caymon

A tool to generate Haskell monads from polynomial Cayley representations.

Try it in browser: https://pl-uwr.bitbucket.io/caymon/caymon.html

You give it a polynomial, it gives you back:

• An equational theory (in the form of a type class),
• A monad that arises from this theory in the form of a composition of algebraic datatypes,
• An isomorphic monad in the form of a "bicodensity" monad.

The theory behind caymon is described in Equational theories and monads from polynomial Cayley representations by Maciej Piróg, Piotr Polesiuk, and Filip Sieczkowski (FOSSACS 2019).

In this repository

• A Haskell program that generates .hs files + haddock docs,
• A port to JavaScript vis GHCJS
• A website that uses the above (together with a tutorial)

Be warned!

• ⚠️ CayMon is a research-level exploratory software. Reading its source code might help you understand some details, but its overall internal chaos will give you a headache. Read source code responsibly! It is because caymon is not an implementation of the algorithm described in the paper, but the paper is a result of a series of experiments that resulted in the code in this repo (and heavy QuickChecking)!

• ⚠️ Stack no longer supports GHCJS, so you won't build jscaymon with stack build. We'll need to port it to nix, but not before the release of caymon 2.0, which is coming sooner or later.

• ⚠️ The tutorial is not really fished yet.