foreign-ocaml

Haskell Foreign Function Interface (FFI) for OCaml. Allows integrating OCaml code into Haskell programs: right now the interface is still pretty rough, and there are probably terrible memory holes that we need to deal with, consider it as a proof of concept.

It offers:

• calling OCaml functions from Haskell;
• serialization and deserialization of OCaml datatypes, including unit, bool, int, double, string, lists, tuples and options;
• limited automatic suppport for serializing algebraic data types, works when there are no type variables (helper functions are provided for converting between the two representations, so custom serializations can be built)
• strict and lazy evaluation, support for side effects

Current limitations:

• does not support passing higher order functions to OCaml (Haskell function serialization is not supported)
• does not support OCaml objects and classes
• tuple serialization limited to tuples of 2 to 5 arguments
• no handling of garbage collection, so your program might explode

Installation

To install the OCaml-FFI module simply run:

cabal install

Usage

To learn how to use this library take a look at the example folder. There are three files:

• test.ml a OCaml file exporting some functions and an algebraic data type for trees
• Main.hs a Haskell file registering and using those functions, including an implementation of serialization/deserialization for trees
• Makefile the makefile, with commented instructions on how to build your final executable