pub fn parse_range_ref(
range_str: &str,
) -> Result<(Option<String>, usize, usize, usize, usize), String>Expand description
Parse a range reference string (e.g.“A1:C10”, “Sheet1!A1:B5”, or “A1”) Returns (optional_sheet_name, start_row, start_col, end_row, end_col)