Clarify which sequence is reference for Del and Ins
@@ -24,6 +24,9 @@ pub enum AlignmentOperation {
/// An alignment, consisting of a score, the start and end position of the alignment on
/// sequence x and sequence y, the length of sequence x,
/// and the alignment edit operations (see `alignment::pairwise` for meaning of x and y).
+///
+/// The `Del` edit operation corresponds to a gap in the sequence x, while the `Ins`
+/// edit operation corresponds to a gap in the sequence y.
#[derive(Debug)]
pub struct Alignment {
pub score: i32,
