Implementations of several variants of the lambda calculus in OCaml. For each
variant, an interpreter and a compiler to JavaScript are provided. Currently,
there are four variants:
- untyped: Almost pure, untyped lambda calculus, with integers, a print
  statement, and let-in added in order to give the language a semblance of
  usability. The file untyped/test/ackermann.lam contains implementations
  of several sorting algorithms in this language.
- simplytyped: Simply typed lambda calculus, with a fix operator added in order
  to enable recursion. I also added if statements and boolean variables.
- typeinference: Like the previous implementation, but without the need to make
  every type explicit. The implementation uses constraint-based typing and the
  Hindley-Milner algorithm. This variant also supports pairs, the unit type,
  sum types, algebraic data types, pattern matching, records, let-polymorphism,
  and higher-order types.
- subtyping: A fork of the typeinference variant with rudimentary support for
  subtyping on records.
I wrote these programs primarily to learn, not to provide a useful programming
language.