diff options
Diffstat (limited to 'src/GF/Grammar/PatternMatch.hs')
| -rw-r--r-- | src/GF/Grammar/PatternMatch.hs | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/src/GF/Grammar/PatternMatch.hs b/src/GF/Grammar/PatternMatch.hs index 804333b14..881f10198 100644 --- a/src/GF/Grammar/PatternMatch.hs +++ b/src/GF/Grammar/PatternMatch.hs @@ -29,8 +29,11 @@ import Control.Monad matchPattern :: [(Patt,Term)] -> Term -> Err (Term, Substitution) matchPattern pts term = - errIn ("trying patterns" +++ unwords (intersperse "," (map (prt . fst) pts))) $ - findMatch [([p],t) | (p,t) <- pts] [term] + if not (isInConstantForm term) + then prtBad "variables occur in" term + else + errIn ("trying patterns" +++ unwords (intersperse "," (map (prt . fst) pts))) $ + findMatch [([p],t) | (p,t) <- pts] [term] testOvershadow :: [Patt] -> [Term] -> Err [Patt] testOvershadow pts vs = do @@ -54,14 +57,15 @@ tryMatch (p,t) = do t' <- termForm t trym p t' where + isInConstantFormt = True -- tested already trym p t' = case (p,t') of (PVal _ i, (_,Val _ j,_)) | i == j -> return [] | otherwise -> Bad $ "no match of values" (_,(x,Empty,y)) -> trym p (x,K [],y) -- because "" = [""] = [] - (PV IW, _) | isInConstantForm t -> return [] -- optimization with wildcard - (PV x, _) | isInConstantForm t -> return [(x,t)] + (PV IW, _) | 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? |