_data.insert(c, Cell::Merged { r: row, c: column });
-                    sheet_data.insert(r, row_data);
-                }
-            }
-        }
-        Ok(())
-    }
-
-    /// Unmerges cells
-    pub fn unmerge_cells(&mut self, sheet: u32, row: i32, column: i32) -> Result<(), String> {
-        let s = self.get_cell_style_index(sheet, row, column)?;
-        let worksheet = self.workbook.worksheet_mut(sheet)?;
-        let sheet_data = &mut worksheet.sheet_data;
-        let (width, height) = match worksheet.merged_cells.get(&(row, column)) {
-            Some((w, h)) => (*w, *h),
-            None => return Ok(()),
-        };
-        worksheet.merged_cells.remove(&(row, column));
-        for r in row..(row + width) {
-            for c in column..(column + height) {
-                // We remove everything except the "root" cell:
-                if r == row && c == column {
-                    continue;
-                }
-                if let Some(row_data) = sheet_data.get_mut(&r) {
-                    row_data.remove(&c);
-                    if s != 0 {
-                        row_data.insert(c, Cell::EmptyCell { s });
-                    }
-                } else if s != 0 {
-                    let mut row_data = HashMap::new();
-                    row_data.insert(c, Cell::EmptyCell { s });
-                    sheet_data.insert(r, row_data);
-                }
-            }
-        }
-        Ok(())
-    }
 }
 
 #[cfg(test)]

base/src/new_empty.rs

@@ -58,10 +58,10 @@ impl Model {
             rows: vec![],
             comments: vec![],
             dimension: "A1".to_string(),
+            merge_cells: vec![],
             name: name.to_string(),
             shared_formulas: vec![],
             sheet_data: Default::default(),
-            merged_cells: HashMap::new(),
             sheet_id,
             state: SheetState::Visible,
             color: Default::default(),
@@ -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

@@ -126,7 +126,7 @@ pub fn to_precision_str(value: f64, precision: usize) -> String {
     let exponent = value.abs().log10().floor();
     let base = value / 10.0_f64.powf(exponent);
     let base = format!("{0:.1$}", base, precision - 1);
-    let value = format!("{}e{}", base, exponent).parse::<f64>().unwrap_or({
+    let value = format!("{base}e{exponent}").parse::<f64>().unwrap_or({
         // TODO: do this in a way that does not require a possible error
         0.0
     });

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/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;
@@ -54,15 +61,23 @@ mod test_number_format;
 mod test_arrays;
 mod test_escape_quotes;
 mod test_extend;
+mod test_fn_accrint;
 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_networkdays;
 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_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 +221,382 @@ 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("A5", "=YEARFRAC(44926,44561,1)"); // Reverse = negative
+    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("A5"), *"-1"); // Negative
+    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_fn_accrint.rs

@@ -0,0 +1,23 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn fn_average_accrint_simple_cases() {
+    let mut model = new_empty_model();
+    // ACCRINT(issue, first_interest, settlement, rate, par, frequency, [basis], [calc_method])
+    model._set("A1", "=ACCRINT(39508, 39691, 39569, 0.1, 1000, 2, 0)");
+    model._set(
+        "A2",
+        "=ACCRINT(DATE(2008, 3, 5), 39691, 39569, 0.1, 1000, 2, 0, FALSE)",
+    );
+    model._set(
+        "A3",
+        "=ACCRINT(DATE(2008, 4, 5), 39691, 39569, 0.1, 1000, 2, 0, TRUE)",
+    );
+    model.evaluate();
+
+    assert_eq!(model._get_text("A1"), *"16.666666667");
+    assert_eq!(model._get_text("A2"), *"15.555555556");
+    assert_eq!(model._get_text("A3"), *"7.222222222");
+}

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_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_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_styles.rs

@@ -62,3 +62,17 @@ fn test_create_named_style() {
     let style = model.get_style_for_cell(0, 1, 1).unwrap();
     assert!(style.font.b);
 }
+
+#[test]
+fn empty_models_have_two_fills() {
+    let model = new_empty_model();
+    assert_eq!(model.workbook.styles.fills.len(), 2);
+    assert_eq!(
+        model.workbook.styles.fills[0].pattern_type,
+        "none".to_string()
+    );
+    assert_eq!(
+        model.workbook.styles.fills[1].pattern_type,
+        "gray125".to_string()
+    );
+}

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");
+    }
+
+    // Negative symmetric of 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: {}",
-                            sheet,
-                            row,
-                            column
+                            "(Top). Sheet: {sheet}, row: {row}, column: {column}"
                         );
                     }
                 }
@@ -65,10 +62,7 @@ fn check_borders(model: &UserModel) {
                         assert_eq!(
                             Some(right_border),
                             right_cell_style.border.left,
-                            "(Right). Sheet: {}, row: {}, column: {}",
-                            sheet,
-                            row,
-                            column
+                            "(Right). Sheet: {sheet}, row: {row}, column: {column}"
                         );
                     }
                 }
@@ -80,10 +74,7 @@ fn check_borders(model: &UserModel) {
                         assert_eq!(
                             Some(bottom_border),
                             bottom_cell_style.border.top,
-                            "(Bottom). Sheet: {}, row: {}, column: {}",
-                            sheet,
-                            row,
-                            column
+                            "(Bottom). Sheet: {sheet}, row: {row}, column: {column}"
                         );
                     }
                 }
@@ -94,10 +85,7 @@ fn check_borders(model: &UserModel) {
                         assert_eq!(
                             Some(left_border),
                             left_cell_style.border.right,
-                            "(Left). Sheet: {}, row: {}, column: {}",
-                            sheet,
-                            row,
-                            column
+                            "(Left). Sheet: {sheet}, row: {row}, column: {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_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_row(0, 3).unwrap();
+    model1.insert_rows(0, 3, 1).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),
-        Err("Column number '16385' is not valid.".to_string())
+        model.delete_columns(0, LAST_COLUMN + 1, 1),
+        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()
         )
     );

base/src/test/user_model/util.rs

@@ -11,11 +11,10 @@ impl UserModel {
             r##"{{
                 "item": {{
                     "style": "thin",
-                    "color": "{}"
+                    "color": "{color}"
                 }},
                 "type": "All"
-            }}"##,
-            color
+            }}"##
         ))
         .unwrap();
         let range = &Area {
@@ -40,11 +39,10 @@ impl UserModel {
             r##"{{
                 "item": {{
                     "style": "thin",
-                    "color": "{}"
+                    "color": "{color}"
                 }},
-                "type": "{}"
-            }}"##,
-            color, kind
+                "type": "{kind}"
+            }}"##
         ))
         .unwrap();
         let range = &Area {

base/src/test/util.rs

@@ -13,7 +13,7 @@ impl Model {
         if cell.contains('!') {
             self.parse_reference(cell).unwrap()
         } else {
-            self.parse_reference(&format!("Sheet1!{}", cell)).unwrap()
+            self.parse_reference(&format!("Sheet1!{cell}")).unwrap()
         }
     }
     pub fn _set(&mut self, cell: &str, value: &str) {

base/src/types.rs

@@ -110,7 +110,7 @@ pub struct Worksheet {
     pub sheet_id: u32,
     pub state: SheetState,
     pub color: Option<String>,
-    pub merged_cells: HashMap<(i32, i32), (i32, i32)>,
+    pub merge_cells: Vec<String>,
     pub comments: Vec<Comment>,
     pub frozen_rows: i32,
     pub frozen_columns: i32,
@@ -217,10 +217,7 @@ pub enum Cell {
         // Error Message: "Not implemented function"
         m: String,
     },
-    Merged {
-        r: i32,
-        c: i32,
-    }, // TODO: Array formulas
+    // TODO: Array formulas
 }
 
 impl Default for Cell {
@@ -306,7 +303,14 @@ impl Default for Styles {
         Styles {
             num_fmts: vec![],
             fonts: vec![Default::default()],
-            fills: vec![Default::default()],
+            fills: vec![
+                Default::default(),
+                Fill {
+                    pattern_type: "gray125".to_string(),
+                    fg_color: None,
+                    bg_color: None,
+                },
+            ],
             borders: vec![Default::default()],
             cell_style_xfs: vec![Default::default()],
             cell_xfs: vec![Default::default()],

base/src/user_model/common.rs

@@ -11,10 +11,10 @@ use crate::{
         types::{Area, CellReferenceIndex},
         utils::{is_valid_column_number, is_valid_row},
     },
-    model::{CellStructure, Model},
+    model::Model,
     types::{
-        Alignment, BorderItem, CellType, Col, HorizontalAlignment, SheetProperties, SheetState,
-        Style, VerticalAlignment,
+        Alignment, BorderItem, Cell, CellType, Col, HorizontalAlignment, SheetProperties,
+        SheetState, Style, VerticalAlignment,
     },
     utils::is_valid_hex_color,
 };
@@ -627,6 +627,7 @@ impl UserModel {
             }
         }
         self.push_diff_list(diff_list);
+        self.evaluate_if_not_paused();
         Ok(())
     }
 
@@ -656,11 +657,16 @@ impl UserModel {
             }
         }
         self.push_diff_list(diff_list);
+        self.evaluate_if_not_paused();
         Ok(())
     }
 
-    fn clear_column_formatting(&mut self, sheet: u32, column: i32) -> Result<(), String> {
-        let mut diff_list = Vec::new();
+    fn clear_column_formatting(
+        &mut self,
+        sheet: u32,
+        column: i32,
+        diff_list: &mut Vec<Diff>,
+    ) -> Result<(), String> {
         let old_value = self.model.get_column_style(sheet, column)?;
         self.model.delete_column_style(sheet, column)?;
         diff_list.push(Diff::DeleteColumnStyle {
@@ -739,12 +745,15 @@ impl UserModel {
                 }
             }
         }
-        self.push_diff_list(diff_list);
         Ok(())
     }
 
-    fn clear_row_formatting(&mut self, sheet: u32, row: i32) -> Result<(), String> {
-        let mut diff_list = Vec::new();
+    fn clear_row_formatting(
+        &mut self,
+        sheet: u32,
+        row: i32,
+        diff_list: &mut Vec<Diff>,
+    ) -> Result<(), String> {
         let old_value = self.model.get_row_style(sheet, row)?;
         self.model.delete_row_style(sheet, row)?;
         diff_list.push(Diff::DeleteRowStyle {
@@ -791,8 +800,6 @@ impl UserModel {
                 }
             }
         }
-        self.push_diff_list(diff_list);
-
         Ok(())
     }
 
@@ -803,19 +810,21 @@ impl UserModel {
     /// * [UserModel::range_clear_contents]
     pub fn range_clear_formatting(&mut self, range: &Area) -> Result<(), String> {
         let sheet = range.sheet;
+        let mut diff_list = Vec::new();
         if range.row == 1 && range.height == LAST_ROW {
             for column in range.column..range.column + range.width {
-                self.clear_column_formatting(sheet, column)?;
+                self.clear_column_formatting(sheet, column, &mut diff_list)?;
             }
+            self.push_diff_list(diff_list);
             return Ok(());
         }
         if range.column == 1 && range.width == LAST_COLUMN {
             for row in range.row..range.row + range.height {
-                self.clear_row_formatting(sheet, row)?;
+                self.clear_row_formatting(sheet, row, &mut diff_list)?;
             }
+            self.push_diff_list(diff_list);
             return Ok(());
         }
-        let mut diff_list = Vec::new();
         for row in range.row..range.row + range.height {
             for column in range.column..range.column + range.width {
                 if let Some(old_style) = self.model.get_cell_style_or_none(sheet, row, column)? {
@@ -851,105 +860,184 @@ impl UserModel {
         Ok(())
     }
 
-    /// Inserts a row
+    /// Inserts `row_count` blank rows starting at `row` (both 0-based).
     ///
-    /// See also:
-    /// * [Model::insert_rows]
-    pub fn insert_row(&mut self, sheet: u32, row: i32) -> Result<(), String> {
-        let diff_list = vec![Diff::InsertRow { sheet, row }];
+    /// Parameters
+    /// * `sheet` – worksheet index.
+    /// * `row` – first row to insert.
+    /// * `row_count` – number of rows (> 0).
+    ///
+    /// History: the method pushes `row_count` [`crate::user_model::history::Diff::InsertRow`]
+    /// items **all using the same `row` index**.  Replaying those diffs (undo / redo)
+    /// is therefore immune to the row-shifts that happen after each individual
+    /// insertion.
+    ///
+    /// See also [`Model::insert_rows`].
+    pub fn insert_rows(&mut self, sheet: u32, row: i32, row_count: i32) -> Result<(), String> {
+        self.model.insert_rows(sheet, row, row_count)?;
+
+        let diff_list = vec![Diff::InsertRows {
+            sheet,
+            row,
+            count: row_count,
+        }];
         self.push_diff_list(diff_list);
-        self.model.insert_rows(sheet, row, 1)?;
         self.evaluate_if_not_paused();
         Ok(())
     }
 
-    /// Deletes a row
+    /// Inserts `column_count` blank columns starting at `column` (0-based).
     ///
-    /// See also:
-    /// * [Model::delete_rows]
-    pub fn delete_row(&mut self, sheet: u32, row: i32) -> Result<(), String> {
-        let mut row_data = None;
+    /// Parameters
+    /// * `sheet` – worksheet index.
+    /// * `column` – first column to insert.
+    /// * `column_count` – number of columns (> 0).
+    ///
+    /// History: pushes one [`crate::user_model::history::Diff::InsertColumn`]
+    /// per inserted column, all with the same `column` value, preventing index
+    /// drift when the diffs are reapplied.
+    ///
+    /// See also [`Model::insert_columns`].
+    pub fn insert_columns(
+        &mut self,
+        sheet: u32,
+        column: i32,
+        column_count: i32,
+    ) -> Result<(), String> {
+        self.model.insert_columns(sheet, column, column_count)?;
+
+        let diff_list = vec![Diff::InsertColumns {
+            sheet,
+            column,
+            count: column_count,
+        }];
+        self.push_diff_list(diff_list);
+        self.evaluate_if_not_paused();
+        Ok(())
+    }
+
+    /// Deletes `row_count` rows starting at `row`.
+    ///
+    /// History: a [`crate::user_model::history::Diff::DeleteRow`] is created for
+    /// each row, ordered **bottom → top**.  Undo therefore recreates rows from
+    /// top → bottom and redo removes them bottom → top, avoiding index drift.
+    ///
+    /// See also [`Model::delete_rows`].
+    pub fn delete_rows(&mut self, sheet: u32, row: i32, row_count: i32) -> Result<(), String> {
         let worksheet = self.model.workbook.worksheet(sheet)?;
-        for rd in &worksheet.rows {
-            if rd.r == row {
-                row_data = Some(rd.clone());
-                break;
+        let mut old_data = Vec::new();
+        // Collect data for all rows to be deleted
+        for r in row..row + row_count {
+            let mut row_data = None;
+            for rd in &worksheet.rows {
+                if rd.r == r {
+                    row_data = Some(rd.clone());
+                    break;
+                }
             }
+            let data = match worksheet.sheet_data.get(&r) {
+                Some(s) => s.clone(),
+                None => HashMap::new(),
+            };
+            old_data.push(RowData {
+                row: row_data,
+                data,
+            });
         }
-        let data = match worksheet.sheet_data.get(&row) {
-            Some(s) => s.clone(),
-            None => return Err(format!("Row number '{row}' is not valid.")),
-        };
-        let old_data = Box::new(RowData {
-            row: row_data,
-            data,
-        });
-        let diff_list = vec![Diff::DeleteRow {
+
+        self.model.delete_rows(sheet, row, row_count)?;
+
+        let diff_list = vec![Diff::DeleteRows {
             sheet,
             row,
+            count: row_count,
             old_data,
         }];
         self.push_diff_list(diff_list);
-        self.model.delete_rows(sheet, row, 1)?;
         self.evaluate_if_not_paused();
         Ok(())
     }
 
-    /// Inserts a column
+    /// Deletes `column_count` columns starting at `column`.
     ///
-    /// See also:
-    /// * [Model::insert_columns]
-    pub fn insert_column(&mut self, sheet: u32, column: i32) -> Result<(), String> {
-        let diff_list = vec![Diff::InsertColumn { sheet, column }];
-        self.push_diff_list(diff_list);
-        self.model.insert_columns(sheet, column, 1)?;
-        self.evaluate_if_not_paused();
-        Ok(())
-    }
-
-    /// Deletes a column
+    /// History: pushes one [`crate::user_model::history::Diff::DeleteColumn`]
+    /// per column, **right → left**, so replaying the list is always safe with
+    /// respect to index shifts.
     ///
-    /// See also:
-    /// * [Model::delete_columns]
-    pub fn delete_column(&mut self, sheet: u32, column: i32) -> Result<(), String> {
+    /// See also [`Model::delete_columns`].
+    pub fn delete_columns(
+        &mut self,
+        sheet: u32,
+        column: i32,
+        column_count: i32,
+    ) -> Result<(), String> {
         let worksheet = self.model.workbook.worksheet(sheet)?;
-        if !is_valid_column_number(column) {
-            return Err(format!("Column number '{column}' is not valid."));
-        }
-
-        let mut column_data = None;
-        for col in &worksheet.cols {
-            let min = col.min;
-            let max = col.max;
-            if column >= min && column <= max {
-                column_data = Some(Col {
-                    min: column,
-                    max: column,
-                    width: col.width,
-                    custom_width: col.custom_width,
-                    style: col.style,
-                });
-                break;
+        let mut old_data = Vec::new();
+        // Collect data for all columns to be deleted
+        for c in column..column + column_count {
+            let mut column_data = None;
+            for col in &worksheet.cols {
+                if c >= col.min && c <= col.max {
+                    column_data = Some(Col {
+                        min: c,
+                        max: c,
+                        width: col.width,
+                        custom_width: col.custom_width,
+                        style: col.style,
+                    });
+                    break;
+                }
             }
-        }
 
-        let mut data = HashMap::new();
-        for (row, row_data) in &worksheet.sheet_data {
-            if let Some(cell) = row_data.get(&column) {
-                data.insert(*row, cell.clone());
+            let mut data = HashMap::new();
+            for (row_idx, row_data) in &worksheet.sheet_data {
+                if let Some(cell) = row_data.get(&c) {
+                    data.insert(*row_idx, cell.clone());
+                }
             }
-        }
 
-        let diff_list = vec![Diff::DeleteColumn {
-            sheet,
-            column,
-            old_data: Box::new(ColumnData {
+            old_data.push(ColumnData {
                 column: column_data,
                 data,
-            }),
+            });
+        }
+
+        self.model.delete_columns(sheet, column, column_count)?;
+
+        let diff_list = vec![Diff::DeleteColumns {
+            sheet,
+            column,
+            count: column_count,
+            old_data,
         }];
         self.push_diff_list(diff_list);
-        self.model.delete_columns(sheet, column, 1)?;
+        self.evaluate_if_not_paused();
+        Ok(())
+    }
+
+    /// Moves a column horizontally and adjusts formulas
+    pub fn move_column_action(
+        &mut self,
+        sheet: u32,
+        column: i32,
+        delta: i32,
+    ) -> Result<(), String> {
+        let diff_list = vec![Diff::MoveColumn {
+            sheet,
+            column,
+            delta,
+        }];
+        self.push_diff_list(diff_list);
+        self.model.move_column_action(sheet, column, delta)?;
+        self.evaluate_if_not_paused();
+        Ok(())
+    }
+
+    /// Moves a row vertically and adjusts formulas
+    pub fn move_row_action(&mut self, sheet: u32, row: i32, delta: i32) -> Result<(), String> {
+        let diff_list = vec![Diff::MoveRow { sheet, row, delta }];
+        self.push_diff_list(diff_list);
+        self.model.move_row_action(sheet, row, delta)?;
         self.evaluate_if_not_paused();
         Ok(())
     }
@@ -1487,10 +1575,10 @@ impl UserModel {
             return Err(format!("Invalid row: '{first_row}'"));
         }
         if !is_valid_column_number(last_column) {
-            return Err(format!("Invalid column: '{}'", last_column));
+            return Err(format!("Invalid column: '{last_column}'"));
         }
         if !is_valid_row(last_row) {
-            return Err(format!("Invalid row: '{}'", last_row));
+            return Err(format!("Invalid row: '{last_row}'"));
         }
 
         if !is_valid_row(to_column) {
@@ -1595,6 +1683,66 @@ impl UserModel {
         Ok(self.model.workbook.worksheet(sheet)?.show_grid_lines)
     }
 
+    /// Returns the largest column in the row less than a column whose cell has a non empty value.
+    /// If there are none it returns `None`.
+    /// This is useful when rendering a part of a worksheet to know which cells spill over
+    pub fn get_last_non_empty_in_row_before_column(
+        &self,
+        sheet: u32,
+        row: i32,
+        column: i32,
+    ) -> Result<Option<i32>, String> {
+        let worksheet = self.model.workbook.worksheet(sheet)?;
+        let data = worksheet.sheet_data.get(&row);
+        if let Some(row_data) = data {
+            let mut last_column = None;
+            let mut columns: Vec<i32> = row_data.keys().copied().collect();
+            columns.sort_unstable();
+            for col in columns {
+                if col < column {
+                    if let Some(cell) = worksheet.cell(row, col) {
+                        if matches!(cell, Cell::EmptyCell { .. }) {
+                            continue;
+                        }
+                    }
+                    last_column = Some(col);
+                }
+            }
+            Ok(last_column)
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Returns the smallest column in the row larger than "column" whose cell has a non empty value.
+    /// If there are none it returns `None`.
+    /// This is useful when rendering a part of a worksheet to know which cells spill over
+    pub fn get_first_non_empty_in_row_after_column(
+        &self,
+        sheet: u32,
+        row: i32,
+        column: i32,
+    ) -> Result<Option<i32>, String> {
+        let worksheet = self.model.workbook.worksheet(sheet)?;
+        let data = worksheet.sheet_data.get(&row);
+        if let Some(row_data) = data {
+            let mut columns: Vec<i32> = row_data.keys().copied().collect();
+            // We sort the keys to ensure we are going from left to right
+            columns.sort_unstable();
+            for col in columns {
+                if col > column {
+                    if let Some(cell) = worksheet.cell(row, col) {
+                        if matches!(cell, Cell::EmptyCell { .. }) {
+                            continue;
+                        }
+                    }
+                    return Ok(Some(col));
+                }
+            }
+        }
+        Ok(None)
+    }
+
     /// Returns a copy of the selected area
     pub fn copy_to_clipboard(&self) -> Result<Clipboard, String> {
         let selected_area = self.get_selected_view();
@@ -1623,18 +1771,18 @@ impl UserModel {
                 text_row.push(text);
             }
             wtr.write_record(text_row)
-                .map_err(|e| format!("Error while processing csv: {}", e))?;
+                .map_err(|e| format!("Error while processing csv: {e}"))?;
             data.insert(row, data_row);
         }
 
         let csv = String::from_utf8(
             wtr.into_inner()
-                .map_err(|e| format!("Processing error: '{}'", e))?,
+                .map_err(|e| format!("Processing error: '{e}'"))?,
         )
-        .map_err(|e| format!("Error converting from utf8: '{}'", e))?;
+        .map_err(|e| format!("Error converting from utf8: '{e}'"))?;
 
         Ok(Clipboard {
-            csv,
+            csv: csv.trim().to_string(),
             data,
             sheet,
             range: (row_start, column_start, row_end, column_end),
@@ -1802,7 +1950,7 @@ impl UserModel {
         }
         self.push_diff_list(diff_list);
         // select the pasted area
-        self.set_selected_range(area.row, area.column, row, column)?;
+        self.set_selected_range(area.row, area.column, row - 1, column - 1)?;
         self.evaluate_if_not_paused();
         Ok(())
     }
@@ -1869,57 +2017,6 @@ impl UserModel {
         Ok(())
     }
 
-    /// Merges cells
-    pub fn merge_cells(
-        &mut self,
-        sheet: u32,
-        row: i32,
-        column: i32,
-        width: i32,
-        height: i32,
-    ) -> Result<(), String> {
-        let old_data = Vec::new();
-        let diff_list = vec![Diff::MergeCells {
-            sheet,
-            row,
-            column,
-            width,
-            height,
-            old_data,
-        }];
-        self.model.merge_cells(sheet, row, column, width, height)?;
-        self.push_diff_list(diff_list);
-        self.evaluate_if_not_paused();
-        Ok(())
-    }
-
-    /// Check if cell is part of a merged cell
-    pub fn get_cell_structure(&self, sheet: u32, row: i32, column: i32) -> Result<CellStructure, String> {
-        self.model.get_cell_structure(sheet, row, column)
-    }
-
-    /// Unmerges cells
-    pub fn unmerge_cells(&mut self, sheet: u32, row: i32, column: i32) -> Result<(), String> {
-        let (width, height) = self
-            .model
-            .workbook
-            .worksheet(sheet)?
-            .merged_cells
-            .get(&(row, column))
-            .ok_or("No merged cells found")?;
-        let diff_list = vec![Diff::UnmergeCells {
-            sheet,
-            row,
-            column,
-            width: *width,
-            height: *height,
-        }];
-        self.model.unmerge_cells(sheet, row, column)?;
-        self.push_diff_list(diff_list);
-        self.evaluate_if_not_paused();
-        Ok(())
-    }
-
     // **** Private methods ****** //
 
     pub(crate) fn push_diff_list(&mut self, diff_list: DiffList) {
@@ -2018,45 +2115,56 @@ impl UserModel {
                         self.model.cell_clear_all(*sheet, *row, *column)?;
                     }
                 }
-                Diff::InsertRow { sheet, row } => {
-                    self.model.delete_rows(*sheet, *row, 1)?;
+                Diff::InsertRows { sheet, row, count } => {
+                    self.model.delete_rows(*sheet, *row, *count)?;
                     needs_evaluation = true;
                 }
-                Diff::DeleteRow {
+                Diff::DeleteRows {
                     sheet,
                     row,
+                    count: _,
                     old_data,
                 } => {
                     needs_evaluation = true;
-                    self.model.insert_rows(*sheet, *row, 1)?;
+                    self.model
+                        .insert_rows(*sheet, *row, old_data.len() as i32)?;
                     let worksheet = self.model.workbook.worksheet_mut(*sheet)?;
-                    if let Some(row_data) = old_data.row.clone() {
-                        worksheet.rows.push(row_data);
+                    for (i, row_data) in old_data.iter().enumerate() {
+                        let r = *row + i as i32;
+                        if let Some(row_style) = row_data.row.clone() {
+                            worksheet.rows.push(row_style);
+                        }
+                        worksheet.sheet_data.insert(r, row_data.data.clone());
                     }
-                    worksheet.sheet_data.insert(*row, old_data.data.clone());
                 }
-                Diff::InsertColumn { sheet, column } => {
-                    self.model.delete_columns(*sheet, *column, 1)?;
-                    needs_evaluation = true;
-                }
-                Diff::DeleteColumn {
+                Diff::InsertColumns {
                     sheet,
                     column,
+                    count,
+                } => {
+                    self.model.delete_columns(*sheet, *column, *count)?;
+                    needs_evaluation = true;
+                }
+                Diff::DeleteColumns {
+                    sheet,
+                    column,
+                    count: _,
                     old_data,
                 } => {
                     needs_evaluation = true;
-                    // inserts an empty column
-                    self.model.insert_columns(*sheet, *column, 1)?;
-                    // puts all the data back
+                    self.model
+                        .insert_columns(*sheet, *column, old_data.len() as i32)?;
                     let worksheet = self.model.workbook.worksheet_mut(*sheet)?;
-                    for (row, cell) in &old_data.data {
-                        worksheet.update_cell(*row, *column, cell.clone())?;
-                    }
-                    // makes sure that the width and style is correct
-                    if let Some(col) = &old_data.column {
-                        let width = col.width * constants::COLUMN_WIDTH_FACTOR;
-                        let style = col.style;
-                        worksheet.set_column_width_and_style(*column, width, style)?;
+                    for (i, col_data) in old_data.iter().enumerate() {
+                        let c = *column + i as i32;
+                        for (row, cell) in &col_data.data {
+                            worksheet.update_cell(*row, c, cell.clone())?;
+                        }
+                        if let Some(col) = &col_data.column {
+                            let width = col.width * constants::COLUMN_WIDTH_FACTOR;
+                            let style = col.style;
+                            worksheet.set_column_width_and_style(c, width, style)?;
+                        }
                     }
                 }
                 Diff::SetFrozenRowsCount {
@@ -2163,6 +2271,7 @@ impl UserModel {
                     worksheet.frozen_rows = old_data.frozen_rows;
                     worksheet.state = old_data.state.clone();
                     worksheet.color = old_data.color.clone();
+                    worksheet.merge_cells = old_data.merge_cells.clone();
                     worksheet.shared_formulas = old_data.shared_formulas.clone();
                     self.model.reset_parsed_structures();
 
@@ -2213,33 +2322,20 @@ impl UserModel {
                         self.model.delete_row_style(*sheet, *row)?;
                     }
                 }
-                Diff::MergeCells {
+                Diff::MoveColumn {
                     sheet,
-                    row,
                     column,
-                    width,
-                    height,
-                    old_data,
+                    delta,
                 } => {
-                    needs_evaluation = true;
-                    self.model.unmerge_cells(*sheet, *row, *column)?;
-                    // for (r, c, v) in old_data.iter() {
-                    //     self.model
-                    //         .workbook
-                    //         .worksheet_mut(*sheet)?
-                    //         .update_cell(*r, *c, v.clone())?;
-                    // }
-                }
-                Diff::UnmergeCells {
-                    sheet,
-                    row,
-                    column,
-                    width,
-                    height,
-                } => {
-                    needs_evaluation = true;
+                    // For undo, we apply the opposite move
                     self.model
-                        .merge_cells(*sheet, *row, *column, *width, *height)?;
+                        .move_column_action(*sheet, *column + *delta, -*delta)?;
+                    needs_evaluation = true;
+                }
+                Diff::MoveRow { sheet, row, delta } => {
+                    // For undo, we apply the opposite move
+                    self.model.move_row_action(*sheet, *row + *delta, -*delta)?;
+                    needs_evaluation = true;
                 }
             }
         }
@@ -2309,28 +2405,34 @@ impl UserModel {
                 } => self
                     .model
                     .set_cell_style(*sheet, *row, *column, new_value)?,
-                Diff::InsertRow { sheet, row } => {
-                    self.model.insert_rows(*sheet, *row, 1)?;
+                Diff::InsertRows { sheet, row, count } => {
+                    self.model.insert_rows(*sheet, *row, *count)?;
                     needs_evaluation = true;
                 }
-                Diff::DeleteRow {
+                Diff::DeleteRows {
                     sheet,
                     row,
+                    count,
                     old_data: _,
                 } => {
-                    self.model.delete_rows(*sheet, *row, 1)?;
+                    self.model.delete_rows(*sheet, *row, *count)?;
                     needs_evaluation = true;
                 }
-                Diff::InsertColumn { sheet, column } => {
-                    needs_evaluation = true;
-                    self.model.insert_columns(*sheet, *column, 1)?;
-                }
-                Diff::DeleteColumn {
+                Diff::InsertColumns {
                     sheet,
                     column,
+                    count,
+                } => {
+                    self.model.insert_columns(*sheet, *column, *count)?;
+                    needs_evaluation = true;
+                }
+                Diff::DeleteColumns {
+                    sheet,
+                    column,
+                    count,
                     old_data: _,
                 } => {
-                    self.model.delete_columns(*sheet, *column, 1)?;
+                    self.model.delete_columns(*sheet, *column, *count)?;
                     needs_evaluation = true;
                 }
                 Diff::SetFrozenRowsCount {
@@ -2442,33 +2544,17 @@ impl UserModel {
                 } => {
                     self.model.delete_row_style(*sheet, *row)?;
                 }
-                Diff::MergeCells {
+                Diff::MoveColumn {
                     sheet,
-                    row,
                     column,
-                    width,
-                    height,
-                    old_data: _,
+                    delta,
                 } => {
+                    self.model.move_column_action(*sheet, *column, *delta)?;
                     needs_evaluation = true;
-                    self.model
-                        .merge_cells(*sheet, *row, *column, *width, *height)?;
-                    // for (r, c, v) in old_data.iter() {
-                    //     self.model
-                    //         .workbook
-                    //         .worksheet_mut(*sheet)?
-                    //         .update_cell(*r, *c, v.clone())?;
-                    // }
                 }
-                Diff::UnmergeCells {
-                    sheet,
-                    row,
-                    column,
-                    width,
-                    height,
-                } => {
+                Diff::MoveRow { sheet, row, delta } => {
+                    self.model.move_row_action(*sheet, *row, *delta)?;
                     needs_evaluation = true;
-                    self.model.unmerge_cells(*sheet, *row, *column)?;
                 }
             }
         }
@@ -2497,7 +2583,7 @@ mod tests {
             VerticalAlignment::Top,
         ];
         for a in all {
-            assert_eq!(vertical(&format!("{}", a)), Ok(a));
+            assert_eq!(vertical(&format!("{a}")), Ok(a));
         }
     }
 
@@ -2514,7 +2600,7 @@ mod tests {
             HorizontalAlignment::Right,
         ];
         for a in all {
-            assert_eq!(horizontal(&format!("{}", a)), Ok(a));
+            assert_eq!(horizontal(&format!("{a}")), Ok(a));
         }
     }
 }

base/src/user_model/history.rs

@@ -87,23 +87,27 @@ pub(crate) enum Diff {
         row: i32,
         old_value: Box<Option<Style>>,
     },
-    InsertRow {
+    InsertRows {
         sheet: u32,
         row: i32,
+        count: i32,
     },
-    DeleteRow {
+    DeleteRows {
         sheet: u32,
         row: i32,
-        old_data: Box<RowData>,
+        count: i32,
+        old_data: Vec<RowData>,
     },
-    InsertColumn {
+    InsertColumns {
         sheet: u32,
         column: i32,
+        count: i32,
     },
-    DeleteColumn {
+    DeleteColumns {
         sheet: u32,
         column: i32,
-        old_data: Box<ColumnData>,
+        count: i32,
+        old_data: Vec<ColumnData>,
     },
     DeleteSheet {
         sheet: u32,
@@ -161,21 +165,17 @@ pub(crate) enum Diff {
         new_scope: Option<u32>,
         new_formula: String,
     },
-    MergeCells {
+    MoveColumn {
         sheet: u32,
-        row: i32,
         column: i32,
-        width: i32,
-        height: i32,
-        old_data: Vec<(Cell, Style)>,
+        delta: i32,
     },
-    UnmergeCells {
+    MoveRow {
         sheet: u32,
         row: i32,
-        column: i32,
-        width: i32,
-        height: i32,
-    }, // FIXME: we are missing SetViewDiffs
+        delta: i32,
+    },
+    // FIXME: we are missing SetViewDiffs
 }
 
 pub(crate) type DiffList = Vec<Diff>;

base/src/user_model/mod.rs

@@ -3,7 +3,7 @@
 mod border;
 mod border_utils;
 mod common;
-mod history;
+pub(crate) mod history;
 mod ui;
 
 pub use common::UserModel;

base/src/user_model/ui.rs

@@ -3,8 +3,9 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
+    constants::{LAST_COLUMN, LAST_ROW},
     expressions::utils::{is_valid_column_number, is_valid_row},
-    CellStructure,
+    worksheet::NavigationDirection,
 };
 
 use super::common::UserModel;
@@ -79,7 +80,7 @@ impl UserModel {
     /// Sets the the selected sheet
     pub fn set_selected_sheet(&mut self, sheet: u32) -> Result<(), String> {
         if self.model.workbook.worksheet(sheet).is_err() {
-            return Err(format!("Invalid worksheet index {}", sheet));
+            return Err(format!("Invalid worksheet index {sheet}"));
         }
         if let Some(view) = self.model.workbook.views.get_mut(&0) {
             view.sheet = sheet;
@@ -100,47 +101,26 @@ impl UserModel {
         if !is_valid_row(row) {
             return Err(format!("Invalid row: '{row}'"));
         }
-        let worksheet = self.model.workbook.worksheet_mut(sheet)?;
-        let structure = worksheet.get_cell_structure(row, column)?;
-        // check if the selected cell is a merged cell
-        let [row_start, columns_start, row_end, columns_end] = match structure {
-            CellStructure::Simple => [row, column, row, column],
-            CellStructure::Merged {
-                row: row_start,
-                column: column_start,
-            } => {
-                let (width, height) = match worksheet.merged_cells.get(&(row_start, column_start)) {
-                    Some(s) => s,
-                    None => return Err(format!("Merged cell not found: ({row_start}, {column_start}) when clicking at ({row}, {column}).")),
-                };
-                let row_end = row_start + height - 1;
-                let column_end = column_start + width - 1;
-                [row_start, column_start, row_end, column_end]
-            }
-            CellStructure::MergedRoot { width, height } => {
-                let row_start = row;
-                let columns_start = column;
-                let row_end = row + height - 1;
-                let columns_end = column + width - 1;
-                [row_start, columns_start, row_end, columns_end]
-            }
-        };
-        if let Some(view) = worksheet.views.get_mut(&0) {
-            view.row = row_start;
-            view.column = columns_start;
-            view.range = [row_start, columns_start, row_end, columns_end];
+        if self.model.workbook.worksheet(sheet).is_err() {
+            return Err(format!("Invalid worksheet index {sheet}"));
+        }
+        if let Ok(worksheet) = self.model.workbook.worksheet_mut(sheet) {
+            if let Some(view) = worksheet.views.get_mut(&0) {
+                view.row = row;
+                view.column = column;
+                view.range = [row, column, row, column];
+            }
         }
-
         Ok(())
     }
 
-    /// Sets the selected range. Note that the selected cell must be in one of the corners.
+    /// Sets the selected range. Note that the selected cell must be in the selected range.
     pub fn set_selected_range(
         &mut self,
-        row_start: i32,
-        column_start: i32,
-        row_end: i32,
-        column_end: i32,
+        start_row: i32,
+        start_column: i32,
+        end_row: i32,
+        end_column: i32,
     ) -> Result<(), String> {
         let sheet = if let Some(view) = self.model.workbook.views.get(&self.model.view_id) {
             view.sheet
@@ -148,72 +128,56 @@ impl UserModel {
             0
         };
 
-        if !is_valid_column_number(column_start) {
-            return Err(format!("Invalid column: '{column_start}'"));
+        if !is_valid_column_number(start_column) {
+            return Err(format!("Invalid column: '{start_column}'"));
         }
-        if !is_valid_row(row_start) {
-            return Err(format!("Invalid row: '{row_start}'"));
+        if !is_valid_row(start_row) {
+            return Err(format!("Invalid row: '{start_row}'"));
         }
 
-        if !is_valid_column_number(column_end) {
-            return Err(format!("Invalid column: '{column_end}'"));
+        if !is_valid_column_number(end_column) {
+            return Err(format!("Invalid column: '{end_column}'"));
         }
-        if !is_valid_row(row_end) {
-            return Err(format!("Invalid row: '{row_end}'"));
+        if !is_valid_row(end_row) {
+            return Err(format!("Invalid row: '{end_row}'"));
         }
-        let mut start_row = row_start;
-        let mut start_column = column_start;
-        let mut end_row = row_end;
-        let mut end_column = column_end;
-        let worksheet = self.model.workbook.worksheet_mut(sheet)?;
-        let merged_cells = &worksheet.merged_cells;
-        if !merged_cells.is_empty() {
-            // We need to check if there are merged cells in the selected range
-            for row in row_start..=row_end {
-                for column in column_start..=column_end {
-                    let structure = &worksheet.get_cell_structure(row, column)?;
-                    match structure {
-                        CellStructure::Simple => {}
-                        CellStructure::Merged { row: r, column: c } => {
-                            // The selected range must contain the merged cell
-                            let (width, height) = match merged_cells.get(&(*r, *c)) {
-                                Some(s) => s,
-                                None => return Err(format!("Merged cell not found: ({r}, {c}) when selecting range ({start_row}, {start_column}, {end_row}, {end_column}).")),
-                            };
-                            start_row = start_row.min(*r);
-                            start_column = start_column.min(*c);
-                            end_row = end_row.max(*r + height - 1);
-                            end_column = end_column.max(*c + width - 1);
-
-                        }
-                        CellStructure::MergedRoot { width, height } => {
-                            // The selected range must contain the merged cell
-                            end_row = end_row.max(row + height - 1);
-                            end_column = end_column.max(column + width - 1);
-                        }
+        if self.model.workbook.worksheet(sheet).is_err() {
+            return Err(format!("Invalid worksheet index {sheet}"));
+        }
+        if let Ok(worksheet) = self.model.workbook.worksheet_mut(sheet) {
+            if let Some(view) = worksheet.views.get_mut(&0) {
+                let selected_row = view.row;
+                let selected_column = view.column;
+                if start_row == 1 && end_row == LAST_ROW {
+                    // full row selected. The cell must be at the top or the bottom of the range
+                    if selected_column != start_column && selected_column != end_column {
+                        return Err(format!(
+                            "The selected cell is not the column edge. Column '{selected_column}' and column range '({start_column}, {end_column})'"
+                        ));
+                    }
+                } else if start_column == 1 && end_column == LAST_COLUMN {
+                    // full column selected. The cell must be at the left or the right of the range
+                    if selected_row != start_row && selected_row != end_row {
+                        return Err(format!(
+                            "The selected cell is not in the row edge. Row: '{selected_row}' and row range '({start_row}, {end_row})'"
+                        ));
+                    }
+                } else {
+                    // The selected cell must be on one of the corners of the selected range:
+                    if selected_row != start_row && selected_row != end_row {
+                        return Err(format!(
+                        "The selected cell is not in one of the corners. Row: '{selected_row}' and row range '({start_row}, {end_row})'"
+                    ));
+                    }
+                    if selected_column != start_column && selected_column != end_column {
+                        return Err(format!(
+                        "The selected cell is not in one of the corners. Column '{selected_column}' and column range '({start_column}, {end_column})'"
+                    ));
                     }
                 }
+                view.range = [start_row, start_column, end_row, end_column];
             }
         }
-        if let Some(view) = worksheet.views.get_mut(&0) {
-            // let selected_row = view.row;
-            // let selected_column = view.column;
-            // // The selected cells must be on one of the corners of the selected range:
-            // if selected_row != start_row && selected_row != end_row {
-            //     return Err(format!(
-            //             "The selected cells is not in one of the corners. Row: '{}' and row range '({}, {})'",
-            //             selected_row, start_row, end_row
-            //         ));
-            // }
-            // if selected_column != start_column && selected_column != end_column {
-            //     return Err(format!(
-            //             "The selected cells is not in one of the corners. Column '{}' and column range '({}, {})'",
-            //             selected_column, start_column, end_column
-            //         ));
-            // }
-            view.range = [start_row, start_column, end_row, end_column];
-        }
-
         Ok(())
     }
 
@@ -246,6 +210,17 @@ impl UserModel {
                 return Ok(());
             };
         let [row_start, column_start, row_end, column_end] = range;
+        if ["ArrowUp", "ArrowDown"].contains(&key) && row_start == 1 && row_end == LAST_ROW {
+            // full column selected, nothing to do
+            return Ok(());
+        }
+        if ["ArrowRight", "ArrowLeft"].contains(&key)
+            && column_start == 1
+            && column_end == LAST_COLUMN
+        {
+            // full row selected, nothing to do
+            return Ok(());
+        }
 
         match key {
             "ArrowRight" => {
@@ -361,7 +336,7 @@ impl UserModel {
             return Err(format!("Invalid row: '{top_row}'"));
         }
         if self.model.workbook.worksheet(sheet).is_err() {
-            return Err(format!("Invalid worksheet index {}", sheet));
+            return Err(format!("Invalid worksheet index {sheet}"));
         }
         if let Ok(worksheet) = self.model.workbook.worksheet_mut(sheet) {
             if let Some(view) = worksheet.views.get_mut(&0) {
@@ -528,7 +503,7 @@ impl UserModel {
         // if the row is not fully visible we 'scroll' down until it is
         let mut height = 0.0;
         let mut row = view.top_row;
-        while row <= new_row + 1 {
+        while row <= new_row + 1 && row <= LAST_ROW {
             height += self.model.get_row_height(sheet, row)?;
             row += 1;
         }
@@ -738,4 +713,94 @@ impl UserModel {
 
         Ok(())
     }
+
+    /// User navigates to the edge in the given direction
+    pub fn on_navigate_to_edge_in_direction(
+        &mut self,
+        direction: NavigationDirection,
+    ) -> Result<(), String> {
+        let (sheet, window_height, window_width) =
+            if let Some(view) = self.model.workbook.views.get(&self.model.view_id) {
+                (view.sheet, view.window_height, view.window_width)
+            } else {
+                return Err("View not found".to_string());
+            };
+        let worksheet = match self.model.workbook.worksheet(sheet) {
+            Ok(s) => s,
+            Err(_) => return Err("Worksheet not found".to_string()),
+        };
+        let view = match worksheet.views.get(&self.model.view_id) {
+            Some(s) => s,
+            None => return Err("View not found".to_string()),
+        };
+        let row = view.row;
+        let column = view.column;
+        if !is_valid_row(row) || !is_valid_column_number(column) {
+            return Err("Invalid row or column".to_string());
+        }
+        let (new_row, new_column) =
+            worksheet.navigate_to_edge_in_direction(row, column, direction)?;
+        if !is_valid_row(new_row) || !is_valid_column_number(new_column) {
+            return Err("Invalid row or column after navigation".to_string());
+        }
+        if new_row == row && new_column == column {
+            return Ok(()); // No change in selection
+        }
+
+        let mut top_row = view.top_row;
+        let mut left_column = view.left_column;
+
+        match direction {
+            NavigationDirection::Left | NavigationDirection::Right => {
+                // If the new column is not fully visible we 'scroll' until it is
+                // We need to check two conditions:
+                // 1. new_column > view.left_column
+                // 2. right_column < new_column
+                if new_column < view.left_column {
+                    left_column = new_column;
+                } else {
+                    let mut c = new_column;
+                    let mut width = self.model.get_column_width(sheet, c)?;
+                    while c > 1 && width <= window_width as f64 {
+                        c -= 1;
+                        width += self.model.get_column_width(sheet, c)?;
+                    }
+                    if c > view.left_column {
+                        left_column = c;
+                    }
+                }
+            }
+            NavigationDirection::Up | NavigationDirection::Down => {
+                // If the new row is not fully visible we 'scroll' until it is
+                // We need to check two conditions:
+                // 1. new_row > view.top_row
+                // 2. bottom_row < new_row
+                if new_row < view.top_row {
+                    top_row = new_row;
+                } else {
+                    let mut r = new_row;
+                    let mut height = self.model.get_row_height(sheet, r)?;
+                    while r > 1 && height <= window_height as f64 {
+                        r -= 1;
+                        height += self.model.get_row_height(sheet, r)?;
+                    }
+                    if r > view.top_row {
+                        top_row = r;
+                    }
+                }
+            }
+        }
+
+        if let Ok(worksheet) = self.model.workbook.worksheet_mut(sheet) {
+            if let Some(view) = worksheet.views.get_mut(&self.model.view_id) {
+                view.row = new_row;
+                view.column = new_column;
+                view.range = [new_row, new_column, new_row, new_column];
+
+                view.top_row = top_row;
+                view.left_column = left_column;
+            }
+        }
+        Ok(())
+    }
 }

base/src/worksheet.rs

@@ -1,7 +1,6 @@
 use crate::constants::{self, LAST_COLUMN, LAST_ROW};
 use crate::expressions::types::CellReferenceIndex;
 use crate::expressions::utils::{is_valid_column_number, is_valid_row};
-use crate::CellStructure;
 use crate::{expressions::token::Error, types::*};
 
 use std::collections::HashMap;
@@ -39,24 +38,6 @@ impl Worksheet {
         self.sheet_data.get(&row)?.get(&column)
     }
 
-    pub fn get_cell_structure(&self, row: i32, column: i32) -> Result<CellStructure, String> {
-        if let Some((width, height)) = self.merged_cells.get(&(row, column)) {
-            return Ok(CellStructure::MergedRoot {
-                width: *width,
-                height: *height,
-            });
-        }
-        let cell = self.cell(row, column);
-        if let Some(Cell::Merged { r, c }) = cell {
-            return Ok(CellStructure::Merged {
-                row: *r,
-                column: *c,
-            });
-        }
-
-        Ok(CellStructure::Simple)
-    }
-
     pub(crate) fn cell_mut(&mut self, row: i32, column: i32) -> Option<&mut Cell> {
         self.sheet_data.get_mut(&row)?.get_mut(&column)
     }

bindings/nodejs/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 edition = "2021"
 name = "ironcalc_nodejs"
-version = "0.5.0"
+version = "0.6.0"
 
 [lib]
 crate-type = ["cdylib"]
@@ -10,7 +10,7 @@ crate-type = ["cdylib"]
 # Default enable napi4 feature, see https://nodejs.org/api/n-api.html#node-api-version-matrix
 napi = { version = "2.12.2", default-features = false, features = ["napi4", "serde-json"] }
 napi-derive = "2.12.2"
-ironcalc = { path = "../../xlsx", version = "0.5.0" }
+ironcalc = { path = "../../xlsx", version = "0.6.0" }
 serde = { version = "1.0", features = ["derive"] }
 
 [build-dependencies]

bindings/nodejs/README.md

@@ -4,15 +4,20 @@
 Example usage:
 
 ```javascript
-import { Model } from '@ironcalc/wasm';
+import { Model } from '@ironcalc/nodejs';
  
 const model = new Model("Workbook1", "en", "UTC");
 
 model.setUserInput(0, 1, 1, "=1+1");
-const result1 = model.getFormattedCellValue(0, 1, 1);
 
-console.log('Cell value', result1);
+const result1 = model.getFormattedCellValue(0, 1, 1);
+console.log('Cell value', result1); // "#ERROR"
+
+model.evaluate();
+
+const resultAfterEvaluate = model.getFormattedCellValue(0, 1, 1);
+console.log('Cell value', resultAfterEvaluate); // 2
 
 let result2 = model.getCellStyle(0, 1, 1);
 console.log('Cell style', result2);
-```
+```

bindings/nodejs/index.d.ts

@@ -59,10 +59,10 @@ export declare class UserModel {
   setSheetColor(sheet: number, color: string): void
   rangeClearAll(sheet: number, startRow: number, startColumn: number, endRow: number, endColumn: number): void
   rangeClearContents(sheet: number, startRow: number, startColumn: number, endRow: number, endColumn: number): void
-  insertRow(sheet: number, row: number): void
-  insertColumn(sheet: number, column: number): void
-  deleteRow(sheet: number, row: number): void
-  deleteColumn(sheet: number, column: number): void
+  insertRows(sheet: number, row: number, rowCount: number): void
+  insertColumns(sheet: number, column: number, columnCount: number): void
+  deleteRows(sheet: number, row: number, rowCount: number): void
+  deleteColumns(sheet: number, column: number, columnCount: number): void
   setRowHeight(sheet: number, row: number, height: number): void
   setColumnWidth(sheet: number, column: number, width: number): void
   getRowHeight(sheet: number, row: number): number

bindings/nodejs/src/model.rs

@@ -340,4 +340,20 @@ impl Model {
       .delete_defined_name(&name, scope)
       .map_err(|e| to_js_error(e.to_string()))
   }
+
+  #[napi(js_name = "moveColumn")]
+  pub fn move_column(&mut self, sheet: u32, column: i32, delta: i32) -> Result<()> {
+    self
+      .model
+      .move_column_action(sheet, column, delta)
+      .map_err(to_js_error)
+  }
+
+  #[napi(js_name = "moveRow")]
+  pub fn move_row(&mut self, sheet: u32, row: i32, delta: i32) -> Result<()> {
+    self
+      .model
+      .move_row_action(sheet, row, delta)
+      .map_err(to_js_error)
+  }
 }

bindings/nodejs/src/user_model.rs

@@ -183,24 +183,36 @@ impl UserModel {
       .map_err(to_js_error)
   }
 
-  #[napi(js_name = "insertRow")]
-  pub fn insert_row(&mut self, sheet: u32, row: i32) -> Result<()> {
-    self.model.insert_row(sheet, row).map_err(to_js_error)
+  #[napi(js_name = "insertRows")]
+  pub fn insert_rows(&mut self, sheet: u32, row: i32, row_count: i32) -> Result<()> {
+    self
+      .model
+      .insert_rows(sheet, row, row_count)
+      .map_err(to_js_error)
   }
 
-  #[napi(js_name = "insertColumn")]
-  pub fn insert_column(&mut self, sheet: u32, column: i32) -> Result<()> {
-    self.model.insert_column(sheet, column).map_err(to_js_error)
+  #[napi(js_name = "insertColumns")]
+  pub fn insert_columns(&mut self, sheet: u32, column: i32, column_count: i32) -> Result<()> {
+    self
+      .model
+      .insert_columns(sheet, column, column_count)
+      .map_err(to_js_error)
   }
 
-  #[napi(js_name = "deleteRow")]
-  pub fn delete_row(&mut self, sheet: u32, row: i32) -> Result<()> {
-    self.model.delete_row(sheet, row).map_err(to_js_error)
+  #[napi(js_name = "deleteRows")]
+  pub fn delete_rows(&mut self, sheet: u32, row: i32, row_count: i32) -> Result<()> {
+    self
+      .model
+      .delete_rows(sheet, row, row_count)
+      .map_err(to_js_error)
   }
 
-  #[napi(js_name = "deleteColumn")]
-  pub fn delete_column(&mut self, sheet: u32, column: i32) -> Result<()> {
-    self.model.delete_column(sheet, column).map_err(to_js_error)
+  #[napi(js_name = "deleteColumns")]
+  pub fn delete_columns(&mut self, sheet: u32, column: i32, column_count: i32) -> Result<()> {
+    self
+      .model
+      .delete_columns(sheet, column, column_count)
+      .map_err(to_js_error)
   }
 
   #[napi(js_name = "setRowsHeight")]
@@ -651,4 +663,20 @@ impl UserModel {
       .delete_defined_name(&name, scope)
       .map_err(|e| to_js_error(e.to_string()))
   }
+
+  #[napi(js_name = "moveColumn")]
+  pub fn move_column(&mut self, sheet: u32, column: i32, delta: i32) -> Result<()> {
+    self
+      .model
+      .move_column_action(sheet, column, delta)
+      .map_err(to_js_error)
+  }
+
+  #[napi(js_name = "moveRow")]
+  pub fn move_row(&mut self, sheet: u32, row: i32, delta: i32) -> Result<()> {
+    self
+      .model
+      .move_row_action(sheet, row, delta)
+      .map_err(to_js_error)
+  }
 }

bindings/python/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pyroncalc"
-version = "0.5.0"
+version = "0.6.0"
 edition = "2021"
 
 
@@ -12,8 +12,9 @@ crate-type = ["cdylib"]
 [dependencies]
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-xlsx = { package= "ironcalc", path = "../../xlsx", version = "0.5.0" }
-pyo3 = { version = "0.23", features = ["extension-module"] }
+xlsx = { package= "ironcalc", path = "../../xlsx", version = "0.6.0" }
+pyo3 = { version = "0.25", features = ["extension-module"] }
+bitcode = "0.6.3"
 
 
 [features]