seq-zipper

This package defines a comonadic zipper for non-empty (finite) sequences, backed by Data.Sequence from the containers package.

Comparison to similar Zipper types

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.