Cosmetic changes suggested by hlint

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

diff --git a/Network/HTTP/Lucu/Utils.hs b/Network/HTTP/Lucu/Utils.hs
index 7d6eeeb69531b73bede3d9e573c749c162c5e640..9212747d9cf4ea782491240f1c8e201c29715dc4 100644 (file)
--- a/Network/HTTP/Lucu/Utils.hs
+++ b/Network/HTTP/Lucu/Utils.hs
@@ -1,33 +1,75 @@
+-- |Utility functions used internally in the Lucu httpd. These
+-- functions may be useful too for something else.
 module Network.HTTP.Lucu.Utils
-    ( splitBy      -- (a -> Bool) -> [a] -> [[a]]
-    , trim         -- (a -> Bool) -> [a] -> [a]
-    , noCaseEq     -- String -> String -> Bool
-    , isWhiteSpace -- Char -> Bool
+    ( splitBy
+    , joinWith
+    , trim
+    , isWhiteSpace
+    , quoteStr
+    , parseWWWFormURLEncoded
     )
     where
 
-import Data.Char
-import Data.List
-
+import Data.List hiding (last)
+import Network.URI
+import Prelude hiding (last)
 
+-- |> splitBy (== ':') "ab:c:def"
+--  > ==> ["ab", "c", "def"]
 splitBy :: (a -> Bool) -> [a] -> [[a]]
-splitBy isSeparator src
-    = case break isSeparator src
-      of (last , []      ) -> last  : []
-         (first, sep:rest) -> first : splitBy isSeparator rest
+splitBy isSep src
+    = case break isSep src
+      of (last , []       ) -> [last]
+         (first, _sep:rest) -> first : splitBy isSep rest
 
+-- |> joinWith ":" ["ab", "c", "def"]
+--  > ==> "ab:c:def"
+joinWith :: [a] -> [[a]] -> [a]
+joinWith separator xs
+    = separator `seq` xs `seq`
+      foldr (++) [] $! intersperse separator xs
 
+-- |> trim (== '_') "__ab_c__def___"
+--  > ==> "ab_c__def"
 trim :: (a -> Bool) -> [a] -> [a]
-trim p = trimTail . trimHead
+trim p = p `seq` trimTail . trimHead
     where
       trimHead = dropWhile p
       trimTail = reverse . trimHead . reverse
 
+-- |@'isWhiteSpace' c@ is 'Prelude.True' iff c is one of SP, HT, CR
+-- and LF.
+isWhiteSpace :: Char -> Bool
+isWhiteSpace ' '  = True
+isWhiteSpace '\t' = True
+isWhiteSpace '\r' = True
+isWhiteSpace '\n' = True
+isWhiteSpace _    = False
+{-# INLINE isWhiteSpace #-}
 
-noCaseEq :: String -> String -> Bool
-noCaseEq a b
-    = (map toLower a) == (map toLower b)
+-- |> quoteStr "abc"
+--  > ==> "\"abc\""
+--
+--  > quoteStr "ab\"c"
+--  > ==> "\"ab\\\"c\""
+quoteStr :: String -> String
+quoteStr str = str `seq`
+               foldr (++) "" (["\""] ++ map quote str ++ ["\""])
+    where
+      quote :: Char -> String
+      quote '"' = "\\\""
+      quote c   = [c]
 
 
-isWhiteSpace :: Char -> Bool
-isWhiteSpace = flip elem " \t\r\n"
+-- |> parseWWWFormURLEncoded "aaa=bbb&ccc=ddd"
+--  > ==> [("aaa", "bbb"), ("ccc", "ddd")]
+parseWWWFormURLEncoded :: String -> [(String, String)]
+parseWWWFormURLEncoded src
+    | src == "" = []
+    | otherwise = do pairStr <- splitBy (\ c -> c == ';' || c == '&') src
+                     let (key, value) = break (== '=') pairStr
+                     return ( unEscapeString key
+                            , unEscapeString $ case value of
+                                                 ('=':val) -> val
+                                                 val       -> val
+                            )