"Committed_by_peb"

src/GF/Formalism/GCFG.hs

@@ -0,0 +1,45 @@
+----------------------------------------------------------------------
+-- |
+-- Maintainer  : PL
+-- Stability   : (stable)
+-- Portability : (portable)
+--
+-- > CVS $Date: 2005/04/11 13:52:50 $ 
+-- > CVS $Author: peb $
+-- > CVS $Revision: 1.1 $
+--
+-- Basic GCFG formalism (derived from Pollard 1984)
+-----------------------------------------------------------------------------
+
+module GF.Formalism.GCFG 
+    ( Grammar, Rule(..), Abstract(..), Concrete(..)
+    ) where
+
+import GF.Infra.Print
+
+----------------------------------------------------------------------
+
+type Grammar c n l t  = [Rule c n l t]
+data Rule    c n l t  = Rule (Abstract c n) (Concrete l t)
+			deriving (Eq, Ord, Show)
+
+data Abstract cat name = Abs cat [cat] name 
+			 deriving (Eq, Ord, Show)
+data Concrete lin term = Cnc lin [lin] term 
+			 deriving (Eq, Ord, Show)
+
+----------------------------------------------------------------------
+
+instance (Print c, Print n, Print l, Print t) => Print (Rule n c l t) where
+    prt (Rule abs cnc) = prt abs ++ " := " ++ prt cnc 
+    prtList = prtSep "\n"
+
+instance (Print c, Print n) => Print (Abstract c n) where
+    prt (Abs cat args name) = prt name ++ ". " ++ prt cat ++ 
+			      ( if null args then ""
+				else " -> " ++ prtSep " " args )
+
+instance (Print l, Print t) => Print (Concrete l t) where
+    prt (Cnc lcat args term) = prt term ++ " : " ++ prt lcat ++ 
+			      ( if null args then ""
+				else " / " ++ prtSep " " args)