Files
gf-core/src-3.0/PGF/Parsing/FCFG/Utilities.hs
2008-06-19 12:48:29 +00:00

188 lines
6.6 KiB
Haskell

----------------------------------------------------------------------
-- |
-- Maintainer : PL
-- Stability : (stable)
-- Portability : (portable)
--
-- > CVS $Date: 2005/05/13 12:40:19 $
-- > CVS $Author: peb $
-- > CVS $Revision: 1.6 $
--
-- Basic type declarations and functions for grammar formalisms
-----------------------------------------------------------------------------
module PGF.Parsing.FCFG.Utilities where
import Control.Monad
import Data.Array
import Data.List (groupBy)
import PGF.CId
import PGF.Data
import GF.Data.Assoc
import GF.Data.Utilities (sameLength, foldMerge, splitBy)
------------------------------------------------------------
-- ranges as single pairs
type RangeRec = [Range]
data Range = Range {-# UNPACK #-} !Int {-# UNPACK #-} !Int
| EmptyRange
deriving (Eq, Ord)
makeRange :: Int -> Int -> Range
makeRange = Range
concatRange :: Range -> Range -> [Range]
concatRange EmptyRange rng = return rng
concatRange rng EmptyRange = return rng
concatRange (Range i j) (Range j' k) = [Range i k | j==j']
minRange :: Range -> Int
minRange (Range i j) = i
maxRange :: Range -> Int
maxRange (Range i j) = j
------------------------------------------------------------
-- * representaions of input tokens
data Input t = MkInput { inputBounds :: (Int, Int),
inputToken :: Assoc t [Range]
}
input :: Ord t => [t] -> Input t
input toks = MkInput inBounds inToken
where
inBounds = (0, length toks)
inToken = accumAssoc id [ (tok, makeRange i j) | (i,j,tok) <- zip3 [0..] [1..] toks ]
inputMany :: Ord t => [[t]] -> Input t
inputMany toks = MkInput inBounds inToken
where
inBounds = (0, length toks)
inToken = accumAssoc id [ (tok, makeRange i j) | (i,j,ts) <- zip3 [0..] [1..] toks, tok <- ts ]
------------------------------------------------------------
-- * representations of syntactical analyses
-- ** charts as finite maps over edges
-- | 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 [SyntaxNode n [e]]
data SyntaxNode n e = SMeta
| SNode n [e]
| SString String
| SInt Integer
| SFloat Double
deriving (Eq,Ord)
groupSyntaxNodes :: Ord n => [SyntaxNode n e] -> [SyntaxNode n [e]]
groupSyntaxNodes [] = []
groupSyntaxNodes (SNode n0 es0:xs) = (SNode n0 (es0:ess)) : groupSyntaxNodes xs'
where
(ess,xs') = span xs
span [] = ([],[])
span xs@(SNode n es:xs')
| n0 == n = let (ess,xs) = span xs' in (es:ess,xs)
| otherwise = ([],xs)
groupSyntaxNodes (SString s:xs) = (SString s) : groupSyntaxNodes xs
groupSyntaxNodes (SInt n:xs) = (SInt n) : groupSyntaxNodes xs
groupSyntaxNodes (SFloat f:xs) = (SFloat f) : groupSyntaxNodes xs
-- ** syntax forests
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
| FString String
| FInt Integer
| FFloat Double
deriving (Eq, Ord, Show)
instance Functor SyntaxForest where
fmap f (FNode n forests) = FNode (f n) $ map (map (fmap f)) forests
fmap _ (FString s) = FString s
fmap _ (FInt n) = FInt n
fmap _ (FFloat f) = FFloat f
fmap _ (FMeta) = FMeta
forestName :: SyntaxForest n -> Maybe n
forestName (FNode n _) = Just n
forestName _ = Nothing
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
where children = [ forests | forests1 <- children1, forests2 <- children2,
sameLength forests1 forests2,
forests <- zipWithM unifyForests forests1 forests2 ]
unifyForests (FString s1) (FString s2)
| s1 == s2 = return $ FString s1
unifyForests (FInt n1) (FInt n2)
| n1 == n2 = return $ FInt n1
unifyForests (FFloat f1) (FFloat f2)
| f1 == f2 = return $ FFloat f1
unifyForests _ _ = fail "forest unification failure"
-- ** conversions between representations
chart2forests :: (Ord n, Ord e) =>
SyntaxChart n e -- ^ The complete chart
-> (e -> Bool) -- ^ When is an edge 'FMeta'?
-> [e] -- ^ The starting edges
-> [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
chart2forests chart isMeta = concatMap (edge2forests [])
where edge2forests edges edge
| isMeta edge = [FMeta]
| edge `elem` edges = []
| otherwise = map (item2forest (edge:edges)) $ chart ? edge
item2forest edges (SMeta) = FMeta
item2forest edges (SNode name children) =
FNode name $ children >>= mapM (edge2forests edges)
item2forest edges (SString s) = FString s
item2forest edges (SInt n) = FInt n
item2forest edges (SFloat f) = FFloat f
applyProfileToForest :: SyntaxForest (CId,[Profile]) -> [SyntaxForest CId]
applyProfileToForest (FNode (fun,profiles) children)
| fun == wildCId = concat chForests
| otherwise = [ FNode fun chForests | not (null chForests) ]
where chForests = concat [ mapM (unifyManyForests . map (forests !!)) profiles |
forests0 <- children,
forests <- mapM applyProfileToForest forests0 ]
applyProfileToForest (FString s) = [FString s]
applyProfileToForest (FInt n) = [FInt n]
applyProfileToForest (FFloat f) = [FFloat f]
applyProfileToForest (FMeta) = [FMeta]
forest2trees :: SyntaxForest CId -> [Tree]
forest2trees (FNode n forests) = map (Fun n) $ forests >>= mapM forest2trees
forest2trees (FString s) = [Lit (LStr s)]
forest2trees (FInt n) = [Lit (LInt n)]
forest2trees (FFloat f) = [Lit (LFlt f)]
forest2trees (FMeta) = [Meta 0]