@hackage changeset-lens0.1.0.0

Stateful monad transformer based on monoidal actions

A general state monad transformer with separate types for the state and the possible changes. It can be defined for any monoid action. The monoid represents "changes", "updates", "edits" or "diffs" on the state.

This package exposes utilities to transport changes along optics, such as lenses or indexed structures.