Files
gf-core/src/PGF/Linearize.hs
2009-10-07 16:18:33 +00:00

160 lines
4.9 KiB
Haskell

module PGF.Linearize
(linearizes,realize,realizes,linTree, linTreeMark,linearizesMark) where
import PGF.CId
import PGF.Data
import PGF.Macros
import PGF.Tree
import Control.Monad
import qualified Data.Map as Map
import Data.List
import Debug.Trace
-- linearization and computation of concrete PGF Terms
linearizes :: PGF -> CId -> Expr -> [String]
linearizes pgf lang = realizes . linTree pgf lang
realize :: Term -> String
realize = concat . take 1 . realizes
realizes :: Term -> [String]
realizes = map (unwords . untokn) . realizest
realizest :: Term -> [[Tokn]]
realizest trm = case trm of
R ts -> realizest (ts !! 0)
S ss -> map concat $ combinations $ map realizest ss
K t -> [[t]]
W s t -> [[KS (s ++ r)] | [KS r] <- realizest t]
FV ts -> concatMap realizest ts
TM s -> [[KS s]]
_ -> [[KS $ "REALIZE_ERROR " ++ show trm]] ---- debug
untokn :: [Tokn] -> [String]
untokn ts = case ts of
KP d _ : [] -> d
KP d vs : ws -> let ss@(s:_) = untokn ws in sel d vs s ++ ss
KS s : ws -> s : untokn ws
[] -> []
where
sel d vs w = case [v | Alt v cs <- vs, any (\c -> isPrefixOf c w) cs] of
v:_ -> v
_ -> d
-- Lifts all variants to the top level (except those in macros).
liftVariants :: Term -> [Term]
liftVariants = f
where
f (R ts) = liftM R $ mapM f ts
f (P t1 t2) = liftM2 P (f t1) (f t2)
f (S ts) = liftM S $ mapM f ts
f (FV ts) = ts >>= f
f (W s t) = liftM (W s) $ f t
f t = return t
linTree :: PGF -> CId -> Expr -> Term
linTree pgf lang = lin . expr2tree
where
lin (Abs xs e ) = case lin e of
R ts -> R $ ts ++ (Data.List.map (kks . showCId . snd) xs)
TM s -> R $ (TM s) : (Data.List.map (kks . showCId . snd) xs)
lin (Fun fun es) = let argVariants = mapM (liftVariants . lin) es
in variants [compute pgf lang args $ look fun | args <- argVariants]
lin (Lit (LStr s)) = R [kks (show s)] -- quoted
lin (Lit (LInt i)) = R [kks (show i)]
lin (Lit (LFlt d)) = R [kks (show d)]
lin (Var x) = TM (showCId x)
lin (Meta i) = TM (show i)
look = lookLin pgf lang
variants :: [Term] -> Term
variants ts = case ts of
[t] -> t
_ -> FV ts
unvariants :: Term -> [Term]
unvariants t = case t of
FV ts -> ts
_ -> [t]
compute :: PGF -> CId -> [Term] -> Term -> Term
compute pgf lang args = comp where
comp trm = case trm of
P r p -> proj (comp r) (comp p)
W s t -> W s (comp t)
R ts -> R $ map comp ts
V i -> idx args i -- already computed
F c -> comp $ look c -- not computed (if contains argvar)
FV ts -> FV $ map comp ts
S ts -> S $ filter (/= S []) $ map comp ts
_ -> trm
look = lookOper pgf lang
idx xs i = if i > length xs - 1
then trace
("too large " ++ show i ++ " for\n" ++ unlines (map show xs) ++ "\n") tm0
else xs !! i
proj r p = case (r,p) of
(_, FV ts) -> FV $ map (proj r) ts
(FV ts, _ ) -> FV $ map (\t -> proj t p) ts
(W s t, _) -> kks (s ++ getString (proj t p))
_ -> comp $ getField r (getIndex p)
getString t = case t of
K (KS s) -> s
_ -> error ("ERROR in grammar compiler: string from "++ show t) "ERR"
getIndex t = case t of
C i -> i
TM _ -> 0 -- default value for parameter
_ -> trace ("ERROR in grammar compiler: index from " ++ show t) 666
getField t i = case t of
R rs -> idx rs i
TM s -> TM s
_ -> error ("ERROR in grammar compiler: field from " ++ show t) t
---------
-- markup with tree positions
linearizesMark :: PGF -> CId -> Expr -> [String]
linearizesMark pgf lang = realizes . linTreeMark pgf lang
linTreeMark :: PGF -> CId -> Expr -> Term
linTreeMark pgf lang = lin [] . expr2tree
where
lin p (Abs xs e ) = case lin p e of
R ts -> R $ ts ++ (Data.List.map (kks . showCId . snd) xs)
TM s -> R $ (TM s) : (Data.List.map (kks . showCId . snd) xs)
lin p (Fun fun es) =
let argVariants =
mapM (\ (i,e) -> liftVariants $ lin (sub p i) e) (zip [0..] es)
in variants [mark (fun,p) $ compute pgf lang args $ look fun |
args <- argVariants]
lin p (Lit (LStr s)) = mark p $ R [kks (show s)] -- quoted
lin p (Lit (LInt i)) = mark p $ R [kks (show i)]
lin p (Lit (LFlt d)) = mark p $ R [kks (show d)]
lin p (Var x) = mark p $ TM (showCId x)
lin p (Meta i) = mark p $ TM (show i)
look = lookLin pgf lang
mark :: Show a => a -> Term -> Term
mark p t = case t of
R ts -> R $ map (mark p) ts
FV ts -> R $ map (mark p) ts
S ts -> S $ bracket p ts
K s -> S $ bracket p [t]
W s (R ts) -> R [mark p $ kks (s ++ u) | K (KS u) <- ts]
_ -> t
-- otherwise in normal form
bracket p ts = [kks ("("++show p)] ++ ts ++ [kks ")"]
sub p i = p ++ [i]