Question

I want to deploy an application on Windows that needs to access the GHC API. Using the first simple example from the Wiki:

http://www.haskell.org/haskellwiki/GHC/As_a_library

results in the following error (compiled on one machine with haskell platform and executed on another clean windows install):
test.exe: can’t find a package database at C:\haskell\lib\package.conf.d

I’d like to deploy my application as a simple zip file and not require the user to have anything installed. Is there a straightforward way to include the needed GHC things in that zip file so it will work?

Answer 1

This program will copy necessary files to the specified directory (will work only on windows):

import Data.List (isSuffixOf)
import System.Environment (getArgs)
import GHC.Paths (libdir)
import System.Directory
import System.FilePath 
import System.Cmd

main = do
  [to] <- getArgs
  let libdir' = to </> "lib"
  createDirectoryIfMissing True libdir'
  copy libdir libdir'
  rawSystem "xcopy"
    [ "/e", "/q"
    , dropFileName libdir </> "mingw"
    , to </> "mingw\\"]


-- | skip some files while copying
uselessFile f
  = or $ map (`isSuffixOf` f)
    [ "."
    , "_debug.a"
    , "_p.a", ".p_hi"    -- libraries built with profiling
    , ".dyn_hi", ".dll"] -- dynamic libraries


copy from to
  = getDirectoryContents from
  >>= mapM_ copy' . filter (not . uselessFile)
  where
    copy' f = do
      let (from', to') = (from </> f, to </> f)
      isDir <- doesDirectoryExist from'
      if isDir
          then createDirectory to' >> copy from' to'
          else copyFile from' to'

After running it with destination directory as argument you will have a local copy of lib and mingw (about 300 Mb total).

You can remove unused libraries from lib to save more space.