summaryrefslogtreecommitdiff
path: root/src/GF/Grammar/PatternMatch.hs
diff options
context:
space:
mode:
authorkrasimir <krasimir@chalmers.se>2009-12-13 18:50:29 +0000
committerkrasimir <krasimir@chalmers.se>2009-12-13 18:50:29 +0000
commitf85232947e74ee7ef8c7b0ad2338212e7e68f1be (patch)
tree667b886a5e3a4b026a63d4e3597f32497d824761 /src/GF/Grammar/PatternMatch.hs
parentd88a865faff59c98fc91556ff8700b10ee5f2df8 (diff)
reorganize the directories under src, and rescue the JavaScript interpreter from deprecated
Diffstat (limited to 'src/GF/Grammar/PatternMatch.hs')
-rw-r--r--src/GF/Grammar/PatternMatch.hs165
1 files changed, 0 insertions, 165 deletions
diff --git a/src/GF/Grammar/PatternMatch.hs b/src/GF/Grammar/PatternMatch.hs
deleted file mode 100644
index b8f7eff7d..000000000
--- a/src/GF/Grammar/PatternMatch.hs
+++ /dev/null
@@ -1,165 +0,0 @@
-----------------------------------------------------------------------
--- |
--- Module : PatternMatch
--- Maintainer : AR
--- Stability : (stable)
--- Portability : (portable)
---
--- > CVS $Date: 2005/10/12 12:38:29 $
--- > CVS $Author: aarne $
--- > CVS $Revision: 1.7 $
---
--- pattern matching for both concrete and abstract syntax. AR -- 16\/6\/2003
------------------------------------------------------------------------------
-
-module GF.Grammar.PatternMatch (matchPattern,
- testOvershadow,
- findMatch
- ) where
-
-import GF.Data.Operations
-import GF.Grammar.Grammar
-import GF.Infra.Ident
-import GF.Grammar.Macros
-import GF.Grammar.Printer
-
-import Data.List
-import Control.Monad
-import Text.PrettyPrint
-import Debug.Trace
-
-matchPattern :: [(Patt,Term)] -> Term -> Err (Term, Substitution)
-matchPattern pts term =
- if not (isInConstantForm term)
- then Bad (render (text "variables occur in" <+> ppTerm Unqualified 0 term))
- else do
- term' <- mkK term
- errIn (render (text "trying patterns" <+> hsep (punctuate comma (map (ppPatt Unqualified 0 . fst) pts)))) $
- findMatch [([p],t) | (p,t) <- pts] [term']
- where
- -- to capture all Str with string pattern matching
- mkK s = case s of
- C _ _ -> do
- s' <- getS s
- return (K (unwords s'))
- _ -> return s
-
- getS s = case s of
- K w -> return [w]
- C v w -> liftM2 (++) (getS v) (getS w)
- Empty -> return []
- _ -> Bad (render (text "cannot get string from" <+> ppTerm Unqualified 0 s))
-
-testOvershadow :: [Patt] -> [Term] -> Err [Patt]
-testOvershadow pts vs = do
- let numpts = zip pts [0..]
- let cases = [(p,EInt i) | (p,i) <- numpts]
- ts <- mapM (liftM fst . matchPattern cases) vs
- return [p | (p,i) <- numpts, notElem i [i | EInt i <- ts] ]
-
-findMatch :: [([Patt],Term)] -> [Term] -> Err (Term, Substitution)
-findMatch cases terms = case cases of
- [] -> Bad (render (text "no applicable case for" <+> hsep (punctuate comma (map (ppTerm Unqualified 0) terms))))
- (patts,_):_ | length patts /= length terms ->
- Bad (render (text "wrong number of args for patterns :" <+> hsep (map (ppPatt Unqualified 0) patts) <+>
- text "cannot take" <+> hsep (map (ppTerm Unqualified 0) terms)))
- (patts,val):cc -> case mapM tryMatch (zip patts terms) of
- Ok substs -> return (val, concat substs)
- _ -> findMatch cc terms
-
-tryMatch :: (Patt, Term) -> Err [(Ident, Term)]
-tryMatch (p,t) = do
- t' <- termForm t
- trym p t'
- where
-
- isInConstantFormt = True -- tested already in matchPattern
- trym p t' =
- case (p,t') of
- (_,(x,Empty,y)) -> trym p (x,K [],y) -- because "" = [""] = []
- (PW, _) | isInConstantFormt -> return [] -- optimization with wildcard
- (PV x, _) | isInConstantFormt -> return [(x,t)]
- (PString s, ([],K i,[])) | s==i -> return []
- (PInt s, ([],EInt i,[])) | s==i -> return []
- (PFloat s,([],EFloat i,[])) | s==i -> return [] --- rounding?
- (PC p pp, ([], Con f, tt)) |
- p `eqStrIdent` f && length pp == length tt ->
- do matches <- mapM tryMatch (zip pp tt)
- return (concat matches)
-
- (PP q p pp, ([], QC r f, tt)) |
- -- q `eqStrIdent` r && --- not for inherited AR 10/10/2005
- p `eqStrIdent` f && length pp == length tt ->
- do matches <- mapM tryMatch (zip pp tt)
- return (concat matches)
- ---- hack for AppPredef bug
- (PP q p pp, ([], Q r f, tt)) |
- -- q `eqStrIdent` r && ---
- p `eqStrIdent` f && length pp == length tt ->
- do matches <- mapM tryMatch (zip pp tt)
- return (concat matches)
-
- (PR r, ([],R r',[])) |
- all (`elem` map fst r') (map fst r) ->
- do matches <- mapM tryMatch
- [(p,snd a) | (l,p) <- r, let Just a = lookup l r']
- return (concat matches)
- (PT _ p',_) -> trym p' t'
-
- (PAs x p',_) -> do
- subst <- trym p' t'
- return $ (x,t) : subst
-
- (PAlt p1 p2,_) -> checks [trym p1 t', trym p2 t']
-
- (PNeg p',_) -> case tryMatch (p',t) of
- Bad _ -> return []
- _ -> Bad (render (text "no match with negative pattern" <+> ppPatt Unqualified 0 p))
-
- (PSeq p1 p2, ([],K s, [])) -> do
- let cuts = [splitAt n s | n <- [0 .. length s]]
- matches <- checks [mapM tryMatch [(p1,K s1),(p2,K s2)] | (s1,s2) <- cuts]
- return (concat matches)
-
- (PRep p1, ([],K s, [])) -> checks [
- trym (foldr (const (PSeq p1)) (PString "")
- [1..n]) t' | n <- [0 .. length s]
- ] >>
- return []
-
- (PChar, ([],K [_], [])) -> return []
- (PChars cs, ([],K [c], [])) | elem c cs -> return []
-
- _ -> Bad (render (text "no match in case expr for" <+> ppTerm Unqualified 0 t))
-
-isInConstantForm :: Term -> Bool
-isInConstantForm trm = case trm of
- Cn _ -> True
- Con _ -> True
- Q _ _ -> True
- QC _ _ -> True
- Abs _ _ _ -> True
- C c a -> isInConstantForm c && isInConstantForm a
- App c a -> isInConstantForm c && isInConstantForm a
- R r -> all (isInConstantForm . snd . snd) r
- K _ -> True
- Empty -> True
- EInt _ -> True
- _ -> False ---- isInArgVarForm trm
-
-varsOfPatt :: Patt -> [Ident]
-varsOfPatt p = case p of
- PV x -> [x]
- PC _ ps -> concat $ map varsOfPatt ps
- PP _ _ ps -> concat $ map varsOfPatt ps
- PR r -> concat $ map (varsOfPatt . snd) r
- PT _ q -> varsOfPatt q
- _ -> []
-
--- | to search matching parameter combinations in tables
-isMatchingForms :: [Patt] -> [Term] -> Bool
-isMatchingForms ps ts = all match (zip ps ts') where
- match (PC c cs, (Cn d, ds)) = c == d && isMatchingForms cs ds
- match _ = True
- ts' = map appForm ts
-