61b5d8f · elk · git.iko.soy

Nicer messages on specific parse failures

commit61b5d8fbfa0a4749fcc71d46514ab03073a67667 authorEvan Czaplicki <info@elm-lang.org> dateTue 13 Aug 2013, 23:11 (13 years ago) parentab83c78

2 files changed+10−4

unifiedsplit

compiler/Parse/Binop.hs+4−4

@@ -80,21 +80,21 @@ splitLevel table n e eops =

8080joinL :: [LExpr t v] -> [String] -> IParser (LExpr t v)

8181joinL [e] [] = return e

8282joinL (a:b:es) (op:ops) = joinL (merge a b (Binop op a b) : es) ops

83−joinL _ _ = fail "Ill-formed binary expression. Report a compiler bug."

83+joinL _ _ = failure "Ill-formed binary expression. Report a compiler bug."

8484

8585joinR :: [LExpr t v] -> [String] -> IParser (LExpr t v)

8686joinR [e] [] = return e

8787joinR (a:b:es) (op:ops) = do e <- joinR (b:es) ops

8888 return (merge a e (Binop op a e))

89−joinR _ _ = fail "Ill-formed binary expression. Report a compiler bug."

89+joinR _ _ = failure "Ill-formed binary expression. Report a compiler bug."

9090

9191getAssoc :: OpTable -> Int -> [(String,LExpr t v)] -> IParser Assoc

9292getAssoc table n eops

9393 | all (==L) assocs = return L

9494 | all (==R) assocs = return R

9595 | all (==N) assocs = case assocs of [_] -> return N

96− _ -> fail (msg "precedence")

97− | otherwise = fail (msg "associativity")

96+ _ -> failure (msg "precedence")

97+ | otherwise = failure (msg "associativity")

9898 where levelOps = filter (hasLevel table n) eops

9999 assocs = map (opAssoc table . fst) levelOps

100100 msg problem =

compiler/Parse/Helpers.hs+6

@@ -116,6 +116,12 @@ constrainedSpacePrefix p constraint =

116116 indented

117117 p

118118

119+failure msg = do

120+ inp <- getInput

121+ setInput ('x':inp)

122+ anyToken

123+ fail msg

124+

119125followedBy a b = do x <- a ; b ; return x

120126

121127betwixt a b c = do char a ; out <- c