how to target haskell to android using jhc?

Question

I want to write a Haskell function (module) of type: String -> String to call in Android. The easiest method seems to use JHC to generate C code, then use Android NDK to generate a shared library, but I could not find any documentation for JHC. Does JHC also use Cabal to build? Is JHC stable enough to use Parsec or Attoparsec library?

Answer 1

Back in 2011 I had limited success using JHC in a similar way, but targeting iOS instead of Android. Initial results were good in just getting the thing running, but we ended up discarding JHC in favor of GHC precisely because we started getting weird compile-time errors on programs that used Parsec. Bear in mind, this was in 2011 so JHC might have improved by a lot since.

If you want to give GHC a chance, I'd recommend looking at this example which uses GHC 7.8 to compile a game for Android. I haven't used it in anger yet, but I did manage to get it working on Docker, getting as far as rebuilding the game from scratch and installing it on a real Android device, so the approach definitely has merit.

UPDATE as of August 2017: Moritz Angermann has posted detailed instructions on targeting Android with a GHC cross-compiler.