[Haskell-cafe] Calling Haskell from other languages?

[Derek Elkins]

On Tue, 2008-11-11 at 17:09 +0000, Colin Paul Adams wrote:
> >>>>> "Jake" == Jake Mcarthur <jake at pikewerks.com> writes:
> 
>     Jake> Actually, that's not the whole story. I didn't realize until
>     Jake> I sent it. There does exist good documentation for this, I
>     Jake> promise.
> 
> Good. Let me know where it is when you track it down.
> 
> The link you pointed me too doesn't seem to address my question
> directly. Also, it only talks about C.
> 
> If I want to call Haskell (and I do, perhaps) from another
> garbage-collected language (Eiffel, in particular) using C as the
> mutually understood language, am I not going to run into big problems?

Read the FFI Report.  It is relatively readable and comprehensive.
http://www.cse.unsw.edu.au/~chak/haskell/ffi/

And yes, you will have to use C as an intermediary, though you may not
have to actually write any C.  You simply expose the Haskell functions
in whatever form the other language expects.  You'll almost certainly
have to write marshalling code of some sort.