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----------------------------------------------------------------------
-- |
-- 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)
|
