An implementation of the Nominal Wyvern type system written in Haskell

(wyvernlang.github.io)

Installation uses cabal. Please run

cabal configure
cabal build

Then you should be able to run

cabal run nominal-wyvern [file]

Please see the examples/ folder for some example programs.

• Check that nested type declarations work
• Check for valid shape usage (probably at the same time, throw errors as needed)
• Allow general exprs in function calls (desugar when binding)
• Make type annotations more lenient (we can infer type of new exprs, for instance)
• Look into the extra edges rules
• Later: REPL for typing/subtyping queries