Slight speed improvement

[Lucu.git] / Network / HTTP / Lucu / Parser.hs

diff --git a/Network/HTTP/Lucu/Parser.hs b/Network/HTTP/Lucu/Parser.hs
index 174a28997e04b85641392ea6062662f3705ed67d..80d7707f441ace9da97882f19d1e022d45a0bded 100644 (file)
--- a/Network/HTTP/Lucu/Parser.hs
+++ b/Network/HTTP/Lucu/Parser.hs
@@ -20,6 +20,8 @@ module Network.HTTP.Lucu.Parser
     ( Parser
     , ParserResult(..)
 
+    , failP
+
     , parse
     , parseStr
 
@@ -36,8 +38,6 @@ module Network.HTTP.Lucu.Parser
     , notFollowedBy
     , many
     , many1
-    , manyTill
-    , many1Till
     , count
     , option
     , sepBy
@@ -82,6 +82,10 @@ instance Monad Parser where
     return x = x `seq` Parser $! return $! Success x
     fail _   = Parser $! return $! IllegalInput
 
+-- |@'failP'@ is just a synonym for @'Prelude.fail Prelude.undefined'@.
+failP :: Parser a
+failP = fail undefined
+
 -- |@'parse' p bstr@ parses @bstr@ with @p@ and returns @(result,
 -- remaining)@.
 parse :: Parser a -> ByteString -> (ParserResult a, ByteString)
@@ -104,9 +108,8 @@ anyChar = Parser $!
              if B.null input then
                  return ReachedEOF
                else
-                 do let c = B.head input
-                    put (B.tail input, isEOFFatal)
-                    return (Success c)
+                 do put (B.tail input, isEOFFatal)
+                    return (Success $! B.head input)
 
 
 eof :: Parser ()
@@ -134,8 +137,10 @@ allowEOF f = f `seq`
 satisfy :: (Char -> Bool) -> Parser Char
 satisfy f = f `seq`
             do c <- anyChar
-               unless (f c) (fail "")
-               return c
+               if f c then
+                   return c
+                 else
+                   failP
 
 
 char :: Char -> Parser Char
@@ -169,12 +174,12 @@ f <|> g
 
 
 oneOf :: [Char] -> Parser Char
-oneOf = foldl (<|>) (fail "") . map char
+oneOf = foldl (<|>) failP . map char
 
 
 notFollowedBy :: Parser a -> Parser ()
 notFollowedBy p = p `seq`
-                  p >>= fail "" <|> return ()
+                  (p >> failP) <|> return ()
 
 
 digit :: Parser Char
@@ -182,7 +187,7 @@ digit = do c <- anyChar
            if c >= '0' && c <= '9' then
                return c
              else
-               fail ""
+               failP
 
 
 hexDigit :: Parser Char
@@ -192,7 +197,7 @@ hexDigit = do c <- anyChar
                  (c >= 'A' && c <= 'F') then
                   return c
                 else
-                  fail ""
+                  failP
 
 
 many :: Parser a -> Parser [a]
@@ -206,26 +211,9 @@ many p = p `seq`
 
 many1 :: Parser a -> Parser [a]
 many1 p = p `seq`
-          do ret <- many p
-             case ret of
-               [] -> fail ""
-               xs -> return xs
-
-
-manyTill :: Parser a -> Parser end -> Parser [a]
-manyTill p end
-    = p `seq` end `seq`
-      many $! do x <- p
-                 end
-                 return x
-
-
-many1Till :: Parser a -> Parser end -> Parser [a]
-many1Till p end
-    = p `seq` end `seq`
-      many1 $! do x <- p
-                  end
-                  return x
+          do x  <- p
+             xs <- many p
+             return (x:xs)
 
 
 count :: Int -> Parser a -> Parser [a]