WIP

base/CALC.md

@@ -0,0 +1,61 @@
+# Evaluation Strategy
+
+
+We have a list of the spill cells:
+
+```
+// Checks if the array starting at cell will cover cells whose values
+// has been requested
+def CheckSpill(cell, array):
+    for c in cell+array:
+        support CellHasBeenRequested(c):
+        if support is not empty:
+            return support
+    return []
+
+// Fills cells with the result (an array)
+def FillCells(cell, result):
+
+
+def EvaluateNodeInContext(node, context):
+    match node:
+        case OP(left, right, op):
+            l = EvaluateNodeInContext(left, context)?
+            r = EvaluateNodeInContext(left, context)?
+            return op(l, r)
+        case FUNCTION(args, fn):
+            ...
+        case CELL(cell):
+            EvaluateCell(cell)
+        case RANGE(start, end):
+            ...
+
+
+
+def EvaluateCell(cell):
+    if IsCellEvaluating(cell):
+        return CIRC
+    MarkEvaluating(cell)
+    result = EvaluateNodeInContext(cell.formula, cell)
+    if isSpill(result):
+        CheckSpill(cell, array)?
+        FillCells(result)
+
+
+def EvaluateWorkbook():
+    spill_cells = [cell_1, ...., cell_n];
+
+
+    for cell in spill_cells:
+        result = evaluate(cell)
+```   
+
+
+
+
+
+
+
+# When updating a cell value
+
+If it was a spill cell we nee

base/src/expressions/parser/static_analysis.rs

@@ -186,6 +186,7 @@ pub fn add_implicit_intersection(node: &mut Node, add: bool) {
     };
 }
 
+#[derive(Clone)]
 pub enum StaticResult {
     Scalar,
     Array(i32, i32),

base/src/model.rs

@@ -107,8 +107,6 @@ 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 or being evaluated
-    pub(crate) cells: HashMap<(u32, i32, i32), CellState>,
     /// The locale of the model
     pub(crate) locale: Locale,
     /// The language used
@@ -117,6 +115,15 @@ pub struct Model {
     pub(crate) tz: Tz,
     /// The view id. A view consists of a selected sheet and ranges.
     pub(crate) view_id: u32,
+    /// ** Runtime ***
+    /// The list of cells with formulas that are evaluated or being evaluated
+    pub(crate) cells: HashMap<(u32, i32, i32), CellState>,
+    /// The support graph
+    pub(crate) support_graph: HashMap<(u32, i32, i32), Vec<(u32, i32, i32)>>,
+    /// If the model is in a switch state then spill cells in the indices should be switched and recalculation redone
+    pub(crate) switch_cells: Option<(i32, i32)>,
+    /// Stack of cells being evaluated
+    pub(crate) stack: Vec<(u32, i32, i32)>,
 }
 
 // FIXME: Maybe this should be the same as CellReference
@@ -1240,6 +1247,9 @@ impl Model {
             locale,
             tz,
             view_id: 0,
+            support_graph: HashMap::new(),
+            switch_cells: None,
+            stack: Vec::new(),
         };
 
         model.parse_formulas();
@@ -1418,7 +1428,8 @@ impl Model {
             Some(cell) => match cell.get_formula() {
                 None => cell.get_text(&self.workbook.shared_strings, &self.language),
                 Some(i) => {
-                    let formula = &self.parsed_formulas[sheet as usize][i as usize].0;
+                    let (formula, static_result) =
+                        &self.parsed_formulas[sheet as usize][i as usize];
                     let cell_ref = CellReferenceRC {
                         sheet: self.workbook.worksheets[sheet as usize].get_name(),
                         row: target_row,
@@ -1800,9 +1811,9 @@ impl Model {
                     self.set_cell_with_formula(sheet, row, column, formula, new_style_index)?;
                 // Update the style if needed
                 let cell = CellReferenceIndex { sheet, row, column };
-                let parsed_formula =
-                    &self.parsed_formulas[sheet as usize][formula_index as usize].0;
-                if let Some(units) = self.compute_node_units(parsed_formula, &cell) {
+                let (parsed_formula, static_result) =
+                    self.parsed_formulas[sheet as usize][formula_index as usize].clone();
+                if let Some(units) = self.compute_node_units(&parsed_formula, &cell) {
                     let new_style_index = self
                         .workbook
                         .styles
@@ -1810,6 +1821,14 @@ impl Model {
                     let style = self.workbook.styles.get_style(new_style_index)?;
                     self.set_cell_style(sheet, row, column, &style)?
                 }
+                match static_result {
+                    StaticResult::Scalar => {}
+                    StaticResult::Array(_, _)
+                    | StaticResult::Range(_, _)
+                    | StaticResult::Unknown => {
+                        self.workbook.spill_cells.push((sheet, row, column));
+                    }
+                }
             } else {
                 // The list of currencies is '$', '€' and the local currency
                 let mut currencies = vec!["$", "€"];
@@ -2123,8 +2142,29 @@ impl Model {
 
     /// Evaluates the model with a top-down recursive algorithm
     pub fn evaluate(&mut self) {
-        // clear all computation artifacts
-        self.cells.clear();
+        let mut computed = false;
+        while !computed {
+            computed = true;
+            // clear all computation artifacts
+            self.cells.clear();
+            // Evaluate all the cells that might spill
+            let spill_cells = self.workbook.spill_cells.clone();
+            for (sheet, row, column) in spill_cells {
+                self.evaluate_cell(CellReferenceIndex { sheet, row, column });
+                if self.switch_cells.is_some() {
+                    computed = false;
+                    break;
+                }
+            }
+            if let Some((index1, index2)) = self.switch_cells {
+                computed = false;
+                // switch the cells indices in the spill_cells
+                let cell1 = self.workbook.spill_cells[index1 as usize];
+                let cell2 = self.workbook.spill_cells[index2 as usize];
+                self.workbook.spill_cells[index1 as usize] = cell2;
+                self.workbook.spill_cells[index2 as usize] = cell1;
+            }
+        }
 
         let cells = self.get_all_cells();
 

base/src/new_empty.rs

@@ -407,6 +407,7 @@ impl Model {
             },
             tables: HashMap::new(),
             views,
+            spill_cells: Vec::new(),
         };
         let parsed_formulas = Vec::new();
         let worksheets = &workbook.worksheets;
@@ -429,6 +430,9 @@ impl Model {
             language,
             tz,
             view_id: 0,
+            support_graph: HashMap::new(),
+            switch_cells: None,
+            stack: Vec::new(),
         };
         model.parse_formulas();
         Ok(model)

base/src/test/test_fn_or_xor.rs

@@ -91,12 +91,12 @@ fn fn_or_xor() {
         model._set("A10", &format!("={func}(X99:Z99"));
 
         // Reference to cell with reference to empty range
-        model._set("B11", "=X99:Z99");
+        model._set("B11", "=@X99:Z99");
         model._set("A11", &format!("={func}(B11)"));
 
         // Reference to cell with non-empty range
         model._set("X12", "1");
-        model._set("B12", "=X12:Z12");
+        model._set("B12", "=@X12:Z12");
         model._set("A12", &format!("={func}(B12)"));
 
         // Reference to text cell

base/src/types.rs

@@ -51,6 +51,8 @@ pub struct Workbook {
     pub metadata: Metadata,
     pub tables: HashMap<String, Table>,
     pub views: HashMap<u32, WorkbookView>,
+    /// The list of cells that spill in the order of evaluation
+    pub spill_cells: Vec<(u32, i32, i32)>,
 }
 
 /// A defined name. The `sheet_id` is the sheet index in case the name is local