A simple programming language vaguely inspired the ML family of languages.
This is a work in progress! Made for fun to better understand type systems.

Resources used:

• Type Inference and Unification, CS3110 Cornell
• Algorithm W Step by Step, Martin Grabmuller
• Write You a Haskell, Stephen Diehl
• Type and Programming Languages, Benjamin C. Pierce

> let x = 10;
> :type x
x : Int
> let id x = x;
> :type ident
id : ∀a. a -> a
> id x
10 : Int
> id True
True
> let inc = fn x -> x + 1
> inc 1
2 : Int
> letrec fac n = if n == 0 then 1 else n * (fac (n - 1));
> fac 7
5040

• Load source from file
• Make an executable to interpret/typecheck/repl
• Basic IO
• Better error messages
• More built in data types (List, Char, String, Float, Tuple)
• Custom data types and type synonyms (records?)
• Polymorphic operators (+, -, ==...)
• Provide type signatures

Maybe someday:

• Compiler
• Pattern matching
• Module system