leque / simple-sub.ml

simple-sub.ml

An OCaml port of Lionel Parreaux’s simple-sub type inference implementation.

usage

type-check a file

% dune exec main examples/ss.ml
val id : 'a -> 'a

val twice : ('a ∨ 'b -> 'a) -> 'b -> 'a

val object1 : {x: int; y: 'a -> 'a}

val object2 : {x: int; y: bool}

val pick_an_object : bool -> {x: int; y: bool ∨ ('a -> 'a)}

val produce : int -> {head: int; tail: 'a} as 'a

val consume : {head: int; tail: 'a} as 'a -> int

type-check interactively via repl

% dune exec main
> let f x = x x;;
val f : 'b ∧ ('b -> 'a) -> 'a

>

Limitations

• No error handling are implemented. Parse errors and type errors offer almost no useful information.