Fixed breakage on GHC 6.10.1

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

diff --git a/Network/HTTP/Lucu/Parser.hs b/Network/HTTP/Lucu/Parser.hs
index cc12cd73733b636ce3270e8518d137ade2eb3266..90c52696fbb4293e95849e5335758d7a255913bd 100644 (file)
--- a/Network/HTTP/Lucu/Parser.hs
+++ b/Network/HTTP/Lucu/Parser.hs
@@ -1,7 +1,8 @@
--- |Yet another parser combinator. This is mostly a subset of Parsec
--- but there are some differences:
+-- |Yet another parser combinator. This is mostly a subset of
+-- "Text.ParserCombinators.Parsec" but there are some differences:
 --
--- * This parser works on ByteString instead of String.
+-- * This parser works on 'Data.ByteString.Base.LazyByteString'
+--   instead of 'Prelude.String'.
 --
 -- * Backtracking is the only possible behavior so there is no \"try\"
 --   action.
@@ -32,6 +33,7 @@ module Network.HTTP.Lucu.Parser
     , char
     , string
     , (<|>)
+    , choice
     , oneOf
     , digit
     , hexDigit
@@ -50,11 +52,10 @@ module Network.HTTP.Lucu.Parser
     where
 
 import           Control.Monad.State.Strict
-import qualified Data.ByteString.Lazy.Char8 as B
-import           Data.ByteString.Lazy.Char8 (ByteString)
+import qualified Data.ByteString.Lazy as Lazy (ByteString)
+import qualified Data.ByteString.Lazy.Char8 as B hiding (ByteString)
 
-
--- |@Parser a@ is obviously a parser which parses and returns @a@.
+-- |@'Parser' a@ is obviously a parser which parses and returns @a@.
 newtype Parser a = Parser {
       runParser :: State ParserState (ParserResult a)
     }
@@ -62,7 +63,7 @@ newtype Parser a = Parser {
 
 data ParserState
     = PST {
-        pstInput      :: ByteString
+        pstInput      :: Lazy.ByteString
       , pstIsEOFFatal :: !Bool
       }
     deriving (Eq, Show)
@@ -87,24 +88,25 @@ 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'@ 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)
+-- |@'parse' p bstr@ parses @bstr@ with @p@ and returns @(# result,
+-- remaining #)@.
+parse :: Parser a -> Lazy.ByteString -> (# ParserResult a, Lazy.ByteString #)
 parse p input -- input は lazy である必要有り。
     = p `seq`
       let (result, state') = runState (runParser p) (PST input True)
       in
-        result `seq` (result, pstInput state') -- pstInput state' も lazy である必要有り。
+        result `seq` (# result, pstInput state' #) -- pstInput state' も lazy である必要有り。
 
 -- |@'parseStr' p str@ packs @str@ and parses it.
-parseStr :: Parser a -> String -> (ParserResult a, ByteString)
+parseStr :: Parser a -> String -> (# ParserResult a, Lazy.ByteString #)
 parseStr p input
     = p `seq` -- input は lazy である必要有り。
-      parse p $! B.pack input
+      parse p (B.pack input)
 
 
 anyChar :: Parser Char
@@ -142,7 +144,7 @@ allowEOF f = f `seq`
 satisfy :: (Char -> Bool) -> Parser Char
 satisfy f = f `seq`
             do c <- anyChar
-               if f c then
+               if f $! c then
                    return c
                  else
                    failP
@@ -165,7 +167,7 @@ infixr 0 <|>
 (<|>) :: Parser a -> Parser a -> Parser a
 f <|> g
     = f `seq` g `seq`
-      Parser $! do saved <- get -- 状態を保存
+      Parser $! do saved  <- get -- 状態を保存
                    result <- runParser f
                    case result of
                      Success a    -> return $! Success a
@@ -178,13 +180,26 @@ f <|> g
                                             runParser g
 
 
+choice :: [Parser a] -> Parser a
+choice = foldl (<|>) failP
+
+
 oneOf :: [Char] -> Parser Char
 oneOf = foldl (<|>) failP . map char
 
 
 notFollowedBy :: Parser a -> Parser ()
-notFollowedBy p = p `seq`
-                  (p >> failP) <|> return ()
+notFollowedBy p
+    = p `seq`
+      Parser $! do saved  <- get -- 状態を保存
+                   result <- runParser p
+                   case result of
+                     Success _    -> do put saved -- 状態を復歸
+                                        return IllegalInput
+                     IllegalInput -> do put saved -- 状態を復歸
+                                        return $! Success ()
+                     ReachedEOF   -> do put saved -- 状態を復歸
+                                        return $! Success ()
 
 
 digit :: Parser Char