WIP

base/CALC.md

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+# 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