added the concreteName function in the Haskell binding

src/runtime/haskell-bind/PGF2.hsc

@@ -51,7 +51,7 @@ module PGF2 (-- * PGF
              compute,
 
              -- * Concrete syntax
-             ConcName,Concr,languages,
+             ConcName,Concr,languages,concreteName,
              -- ** Linearization
              linearize,linearizeAll,tabularLinearize,bracketedLinearize,
              FId, LIndex, BracketedString(..), showBracketedString, flattenBracketedString,
@@ -150,6 +150,11 @@ languages p =
       concr <- fmap (\ptr -> Concr ptr (touchPGF p)) $ peek (castPtr value)
       writeIORef ref $! Map.insert name concr langs
 
+-- | The abstract language name is the name of the top-level
+-- abstract module
+concreteName :: Concr -> ConcName
+concreteName c = unsafePerformIO (peekUtf8CString =<< pgf_concrete_name (concr c))
+
 -- | Generates an exhaustive possibly infinite list of
 -- all abstract syntax expressions of the given type. 
 -- The expressions are ordered by their probability.