Interpreter for SiFun (Simple Functional) Language with three different type systems (supports Higher-Rank Polymorphism).
Currently supports Hindley–Milner type system (simply typed lambda calculus) and Hindley–Milner with Visible Type Application (similar to System F).
Under development is a Bidirectional Typechecking System which will support Higher-Rank Polymorphism without typed function and type application.
You can clone this repository using:
git clone git@github.com:kkd26/SiFun.git
cd SiFun
opam install .or use the official opam release using:
opam install sifunThere are two ways to interact with the interpreter:
SiFun REPL (Read–eval–print loop) - interactive console
sifuniSiFun Interpreter - run from file
sifun <filename>The basic language supports (similar to Hindley–Milner type system):
1, 2, 3, ...true, falsex, y, ...(1, true)fst (1,3), snd (4,5), ...fn x => x, fn x => fn y => (x,y), ...(fn x => (1,x)) 2, ...The additional features are (similar to System F):
fn x : int => x, ...a, b, c, ...forall a. a->a, forall a b c. a->b->c, ...lam a. (int, fn x : a => x), lam a b c. fn x : a => x, ...(lam a. fn x : a => x) {int}, ...Note that ; separates blocks of code and ;; sends EOF, so stops execution.
You can check ./examples for more information about the syntax and semantics.