I have a simple fftw wrapper which c2hs builds into a .hs file, but
when i try to use it i get an error:
$ ghc -v --make -fffi Main.hs
Glasgow Haskell Compiler, Version 6.4.2, for Haskell 98, compiled by
GHC version 6.4.2
Using package config file: /usr/lib/ghc-6.4.2/package.conf
Hsc static flags: -static
*** Chasing dependencies:
Chasing modules from: Main.hs
*** Deleting temp files
Deleting:
Fftw.chs:2:0: parse error on input `import'
here is my Fftw.chs:
module Fftw (fftwNew, fftwDestroy, fftwExecute)
import C2HS
#include "fftw3.h"
data Fftw = Fftw Integer CPtrDiff CPtrDiff CPtrDiff
fftwNew::IO Integer -> Fftw
fftwNew size = do
input <- {#call unsafe fftw_malloc#} 8*size
output <- {#call unsafe fftw_malloc#} 8*size
plan <- {#call unsafe fftw_plan_r2r_1d#} size input output 0 0
return !$ Fftw size input output plan
fftwSize::Fftw -> Integer
fftwSize (Fftw size _ _ _ ) = size
fftwDestroy::Fftw -> IO ()
fftwDestroy (Fftw _ input output plan) = do
{#call unsafe fftw_free#} input
{#call unsafe fftw_free#} output
{#call unsafe fftw_destroy_plan#} plan
fftwExecute::IO Fftw [Double] -> [Double]
fftwExecute (Fftw size input output plan) inp = do
pokeArray input (take size inp)
{#call unsafe fftw_execute#} plan
return !$ peekArray size output
and my Main.hs:
module Main where
import Fftw
main :: IO ()
main = do
fft <- fftwNew 128
putStrLn $ show $ "done"
