Optics for Polysemy.

Optics for interfacing with Reader, State, and Writer effects in Polysemy.

Usage

Simply import Optics.Polysemy. This serves as a drop-in replacement for Optics, Optics.State, and Optics.State.Operators.

Caveats

As best I can tell, the zoom functions cannot currently be translated with complete precision. As a result, only a few zoom functions are present here, and they behave a little strangely.

• If you use zoom or zoomMaybe to go from State s to State a, the original State s will still be present in your effect stack. Writes to the zoomed part of the s will be visible from inside the State a, and vice-versa.
• zoomMany cannot be sensibly implemented this way, so I have left it out.
• Due to difficulties with higher-order effects, I have not yet found a way to implement the magnify functions.