Files
gf-core/src/GF/Conversion/MCFGtoCFG.hs
2005-04-11 12:57:45 +00:00

50 lines
1.3 KiB
Haskell

----------------------------------------------------------------------
-- |
-- Maintainer : PL
-- Stability : (stable)
-- Portability : (portable)
--
-- > CVS $Date: 2005/04/11 13:52:48 $
-- > CVS $Author: peb $
-- > CVS $Revision: 1.1 $
--
-- Converting MCFG grammars to (possibly overgenerating) CFG
-----------------------------------------------------------------------------
module GF.Conversion.MCFGtoCFG
(convertGrammar) where
import GF.System.Tracing
import GF.Infra.Print
import Monad
import GF.Formalism.Utilities
import GF.Formalism.GCFG
import GF.Formalism.MCFG
import GF.Formalism.CFG
import GF.Conversion.Types
convertGrammar :: MGrammar -> CGrammar
convertGrammar gram = tracePrt "#context-free rules" (prt.length) $
concatMap convertRule gram
convertRule :: MRule -> [CRule]
convertRule (Rule (Abs cat args name) (Cnc _ _ record))
= [ CFRule (CCat cat lbl) rhs (CName name profile) |
Lin lbl lin <- record,
let rhs = map (mapSymbol convertArg id) lin,
let profile = map (argPlaces lin) [0 .. length args-1]
]
convertArg :: (MCat, MLabel, Int) -> CCat
convertArg (cat, lbl, _) = CCat cat lbl
argPlaces :: [Symbol (cat, lbl, Int) tok] -> Int -> [Int]
argPlaces lin nr = [ place | (nr', place) <- zip linArgs [0..], nr == nr' ]
where linArgs = [ nr' | (_, _, nr') <- filterCats lin ]