"Committed_by_peb"

src/GF/Speech/TransformCFG.hs

@@ -5,22 +5,28 @@
 -- Stability   : (stable)
 -- Portability : (portable)
 --
--- > CVS $Date: 2005/04/11 13:53:39 $ 
+-- > CVS $Date: 2005/04/14 18:38:36 $ 
 -- > CVS $Author: peb $
--- > CVS $Revision: 1.9 $
+-- > CVS $Revision: 1.10 $
 --
 --  This module does some useful transformations on CFGs.
 --
 -- FIXME: remove cycles
+--
+-- peb thinks: most of this module should be moved to GF.Conversion...
 -----------------------------------------------------------------------------
 
 module TransformCFG (makeNice, CFRule_) where
 
 import Ident
-import GF.OldParsing.CFGrammar
-import GF.OldParsing.Utilities (Symbol(..))
-import GF.OldParsing.GrammarTypes
-import GF.Printing.PrintParser
+-- import GF.OldParsing.CFGrammar
+-- import GF.OldParsing.Utilities (Symbol(..))
+-- import GF.OldParsing.GrammarTypes
+-- import GF.Printing.PrintParser
+import GF.Formalism.CFG 
+import GF.Formalism.Utilities (Symbol(..), mapSymbol)
+import GF.Conversion.Types
+import GF.Infra.Print
 
 import Data.FiniteMap
 import Data.List
@@ -30,63 +36,65 @@ import Debug.Trace
 
 
 -- | not very nice to get replace the structured CFCat type with a simple string
-type CFRule_ = Rule CFName String Tokn
+type CFRule_ = CFRule Cat_ Name Token
+type Cat_ = String
 
-type CFRules = FiniteMap String [CFRule_]
+type CFRules = FiniteMap Cat_ [CFRule_]
 
-makeNice :: CFGrammar -> [CFRule_]
+makeNice :: CGrammar -> [CFRule_]
 makeNice = concat . eltsFM . makeNice' . groupProds . cfgToCFRules
     where makeNice' = removeLeftRecursion . removeEmptyCats
 
-cfgToCFRules :: CFGrammar -> [CFRule_]
-cfgToCFRules cfg = [Rule (catToString c) (map symb r) n | Rule c r n <- cfg]
-    where symb (Cat c) = Cat (catToString c)
-	  symb (Tok t) = Tok t
+cfgToCFRules :: CGrammar -> [CFRule_]
+cfgToCFRules cfg = [CFRule (catToString c) (map symb r) n | CFRule c r n <- cfg]
+    where symb = mapSymbol catToString id
+          -- symb (Cat c) = Cat (catToString c)
+	  -- symb (Tok t) = Tok t
 	  catToString = prt
 
 -- | Group productions by their lhs categories
 groupProds :: [CFRule_] -> CFRules
 groupProds = addListToFM_C (++) emptyFM . map (\rs -> (ruleCat rs,[rs]))
-    where ruleCat (Rule c _ _) = c
+    where ruleCat (CFRule c _ _) = c
 
 -- | Remove productions which use categories which have no productions
 removeEmptyCats :: CFRules -> CFRules
 removeEmptyCats rss = listToFM $ fix removeEmptyCats' $ fmToList rss
     where
-    removeEmptyCats' :: [(String,[CFRule_])] -> [(String,[CFRule_])]
+    removeEmptyCats' :: [(Cat_,[CFRule_])] -> [(Cat_,[CFRule_])]
     removeEmptyCats' rs = k'
 	where
 	keep = filter (not . null . snd) rs
-	allCats = nub [c | (_,r) <- rs, Rule _ rhs _ <- r, Cat c <- rhs]
+	allCats = nub [c | (_,r) <- rs, CFRule _ rhs _ <- r, Cat c <- rhs]
 	emptyCats = filter (nothingOrNull . flip lookup rs) allCats
 	k' = map (\ (c,xs) -> (c, filter (not . anyUsedBy emptyCats) xs)) keep
 
-anyUsedBy :: [String] -> CFRule_ -> Bool
-anyUsedBy ss (Rule _ r _) = or [c `elem` ss | Cat c <- r]
+anyUsedBy :: [Cat_] -> CFRule_ -> Bool
+anyUsedBy ss (CFRule _ r _) = or [c `elem` ss | Cat c <- r]
 
 removeLeftRecursion :: CFRules -> CFRules
 removeLeftRecursion rs = listToFM $ concatMap removeDirectLeftRecursion $ map handleProds $ fmToList rs
     where 
     handleProds (c, r) = (c, concatMap handleProd r)
-    handleProd (Rule ai (Cat aj:alpha) n) | aj < ai  =
+    handleProd (CFRule ai (Cat aj:alpha) n) | aj < ai  =
               -- FIXME: this will give multiple rules with the same name
-             [Rule ai (beta ++ alpha) n | Rule _ beta _ <- fromJust (lookupFM rs aj)]
+             [CFRule ai (beta ++ alpha) n | CFRule _ beta _ <- fromJust (lookupFM rs aj)]
     handleProd r = [r]
 
-removeDirectLeftRecursion :: (String,[CFRule_]) -- ^ All productions for a category
-			  -> [(String,[CFRule_])]
+removeDirectLeftRecursion :: (Cat_,[CFRule_]) -- ^ All productions for a category
+			  -> [(Cat_,[CFRule_])]
 removeDirectLeftRecursion (a,rs) | null dr = [(a,rs)]
 				 | otherwise = [(a, as), (a', a's)]
     where 
     a' = a ++ "'" -- FIXME: this might not be unique
     (dr,nr) = partition isDirectLeftRecursive rs
     as = maybeEndWithA' nr
-    is = [Rule a' (tail r) n | Rule _ r n <- dr]
+    is = [CFRule a' (tail r) n | CFRule _ r n <- dr]
     a's = maybeEndWithA' is
-    maybeEndWithA' xs = xs ++ [Rule c (r++[Cat a']) n | Rule c r n <- xs]
+    maybeEndWithA' xs = xs ++ [CFRule c (r++[Cat a']) n | CFRule c r n <- xs]
 
 isDirectLeftRecursive :: CFRule_ -> Bool
-isDirectLeftRecursive (Rule c (Cat c':_) _) = c == c'
+isDirectLeftRecursive (CFRule c (Cat c':_) _) = c == c'
 isDirectLeftRecursive _ = False