forked from GitHub/gf-core
48 lines
1.5 KiB
Haskell
48 lines
1.5 KiB
Haskell
----------------------------------------------------------------------
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-- |
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-- Maintainer : PL
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-- Stability : (stable)
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-- Portability : (portable)
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--
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-- > CVS $Date: 2005/05/09 09:28:44 $
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-- > CVS $Author: peb $
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-- > CVS $Revision: 1.3 $
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--
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-- Basic GCFG formalism (derived from Pollard 1984)
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-----------------------------------------------------------------------------
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module GF.Formalism.GCFG where
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import GF.Formalism.Utilities (SyntaxChart)
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import GF.Data.Assoc (assocMap, accumAssoc)
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import GF.Data.SortedList (nubsort, groupPairs)
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import GF.Infra.PrintClass
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----------------------------------------------------------------------
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type Grammar c n l t = [Rule c n l t]
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data Rule c n l t = Rule (Abstract c n) (Concrete l t)
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deriving (Eq, Ord, Show)
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data Abstract cat name = Abs cat [cat] name
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deriving (Eq, Ord, Show)
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data Concrete lin term = Cnc lin [lin] term
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deriving (Eq, Ord, Show)
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----------------------------------------------------------------------
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instance (Print c, Print n, Print l, Print t) => Print (Rule n c l t) where
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prt (Rule abs cnc) = prt abs ++ " := " ++ prt cnc
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prtList = prtSep "\n"
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instance (Print c, Print n) => Print (Abstract c n) where
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prt (Abs cat args name) = prt name ++ ". " ++ prt cat ++
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( if null args then ""
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else " --> " ++ prtSep " " args )
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instance (Print l, Print t) => Print (Concrete l t) where
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prt (Cnc lcat args term) = prt term
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++ " : " ++ prt lcat ++
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( if null args then ""
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else " / " ++ prtSep " " args)
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