diff options
Diffstat (limited to 'src-2.9/GF/Conversion/MCFGtoCFG.hs')
| -rw-r--r-- | src-2.9/GF/Conversion/MCFGtoCFG.hs | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/src-2.9/GF/Conversion/MCFGtoCFG.hs b/src-2.9/GF/Conversion/MCFGtoCFG.hs new file mode 100644 index 000000000..a58c31d37 --- /dev/null +++ b/src-2.9/GF/Conversion/MCFGtoCFG.hs @@ -0,0 +1,53 @@ +---------------------------------------------------------------------- +-- | +-- Maintainer : PL +-- Stability : (stable) +-- Portability : (portable) +-- +-- > CVS $Date: 2005/05/09 09:28:43 $ +-- > CVS $Author: peb $ +-- > CVS $Revision: 1.6 $ +-- +-- Converting MCFG grammars to (possibly overgenerating) CFG +----------------------------------------------------------------------------- + + +module GF.Conversion.MCFGtoCFG + (convertGrammar) where + +import GF.System.Tracing +import GF.Infra.Print + +import Control.Monad +import GF.Formalism.Utilities +import GF.Formalism.GCFG +import GF.Formalism.MCFG +import GF.Formalism.CFG +import GF.Conversion.Types + +---------------------------------------------------------------------- +-- * converting (possibly erasing) MCFG grammars + +convertGrammar :: EGrammar -> CGrammar +convertGrammar gram = tracePrt "MCFGtoCFG - context-free rules" (prt.length) $ + concatMap convertRule gram + +convertRule :: ERule -> [CRule] +convertRule (Rule (Abs cat args (Name fun mprofile)) (Cnc _ _ record)) + = [ CFRule (CCat cat lbl) rhs (Name fun profile) | + Lin lbl lin <- record, + let rhs = map (mapSymbol convertArg id) lin, + let cprofile = map (Unify . argPlaces lin) [0 .. length args-1], + let profile = mprofile `composeProfiles` cprofile + ] + +convertArg :: (ECat, ELabel, 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 ] + + + + |
