March 2019

Haskell - Foreign Function Interface

Haskell’s FFI allows easily to cooperate with other languages. Foreign functions can call Haskell code and vice versa. Simple examples can be found in my git repository [1]. For now, the provided Makefile exposes two interesting targets:

• c_from_hask - simple program with a C function called from Haskell.
• hask_from_c - simple programm with a Haskell function called from C.

The next step is to pass more complicated structures via ForeignPtr’s.

Notes

• since version 8.4 GHC guarantees that garbage collection will never occur during an unsafe call.

Ref

• [1] https://gitweb.softwarefools.com/?p=miguel/haskell.git;a=tree;f=ffi
• [2] https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/ffi-chap.html#
• [3] https://wiki.haskell.org/Foreign_Function_Interface