GF/src is now for 2.9, and the new sources are in src-3.0 - keep it this way until the release of GF 3

src-3.0/GF/Parsing/MCFG/Incremental2.hs

@@ -0,0 +1,157 @@
+----------------------------------------------------------------------
+-- |
+-- Maintainer  : PL
+-- Stability   : (stable)
+-- Portability : (portable)
+--
+-- > CVS $Date: 2005/08/08 09:01:25 $
+-- > CVS $Author: peb $
+-- > CVS $Revision: 1.3 $
+--
+-- MCFG parsing, the incremental algorithm (alternative version)
+-----------------------------------------------------------------------------
+
+module GF.Parsing.MCFG.Incremental2 (parse) where
+
+import Data.List
+import Data.Array
+import Control.Monad (guard) 
+
+import GF.Data.Utilities (select)
+import GF.Data.Assoc 
+import GF.Data.IncrementalDeduction
+
+import GF.Formalism.GCFG
+import GF.Formalism.MCFG
+import GF.Formalism.Utilities
+
+import GF.Parsing.MCFG.Range
+import GF.Parsing.MCFG.PInfo
+
+import GF.System.Tracing
+import GF.Infra.Print
+
+----------------------------------------------------------------------
+-- parsing
+
+-- parseR :: (Ord n, Ord c, Ord l, Ord t) => MCFParser c n l t
+parse pinfo starts inp =
+    accumAssoc groupSyntaxNodes $
+      [ ((cat, found), SNode fun (zip rhs rrecs)) |
+        k <- uncurry enumFromTo (inputBounds inp),
+        Final (Abs cat rhs fun) found rrecs <- chartLookup chart k Fin ]
+    where chart = process pinfo inp 
+
+--process :: (Ord n, Ord c, Ord l) => MCFPInfo c n l Range -> (Int, Int) -> IChart c n l
+process pinfo inp
+    = tracePrt "MCFG.Incremental - chart size" 
+          (prt . map (prtSizes finalChart . fst) . assocs) $ 
+      finalChart
+    where finalChart    = buildChart keyof rules axioms inBounds
+	  axioms k      = tracePrt ("MCFG.Incremental - axioms for " ++ show k) (prt . length) $
+			  predict k ++ scan k ++ complete1 k 
+	  rules  k item = complete2 k item ++ combine k item ++ convert k item
+	  inBounds      = inputBounds inp
+
+          -- axioms: predict + scan + complete
+	  predict k = do Rule abs@(Abs _ rhs _) (Cnc _ _ lins) <- rulesMatchingInput pinfo inp
+			 let daughters = replicate (length rhs) []
+			 (lin, lins') <- select lins
+			 return $ Active abs [] k lin lins' daughters 
+
+	  scan k = do (tok, js) <- aAssocs (inputTo inp ! k)
+		      j <- js
+		      Active abs found i (Lin l (Tok _tok:syms)) lins recs <- 
+			  chartLookup finalChart j (ActTok tok)
+		      return $ Active abs found i  (Lin l syms) lins recs 
+
+	  complete1 k = do j <- [fst inBounds .. k-1]
+			   Active abs found i (Lin l _Nil) lins recs <- 
+			       chartLookup finalChart j Pass
+			   let found' = found ++ [(l, makeRange (i,j))]
+			   (lin, lins') <- select lins
+			   return $ Active abs found' k lin lins' recs 
+
+          -- rules: convert + combine + complete
+	  convert k (Active rule found j (Lin lbl []) [] recs) = 
+	      let found' = found ++ [(lbl, makeRange (j,k))]
+	       in return $ Final rule found' recs
+	  convert _ _ = []
+
+	  combine k (Active (Abs cat _ _) found' j (Lin lbl []) _ _) = 
+	      do guard (j < k) ---- cannot handle epsilon-rules
+		 Active abs found i (Lin l (Cat (_cat,_lbl,nr):syms)) lins recs <- 
+		     chartLookup finalChart j (Act cat lbl)
+		 let found'' = found' ++ [(lbl, makeRange (j,k))]
+		 recs' <- unifyRec recs nr found''
+		 return $ Active abs found i (Lin l syms) lins recs'
+	  combine _ _ = []
+
+	  complete2 k (Active abs found i (Lin l []) lins recs) =
+	      do let found' = found ++ [(l, makeRange (i,k))]
+		 (lin, lins') <- select lins
+		 return $ Active abs found' k lin lins' recs 
+	  complete2 _ _ = []
+
+----------------------------------------------------------------------
+-- type definitions
+
+type IChart c n l t = IncrementalChart (Item c n l t) (IKey c l t) 
+
+data Item   c n l t = Active (Abstract c n) 
+                             (RangeRec l) 
+			     Int 
+			     (Lin c l t) 
+			     (LinRec c l t) 
+			     [RangeRec l]
+		    | Final (Abstract c n) (RangeRec l) [RangeRec l]
+		    ---- | Passive c (RangeRec l) 
+		      deriving (Eq, Ord, Show)
+
+data IKey     c l t = Act c l 
+		    | ActTok t
+		    ---- | Useless
+		    | Pass
+		    | Fin
+		      deriving (Eq, Ord, Show)
+
+keyof :: Item c n l t -> IKey c l t
+keyof (Active _ _ _ (Lin _ (Cat (next,lbl,_):_)) _ _) = Act next lbl 
+keyof (Active _ _ _ (Lin _ (Tok tok:_)) _ _) = ActTok tok 
+keyof (Active _ _ _ (Lin _ []) _ _) = Pass
+keyof (Final _ _ _) = Fin
+-- keyof _ = Useless
+
+
+----------------------------------------------------------------------
+-- for tracing purposes
+prtSizes chart k = "f=" ++ show (length (chartLookup chart k Fin)) ++
+		   " p=" ++ show (length (chartLookup chart k Pass)) ++ 
+		   " a=" ++ show (sum [length (chartLookup chart k key) | 
+					     key@(Act _ _) <- chartKeys chart k ]) ++
+		   " t=" ++ show (sum [length (chartLookup chart k key) | 
+						 key@(ActTok _) <- chartKeys chart k ]) 
+		   -- " u=" ++ show (length (chartLookup chart k Useless)) 
+
+-- prtChart chart = concat [ "\n*** KEY: " ++ prt k ++ 
+-- 			  prtBefore "\n  " (chartLookup chart k) | 
+-- 			  k <- chartKeys chart ] 
+
+instance (Print c, Print n, Print l, Print t) => Print (Item c n l t) where
+    prt (Active abs found rng lin tofind children) = 
+	"? " ++ prt abs ++ ";\n\t" ++ 
+	"{" ++ prtSep " " found ++ "} " ++ prt rng ++ " . " ++ 
+	prt lin ++ "{" ++ prtSep " " tofind ++ "}" ++
+        ( if null children then ";" else ";\n\t" ++
+	  "{" ++ prtSep "} {" (map (prtSep " ") children) ++ "}" )
+    -- prt (Passive c rrec) = "- " ++ prt c ++ "; {" ++ prtSep " " rrec ++ "}"
+    prt (Final abs rr rrs) = ": " ++ prt abs ++ ";\n\t{" ++ prtSep " " rr ++ "}" ++ 
+			     ( if null rrs then ";" else ";\n\t" ++ 
+			       "{" ++ prtSep "} {" (map (prtSep " ") rrs) ++ "}" )
+
+instance (Print c, Print l, Print t) => Print (IKey c l t) where
+    prt (Act c l) = "Active " ++ prt c ++ " " ++ prt l
+    prt (ActTok t) = "ActiveTok " ++ prt t
+    -- prt (Pass c l i) = "Passive " ++ prt c ++ " " ++ prt l ++ " @ " ++ prt i
+    prt (Fin) = "Final"
+    -- prt (Useless) = "Useless"