Work in progress on translating linearization functions to Haskell

The translation is currently good enough to translate all concrete syntaxes
of the Foods and Letter grammars, and some concrete syntaxes of the Phrasebook
grammar (e.g. PhrasebookEng & PhrasebookSpa works, but there are problems with
e.g. PhrasebookSwe and PhrasebookChi)

This functionality is enabled by running

	gf -make -output-format=haskell -haskell=concrete ...

TODO:
	- variants
	- pre { ... }
	- eta expansion of linearization functions
	- record subtyping can still cause type errors in the Haskell code
	  in some cases
	- reduce code large tables

src/compiler/GF/Compiler.hs

@@ -6,6 +6,7 @@ import PGF.Internal(putSplitAbs,encodeFile,runPut)
 import GF.Compile as S(batchCompile,link,srcAbsName)
 import GF.CompileInParallel as P(parallelBatchCompile)
 import GF.Compile.Export
+import GF.Compile.ConcreteToHaskell(concretes2haskell)
 import GF.Compile.CFGtoPGF
 import GF.Compile.GetGrammar
 import GF.Grammar.CFG
@@ -22,7 +23,7 @@ import qualified Data.Map as Map
 import qualified Data.Set as Set
 import qualified Data.ByteString.Lazy as BSL
 import System.FilePath
-import Control.Monad(unless,forM_)
+import Control.Monad(when,unless,forM_)
 
 -- | Compile the given GF grammar files. The result is a number of @.gfo@ files
 -- and, depending on the options, a @.pgf@ file. (@gf -batch@, @gf -make@)
@@ -45,6 +46,7 @@ mainGFC opts fs = do
 compileSourceFiles :: Options -> [FilePath] -> IOE ()
 compileSourceFiles opts fs = 
     do output <- batchCompile opts fs
+       cncs2haskell output
        unless (flag optStopAfterPhase opts == Compile) $
            linkGrammars opts output
   where
@@ -52,6 +54,17 @@ compileSourceFiles opts fs =
     batchCompile' opts fs = do (t,cnc_gr) <- S.batchCompile opts fs
                                return (t,[cnc_gr])
 
+    cncs2haskell output =
+      when (FmtHaskell `elem` outputFormats opts &&
+            haskellOption opts HaskellConcrete) $
+        mapM_ cnc2haskell (snd output)
+
+    cnc2haskell (cnc,gr) =
+        mapM_ writeHs $ concretes2haskell opts (srcAbsName gr cnc) gr
+
+    writeHs (path,s) = writing opts path $ writeUTF8File path s
+
+
 -- | Create a @.pgf@ file (and possibly files in other formats, if specified
 -- in the 'Options') from the output of 'parallelBatchCompile'.
 -- If a @.pgf@ file by the same name already exists and it is newer than the