Calling Haskell from Python / C++

[Keith Wansbrough]

> So here is what I envision: I write the main
> application in Python. I write a (hopefully) small
> Haskell module that:
> a) Calls back to the main Python app for reading the
> text to be parsed, preferably using laziness.
> b) Parses the text, and maybe processes a bit.
> c) Returns the parsed data-structure. (This may be
> tricky, but I think I know how to do it).

You might be able to get away with running the Haskell program as a separate process, communicating via pipes.  Look at Posix.popen (not available in the new libraries yet):

http://www.haskell.org/ghc/docs/latest/html/hslibs/popen.html

This is probably easier to achieve than trying to link the programs together, but it does limit you to bytestream communication both ways.

--KW 8-)
-- 
Keith Wansbrough <kw217@cl.cam.ac.uk>
http://www.cl.cam.ac.uk/users/kw217/
University of Cambridge Computer Laboratory.