Hi, you're in luck then, as the basic ABI is identical that of C (gcc), since g77 shares the same backend. Here's the simple example I tested it with: foo$ cat square.f SUBROUTINE SQUARE(N,M) C COMPUTES THE SQUARE OF N, RETURNS IN M M=N*N RETURN END C foo$ cat main.hs module Main where import Ptr import Storable import MarshalUtils import MarshalAlloc foreign import "square_" unsafe square_ :: Ptr Int -> Ptr Int -> IO Int square :: Int -> IO Int square x = withObject x $ \ ptr_x -> alloca $ \ ptr_res -> do square_ ptr_x ptr_res peek ptr_res main = square 11 >>= print {- --------------------- -} foo$ g77 -c square.f foo$ ghc -o main main.hs square.o -fglasgow-exts -package lang To get the name mangling and the details of passing arguments to the Fortran subroutine right, I looked at the output of "f2c -P", which gives back C prototypes for Fortran function/subs. You could certainly imagine a tool that would automate all this.. hth --sigbjorn ----- Original Message ----- From: "Heron" <heron_carvalho@bol.com.br> To: "Sigbjorn Finne" <sof@galois.com> Sent: Sunday, December 02, 2001 02:43 Subject: Re: FORTRAN and HASKELL

Thank you for your comments. Answering your question ...

...

you don't say what platform this is on (or what Fortran compiler you're using).

We are using GNU Fortran 77 Compiler (f77) on a Linux PC cluster based on Red Hat 6.2. The GHC version used is 5.02.

Best Regards, Heron de Carvalho