added startCat

src/runtime/haskell/PGF.hs

@@ -3,7 +3,7 @@ module PGF ( PGF2.PGF, readPGF
 
            , CId, mkCId, wildCId, showCId, readCId
 
-           , categories
+           , PGF2.categories, PGF2.categoryContext, PGF2.startCat
            , functions, functionsByCat
 
            , PGF2.Expr(..), PGF2.Literal(..), Tree

src/runtime/haskell/PGF2.hsc

@@ -33,7 +33,7 @@ module PGF2 (-- * PGF
              mkFloat,  unFloat,
              mkMeta,   unMeta,
              -- ** Types
-             Type(..), Hypo, BindType(..),
+             Type(..), Hypo, BindType(..), startCat,
              readType,
              mkType, unType,
              mkHypo, mkDepHypo, mkImplHypo,
@@ -139,6 +139,20 @@ abstractName p =
   bracket (pgf_abstract_name p_pgf) free $ \c_text ->
     peekText c_text
 
+-- | The start category is defined in the grammar with
+-- the \'startcat\' flag. This is usually the sentence category
+-- but it is not necessary. Despite that there is a start category
+-- defined you can parse with any category. The start category
+-- definition is just for convenience.
+startCat :: PGF -> Type
+startCat p =
+  unsafePerformIO $
+  withForeignPtr (a_pgf p) $ \c_pgf -> do
+    c_typ <- pgf_start_cat c_pgf
+    typ <- deRefStablePtr c_typ
+    freeStablePtr c_typ
+    return typ
+
 -- | The type of a function
 functionType :: PGF -> Fun -> Maybe Type
 functionType p fn =

src/runtime/haskell/PGF2/FFI.hsc

@@ -63,6 +63,9 @@ foreign import ccall "wrapper"
 foreign import ccall "pgf_iter_categories"
   pgf_iter_categories :: Ptr PgfPGF -> Ptr PgfItor -> IO ()
 
+foreign import ccall "pgf_start_cat"
+  pgf_start_cat :: Ptr PgfPGF -> IO (StablePtr Type)
+
 foreign import ccall "pgf/pgf.h pgf_category_context"
   pgf_category_context :: Ptr PgfPGF -> Ptr PgfText -> Ptr CSize -> IO (Ptr PgfTypeHypo)