initial support for BNFC syntax in context-free grammars for GF. Not all features are supported yet. Based on contribution from Gleb Lobanov

src/compiler/GF/Compiler.hs

@@ -9,6 +9,7 @@ import GF.Compile.Export
 import GF.Compile.ConcreteToHaskell(concretes2haskell)
 import GF.Compile.CFGtoPGF
 import GF.Compile.GetGrammar
+import GF.Grammar.BNFC
 import GF.Grammar.CFG
 
 --import GF.Infra.Ident(showIdent)
@@ -85,12 +86,12 @@ linkGrammars opts (t_src,~cnc_grs@(~(cnc,gr):_)) =
 
 compileCFFiles :: Options -> [FilePath] -> IOE ()
 compileCFFiles opts fs = do
-  rules <- fmap concat $ mapM (getCFRules opts) fs
+  bnfc_rules <- fmap concat $ mapM (getBNFCRules opts) fs
+  let rules = bnfc2cf bnfc_rules
   startCat <- case rules of
                 (CFRule cat _ _ : _) -> return cat
                 _                    -> fail "empty CFG"
   let pgf = cf2pgf (last fs) (uniqueFuns (mkCFG startCat Set.empty rules))
---let cnc = justModuleName (last fs)
   unless (flag optStopAfterPhase opts == Compile) $
      do probs <- liftIO (maybe (return . defaultProbabilities) readProbabilitiesFromFile (flag optProbsFile opts) pgf)
         let pgf' = setProbabilities probs $ if flag optOptimizePGF opts then optimizePGF pgf else pgf