This package defines a comonadic zipper for non-empty (finite) sequences, backed by Data.Sequence from the containers package.
Where a more familiar cons-list-backed non-empty comonadic list zipper principally allows for
- Comonadic function application and composition.
- Efficient linear traversal.
- Efficient modification at or next to the focus value.
...a Seq-backed zipper also allows for
- Efficient access to the outside edges of sequence.
- Efficient random access to arbitrary locations in the prefix or suffix of the zipper.
- Efficient movement of the cursor (focus) to arbitrary indices.
See the top-level documentation of Data.Sequence.NonEmpty/Zipper for more information.