"Committed_by_peb"

1 files changed, 271 insertions, 0 deletions

diff --git a/src/GF/Formalism/Utilities.hs b/src/GF/Formalism/Utilities.hs
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+----------------------------------------------------------------------
+-- |
+-- Maintainer  : PL
+-- Stability   : (stable)
+-- Portability : (portable)
+--
+-- > CVS $Date: 2005/04/11 13:52:50 $ 
+-- > CVS $Author: peb $
+-- > CVS $Revision: 1.1 $
+--
+-- Basic type declarations and functions for grammar formalisms
+-----------------------------------------------------------------------------
+
+
+module GF.Formalism.Utilities where
+
+import Monad
+import Array
+import List (groupBy)
+
+import GF.Data.SortedList
+import GF.Data.Assoc
+import GF.Data.Utilities (sameLength, foldMerge, splitBy)
+
+import GF.Infra.Print
+
+------------------------------------------------------------
+-- * symbols
+
+data Symbol c t = Cat c | Tok t
+		  deriving (Eq, Ord, Show)
+
+symbol :: (c -> a) -> (t -> a) -> Symbol c t -> a
+symbol fc ft (Cat cat) = fc cat
+symbol fc ft (Tok tok) = ft tok
+
+mapSymbol :: (c -> d) -> (t -> u) -> Symbol c t -> Symbol d u
+mapSymbol fc ft = symbol (Cat . fc) (Tok . ft)
+
+filterCats :: [Symbol c t] -> [c]
+filterCats syms = [ cat | Cat cat <- syms ]
+
+filterToks :: [Symbol c t] -> [t]
+filterToks syms = [ tok | Tok tok <- syms ]
+
+
+------------------------------------------------------------
+-- * edges
+
+data Edge s = Edge Int Int s
+	      deriving (Eq, Ord, Show)
+
+instance Functor Edge where
+    fmap f (Edge i j s) = Edge i j (f s)
+
+
+------------------------------------------------------------
+-- * representaions of input tokens
+
+data Input t = MkInput { inputEdges  :: [Edge t],
+			 inputBounds :: (Int, Int),
+			 inputFrom   :: Array Int (Assoc t [Int]),
+			 inputTo     :: Array Int (Assoc t [Int]),
+			 inputToken  :: Assoc t [(Int, Int)]
+		       }
+
+makeInput :: Ord t => [Edge t] -> Input t
+input     :: Ord t =>  [t]     -> Input t
+inputMany :: Ord t => [[t]]    -> Input t
+
+instance Show t => Show (Input t) where
+    show input = "makeInput " ++ show (inputEdges input)
+
+----------
+
+makeInput inEdges  | null inEdges = input []
+		   | otherwise    = MkInput inEdges inBounds inFrom inTo inToken
+    where inBounds = foldr1 minmax [ (i, j) | Edge i j _ <- inEdges ]
+	      where minmax (a, b) (a', b') = (min a a', max b b')
+	  inFrom   = fmap (accumAssoc id) $ accumArray (<++>) [] inBounds $
+		     [ (i, [(tok, j)]) | Edge i j tok <- inEdges ]
+	  inTo     = fmap (accumAssoc id) $ accumArray (<++>) [] inBounds
+		     [ (j, [(tok, i)]) | Edge i j tok <- inEdges ]
+	  inToken  = accumAssoc id [ (tok, (i, j)) | Edge i j tok <- inEdges ]
+
+input toks         = MkInput inEdges inBounds inFrom inTo inToken
+    where inEdges  = zipWith3 Edge [0..] [1..] toks
+	  inBounds = (0, length toks)
+	  inFrom   = listArray inBounds $
+		     [ listAssoc [(tok, [j])] | (tok, j) <- zip toks [1..] ] ++ [ listAssoc [] ]
+	  inTo     = listArray inBounds $
+		     [ listAssoc [] ] ++ [ listAssoc [(tok, [i])] | (tok, i) <- zip toks [0..] ]
+	  inToken  = accumAssoc id [ (tok, (i, j)) | Edge i j tok <- inEdges ]
+
+inputMany toks     = MkInput inEdges inBounds inFrom inTo inToken
+    where inEdges  = [ Edge i j t | (i, j, ts) <- zip3 [0..] [1..] toks, t <- ts ]
+	  inBounds = (0, length toks)
+	  inFrom   = listArray inBounds $
+		     [ listAssoc [ (t, [j]) | t <- nubsort ts ] | (ts, j) <- zip toks [1..] ]
+		     ++ [ listAssoc [] ]
+	  inTo     = listArray inBounds $
+		     [ listAssoc [] ] ++ 
+		     [ listAssoc [ (t, [i]) | t <- nubsort ts ] | (ts, i) <- zip toks [0..] ]
+	  inToken  = accumAssoc id [ (tok, (i, j)) | Edge i j tok <- inEdges ]
+
+
+------------------------------------------------------------
+-- * charts, forests & trees
+
+-- | The values of the chart, a list of key-daughters pairs,
+-- has unique keys. In essence, it is a map from 'n' to daughters.
+-- The daughters should be a set (not necessarily sorted) of rhs's.
+type SyntaxChart n e = Assoc e [(n, [[e]])]
+
+-- better(?) representation of forests:
+-- data Forest n = F (SMap n (SList [Forest n])) Bool
+-- ==
+-- type Forest n = GeneralTrie n (SList [Forest n]) Bool
+-- (the Bool == isMeta)
+
+data SyntaxForest n = FMeta 
+		    | FNode n [[SyntaxForest n]]
+                      -- ^ The outer list should be a set (not necessarily sorted)
+		      -- of possible alternatives. Ie. the outer list 
+		      -- is a disjunctive node, and the inner lists 
+		      -- are (conjunctive) concatenative nodes
+		      deriving (Eq, Ord, Show)
+
+data SyntaxTree n = TMeta | TNode n [SyntaxTree n] 
+		    deriving (Eq, Ord, Show)
+
+forestName :: SyntaxForest n -> Maybe n
+forestName (FNode n _) = Just n
+forestName (FMeta)     = Nothing
+
+treeName :: SyntaxTree n -> Maybe n
+treeName (TNode n _) = Just n
+treeName (TMeta)     = Nothing
+
+instance Functor SyntaxTree where
+    fmap f (TNode n trees) = TNode (f n) $ map (fmap f) trees
+    fmap f (TMeta) = TMeta 
+
+instance Functor SyntaxForest where
+    fmap f (FNode n forests) = FNode (f n) $ map (map (fmap f)) forests
+    fmap f (FMeta) = FMeta 
+
+{- måste tänka mer på detta:
+compactForests :: Ord n => [SyntaxForest n] -> SList (SyntaxForest n)
+compactForests = map joinForests . groupBy eqNames . sortForests
+    where eqNames f g    = forestName f == forestName g
+	  sortForests    = foldMerge mergeForests [] . map return 
+	  mergeForests [] gs = gs
+	  mergeForests fs [] = fs
+	  mergeForests fs@(f:fs') gs@(g:gs') 
+	      = case forestName f `compare` forestName g of
+		  LT ->     f : mergeForests fs' gs
+		  GT ->     g : mergeForests fs  gs'
+		  EQ -> f : g : mergeForests fs' gs'
+	  joinForests fs = case forestName (head fs) of
+			     Nothing   -> FMeta
+			     Just name -> FNode name $
+					  compactDaughters $
+					  concat [ fss | FNode _ fss <- fs ]
+	  compactDaughters fss = case head fss of
+				   []  -> [[]]
+				   [_] -> map return $ compactForests $ concat fss
+				   _   -> nubsort fss
+-}
+
+-- ** conversions between representations
+
+forest2trees :: SyntaxForest n -> SList (SyntaxTree n)
+forest2trees (FNode n forests) = map (TNode n) $ forests >>= mapM forest2trees
+forest2trees (FMeta) = [TMeta]
+
+chart2forests :: (Ord n, Ord e) => 
+		 SyntaxChart n e  -- ^ The complete chart
+	      -> (e -> Bool)      -- ^ When is an edge 'FMeta'?
+	      -> [e]              -- ^ The starting edges
+	      -> SList (SyntaxForest n) -- ^ The result has unique keys, ie. all 'n' are joined together.
+					-- In essence, the result is a map from 'n' to forest daughters
+
+-- simplest implementation
+chart2forests chart isMeta  = concatMap edge2forests
+    where edge2forests edge = if isMeta edge then [FMeta]
+			      else map item2forest $ chart ? edge
+	  item2forest (name, children) = FNode name $ children >>= mapM edge2forests
+
+{-
+-- more intelligent(?) implementation,
+-- requiring that charts and forests are sorted maps and sorted sets
+chart2forests chart isMeta = es2fs
+    where e2fs  e  = if isMeta e then [FMeta] else map i2f $ chart ? e
+	  es2fs es = if null metas then fs else FMeta : fs
+	      where (metas, nonMetas) = splitBy isMeta es
+		    fs = map i2f $ unionMap (<++>) $ map (chart ?) nonMetas
+	  i2f (name, children) = FNode name $ 
+				 case head children of
+				   []  -> [[]]
+				   [_] -> map return $ es2fs $ concat children
+				   _   -> children >>= mapM e2fs
+-}
+
+
+-- ** operations on forests
+
+unifyManyForests :: (Monad m, Eq n) => [SyntaxForest n] -> m (SyntaxForest n)
+unifyManyForests = foldM unifyForests FMeta
+
+-- | two forests can be unified, if either is 'FMeta', or both have the same parent, 
+-- and all children can be unified
+unifyForests :: (Monad m, Eq n) => SyntaxForest n -> SyntaxForest n -> m (SyntaxForest n)
+unifyForests FMeta  forest = return forest
+unifyForests forest FMeta  = return forest
+unifyForests (FNode name1 children1) (FNode name2 children2)
+    | name1 == name2 && not (null children) = return $ FNode name1 children
+    | otherwise    = fail "forest unification failure"
+    where children = [ forests | forests1 <- children1, forests2 <- children2,
+		       sameLength forests1 forests2,
+		       forests <- zipWithM unifyForests forests1 forests2 ]
+
+
+-- ** operations on trees 
+
+unifyManyTrees :: (Monad m, Eq n) => [SyntaxTree n] -> m (SyntaxTree n)
+unifyManyTrees = foldM unifyTrees TMeta
+
+-- | two trees can be unified, if either is 'TMeta', 
+-- or both have the same parent, and their children can be unified
+unifyTrees :: (Monad m, Eq n) => SyntaxTree n -> SyntaxTree n -> m (SyntaxTree n)
+unifyTrees TMeta tree = return tree
+unifyTrees tree TMeta = return tree
+unifyTrees (TNode name1 children1) (TNode name2 children2)
+    | name1 == name2 && sameLength children1 children2 
+	= liftM (TNode name1) $ zipWithM unifyTrees children1 children2 
+    | otherwise = fail "tree unification failure"
+
+
+
+------------------------------------------------------------
+-- pretty-printing
+
+instance (Print c, Print t) => Print (Symbol c t) where
+    prt = symbol prt (simpleShow . prt)
+	where simpleShow str = "\"" ++ concatMap mkEsc str ++ "\""
+	      mkEsc '\\' = "\\\\"
+	      mkEsc '\"' = "\\\""
+	      mkEsc '\n' = "\\n"
+	      mkEsc '\t' = "\\t"
+	      mkEsc chr  = [chr]
+    prtList = prtSep " "
+
+instance Print t => Print (Input t) where
+    prt input = "input " ++ prt (inputEdges input)
+
+instance (Print s) => Print (Edge s) where
+    prt (Edge i j s) = "[" ++ show i ++ "-" ++ show j ++ ": " ++ prt s ++ "]"
+    prtList = prtSep ""
+
+instance (Print s) => Print (SyntaxTree s) where
+    prt (TNode s trees) = prt s ++ "^{" ++ prtSep " " trees ++ "}"
+    prt (TMeta) = "?"
+    prtList = prtAfter "\n"
+
+instance (Print s) => Print (SyntaxForest s) where
+    prt (FNode s forests) = prt s ++ "^{" ++ prtSep " | " (map (prtSep " ") forests) ++ "}"
+    prt (FMeta) = "?"
+    prtList = prtAfter "\n"
+
+