/// Returns the [`EndIdx`] of the end at a given position, if it exists.  Used for detecting
/// 0-length end chunks.
Returns the [`EndIdx`] of the end at a given position, if it exists.  Used for detecting
0-length end chunks.
Returns the [ ` EndIdx ` ] of the end at a given position if it exists . Used for detecting 0 - length end chunks .
fn idx_of_end(&self, ch: &Row, row_idx: RowIdx) -> Option<EndIdx> {
        self.ends
            .iter_enumerated()
            .find(|(_idx, end)| end.row_idx == row_idx && &end.course_head == ch)
            .map(|(idx, _end)| idx)
    }
fn idx_of_end ( & self , ch : & Row , row_idx : RowIdx ) -> Option < EndIdx > { self . ends . iter_enumerated ( ) . find ( | ( _idx , end ) | end . row_idx == row_idx && & end . course_head == ch ) . map ( | ( idx , _end ) | idx ) }
Returns the [`EndIdx`] of the end at a given position, if it exists.
Returns the [ ` EndIdx ` ] of the end at a given position if it exists .
&self
ch
&Row
row_idx
RowIdx