---------------------------------------------------------------------- -- | -- Maintainer : Krasimir Angelov -- Stability : (stable) -- Portability : (portable) -- -- MCFG parsing, the active algorithm ----------------------------------------------------------------------------- module PGF.Parsing.FCFG.Active (parse) where import GF.Data.Assoc import GF.Data.SortedList import GF.Data.Utilities import qualified GF.Data.MultiMap as MM import PGF.CId import PGF.Data import PGF.Tree import PGF.Parsing.FCFG.Utilities import PGF.BuildParser import Control.Monad (guard) import qualified Data.List as List import qualified Data.Map as Map import qualified Data.IntMap as IntMap import qualified Data.Set as Set import Data.Array.IArray import Debug.Trace ---------------------------------------------------------------------- -- * parsing type FToken = String makeFinalEdge cat 0 0 = (cat, [EmptyRange]) makeFinalEdge cat i j = (cat, [makeRange i j]) -- | the list of categories = possible starting categories parse :: String -> ParserInfo -> Type -> [FToken] -> [Expr] parse strategy pinfo (DTyp _ start _) toks = map (tree2expr) . nubsort $ filteredForests >>= forest2trees where inTokens = input toks starts = Map.findWithDefault [] start (startCats pinfo) schart = xchart2syntaxchart chart pinfo (i,j) = inputBounds inTokens finalEdges = [makeFinalEdge cat i j | cat <- starts] forests = chart2forests schart (const False) finalEdges filteredForests = forests >>= applyProfileToForest pinfoex = buildParserInfo pinfo chart = process strategy pinfo pinfoex inTokens axioms emptyXChart axioms | isBU strategy = literals pinfoex inTokens ++ initialBU pinfo pinfoex inTokens | isTD strategy = literals pinfoex inTokens ++ initialTD pinfo starts inTokens isBU s = s=="b" isTD s = s=="t" -- used in prediction emptyChildren :: FunId -> [FCat] -> SyntaxNode FunId RangeRec emptyChildren ruleid args = SNode ruleid (replicate (length args) []) process :: String -> ParserInfo -> ParserInfoEx -> Input FToken -> [Item] -> XChart FCat -> XChart FCat process strategy pinfo pinfoex toks [] chart = chart process strategy pinfo pinfoex toks (item:items) chart = process strategy pinfo pinfoex toks items $! univRule item chart where univRule item@(Active found rng lbl ppos node@(SNode ruleid recs) args cat) chart | inRange (bounds lin) ppos = case lin ! ppos of FSymCat d r -> let c = args !! d in case recs !! d of [] -> case insertXChart chart item c of Nothing -> chart Just chart -> let items = do item@(Final found' _ _ _) <- lookupXChartFinal chart c rng <- concatRange rng (found' !! r) return (Active found rng lbl (ppos+1) (SNode ruleid (updateNth (const found') d recs)) args cat) ++ do guard (isTD strategy) (ruleid,args) <- topdownRules pinfo c return (Active [] EmptyRange 0 0 (emptyChildren ruleid args) args c) in process strategy pinfo pinfoex toks items chart found' -> let items = do rng <- concatRange rng (found' !! r) return (Active found rng lbl (ppos+1) node args cat) in process strategy pinfo pinfoex toks items chart FSymKS [tok] -> let items = do t_rng <- inputToken toks ? tok rng' <- concatRange rng t_rng return (Active found rng' lbl (ppos+1) node args cat) in process strategy pinfo pinfoex toks items chart | otherwise = if inRange (bounds lins) (lbl+1) then univRule (Active (rng:found) EmptyRange (lbl+1) 0 node args cat) chart else univRule (Final (reverse (rng:found)) node args cat) chart where (FFun _ _ lins) = functions pinfo ! ruleid lin = sequences pinfo ! (lins ! lbl) univRule item@(Final found' node args cat) chart = case insertXChart chart item cat of Nothing -> chart Just chart -> let items = do (Active found rng l ppos node@(SNode ruleid _) args c) <- lookupXChartAct chart cat let FFun _ _ lins = functions pinfo ! ruleid FSymCat d r = (sequences pinfo ! (lins ! l)) ! ppos rng <- concatRange rng (found' !! r) return (Active found rng l (ppos+1) (updateChildren node d found') args c) ++ do guard (isBU strategy) (ruleid,args,c) <- leftcornerCats pinfoex ? cat let FFun _ _ lins = functions pinfo ! ruleid FSymCat d r = (sequences pinfo ! (lins ! 0)) ! 0 return (Active [] (found' !! r) 0 1 (updateChildren (emptyChildren ruleid args) d found') args c) updateChildren :: SyntaxNode FunId RangeRec -> Int -> RangeRec -> SyntaxNode FunId RangeRec updateChildren (SNode ruleid recs) i rec = SNode ruleid $! updateNth (const rec) i recs in process strategy pinfo pinfoex toks items chart ---------------------------------------------------------------------- -- * XChart data Item = Active RangeRec Range {-# UNPACK #-} !FIndex {-# UNPACK #-} !FPointPos (SyntaxNode FunId RangeRec) [FCat] FCat | Final RangeRec (SyntaxNode FunId RangeRec) [FCat] FCat deriving (Eq, Ord, Show) data XChart c = XChart !(MM.MultiMap c Item) !(MM.MultiMap c Item) emptyXChart :: Ord c => XChart c emptyXChart = XChart MM.empty MM.empty insertXChart (XChart actives finals) item@(Active _ _ _ _ _ _ _) c = case MM.insert' c item actives of Nothing -> Nothing Just actives -> Just (XChart actives finals) insertXChart (XChart actives finals) item@(Final _ _ _ _) c = case MM.insert' c item finals of Nothing -> Nothing Just finals -> Just (XChart actives finals) lookupXChartAct (XChart actives finals) c = actives MM.! c lookupXChartFinal (XChart actives finals) c = finals MM.! c xchart2syntaxchart :: XChart FCat -> ParserInfo -> SyntaxChart (CId,[Profile]) (FCat,RangeRec) xchart2syntaxchart (XChart actives finals) pinfo = accumAssoc groupSyntaxNodes $ [ case node of SNode ruleid rrecs -> let FFun fun prof _ = functions pinfo ! ruleid in ((cat,found), SNode (fun,prof) (zip rhs rrecs)) SString s -> ((cat,found), SString s) SInt n -> ((cat,found), SInt n) SFloat f -> ((cat,found), SFloat f) | (Final found node rhs cat) <- MM.elems finals ] literals :: ParserInfoEx -> Input FToken -> [Item] literals pinfoex toks = [let (c,node) = lexer t in (Final [rng] node [] c) | (t,rngs) <- aAssocs (inputToken toks), rng <- rngs, not (t `elem` grammarToks pinfoex)] where lexer t = case reads t of [(n,"")] -> (fcatInt, SInt (n::Integer)) _ -> case reads t of [(f,"")] -> (fcatFloat, SFloat (f::Double)) _ -> (fcatString,SString t) ---------------------------------------------------------------------- -- Earley -- -- called with all starting categories initialTD :: ParserInfo -> [FCat] -> Input FToken -> [Item] initialTD pinfo starts toks = do cat <- starts (ruleid,args) <- topdownRules pinfo cat return (Active [] (Range 0 0) 0 0 (emptyChildren ruleid args) args cat) topdownRules pinfo cat = f cat [] where f cat rules = maybe rules (Set.fold g rules) (IntMap.lookup cat (productions pinfo)) g (FApply ruleid args) rules = (ruleid,args) : rules g (FCoerce cat) rules = f cat rules ---------------------------------------------------------------------- -- Kilbury -- initialBU :: ParserInfo -> ParserInfoEx -> Input FToken -> [Item] initialBU pinfo pinfoex toks = do (tok,rngs) <- aAssocs (inputToken toks) (ruleid,args,cat) <- leftcornerTokens pinfoex ? tok rng <- rngs return (Active [] rng 0 1 (emptyChildren ruleid args) args cat) ++ do (ruleid,args,cat) <- epsilonRules pinfoex let FFun _ _ _ = functions pinfo ! ruleid return (Active [] EmptyRange 0 0 (emptyChildren ruleid args) args cat)