Thanks, Daniel. I'm still stumped. When I say #include "B.hs" in a .hs file, all works fine, but when in a .lhs file I get "error: B.hs: No such file or directory". The file B.hs is in the same directory as the including file, which is the current directory for ghci. Same situation with ghc. If I change "B.hs" to "./B.hs", I get the same behavior. Only if I use a fully qualified path name for B.hs does it get found from the .lhs file. I'm using GHC 6.12.3 on Mac OS 10.6.6. Any ideas? (Anyone, not just Daniel.) Thanks, - Conal On Thu, Feb 3, 2011 at 2:51 AM, Daniel Fischer < daniel.is.fischer@googlemail.com> wrote:
On Thursday 03 February 2011 10:33:23, Conal Elliott wrote:
Does anyone have a working example of #include'ing Haskell code into a bird-tracks-style .lhs file with GHC? Every way I try leads to parsing errors. Is there documentation about how it's supposed to work?
Help much appreciated. - Conal
Stupid example:
-- Main:
{-# LANGUAGE CPP #-} module Main (main) where
#include "MachDeps.h"
main :: IO () main = do
#if WORD_SIZE_IN_BITS == 32
putStrLn "32 bits"
#include "Stuff32"
# else
putStrLn "64 bits"
#include "Stuff64" #endif
-- Stuff32:
putStrLn "Included from Stuff32"
-- Stuff64:
putStrLn "Included from Stuff64"
It's a bit tricky. Since the C preprocessor is run after the unlit, the included code should not have bird-tracks, also you have to get the indentation right. There's probably a way to run cpp before unlit, which would allow you to have bird-tracks in the #include'd code.
Much easier with LaTeX-style literate code.
Cheers, Daniel