Merge pull request #6 from dancingrobot84/fix-satisfy

Broken satisfy

Author: paf31

examples/Test.purs

@@ -46,7 +46,13 @@ exprTest = buildExprParser [[Infix (string "/" >>= \_ -> return (/)) AssocRight]
                            ,[Infix (string "*" >>= \_ -> return (*)) AssocRight]
                            ,[Infix (string "-" >>= \_ -> return (-)) AssocRight]
                            ,[Infix (string "+" >>= \_ -> return (+)) AssocRight]] digit
-              
+
+manySatisfyTest :: Parser String [String]
+manySatisfyTest = do
+    r <- many1 $ satisfy (\s -> s /= "?")
+    string "?"
+    return r
+
 main = do
   parseTest nested "(((a)))"
   parseTest (many (string "a")) "aaa"
@@ -60,3 +66,4 @@ main = do
     return as) "a,a,a,"  
   parseTest opTest "a+b+c"
   parseTest exprTest "1*2+3/4-5"
+  parseTest manySatisfyTest "ab?"

src/Text/Parsing/Parser/String.purs

@@ -34,9 +34,10 @@ char = ParserT $ \s' ->
     _ -> { consumed: true, input: drop 1 s', result: Right (charAt 0 s') }
 
 satisfy :: forall m. (Monad m) => (String -> Boolean) -> ParserT String m String
-satisfy f = do
-  p <- char
-  if f p then return p else fail "Character did not satisfy predicate"
+satisfy f = try do
+    c <- char
+    if f c then return c
+           else fail "Character did not satisfy predicate"
 
 whiteSpace :: forall m. (Monad m) => ParserT String m String
 whiteSpace = do