UPDATE: Dump of initial files

base/src/implicit_intersection.rs

@@ -0,0 +1,48 @@
+use crate::calc_result::{CellReference, Range};
+
+/// It returns the closest cell from cell_reference to range in the same column/row
+/// Examples
+///  * i_i(B5, A2:A9) -> B5
+///  * i_i(B5, A7:A9) -> None
+///  * i_i(B5, A2:D2) -> B2
+pub(crate) fn implicit_intersection(
+    cell_reference: &CellReference,
+    range: &Range,
+) -> Option<CellReference> {
+    let left = &range.left;
+    let right = &range.right;
+    let sheet = cell_reference.sheet;
+    // If they are not all in the same sheet there is no intersection
+    if sheet != left.sheet && sheet != right.sheet {
+        return None;
+    }
+    let row = cell_reference.row;
+    let column = cell_reference.column;
+    if row >= left.row && row <= right.row {
+        if left.column != right.column {
+            return None;
+        }
+        return Some(CellReference {
+            sheet,
+            row,
+            column: left.column,
+        });
+    } else if column >= left.column && column <= right.column {
+        if left.row != right.row {
+            return None;
+        }
+        return Some(CellReference {
+            sheet,
+            row: left.row,
+            column,
+        });
+    } else if left.row == right.row && left.column == right.column {
+        // If the range is a single cell, then return it.
+        return Some(CellReference {
+            sheet,
+            row: left.row,
+            column: right.column,
+        });
+    }
+    None
+}