StatusCode is now a type class, not an algebraic data type.

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

diff --git a/Network/HTTP/Lucu/Utils.hs b/Network/HTTP/Lucu/Utils.hs
index 5dc1584683b5b23082cc3ae63cbd57ad293fe2e2..d6e571dd0fcf3ab0a2ad30c4cd1ac8188516d96c 100644 (file)
--- a/Network/HTTP/Lucu/Utils.hs
+++ b/Network/HTTP/Lucu/Utils.hs
@@ -1,52 +1,125 @@
+{-# LANGUAGE
+    OverloadedStrings
+  , TemplateHaskell
+  , UnicodeSyntax
+  #-}
+-- |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]]
-    , joinWith     -- [a] -> [[a]] -> [a]
-    , trim         -- (a -> Bool) -> [a] -> [a]
-    , noCaseEq     -- String -> String -> Bool
-    , isWhiteSpace -- Char -> Bool
-    , quoteStr     -- String -> String
+    ( splitBy
+    , quoteStr
+    , parseWWWFormURLEncoded
+    , splitPathInfo
+    , trim
+    , liftCIAscii
+    , liftText
+    , liftMap
     )
     where
-
-import Control.Monad.Trans
+import Control.Monad
+import Data.Ascii (Ascii, CIAscii, AsciiBuilder)
+import qualified Data.Ascii as A
+import Data.ByteString (ByteString)
+import qualified Data.ByteString.Char8 as BS
 import Data.Char
-import Data.List
-import Foreign
-import Foreign.C
+import Data.List hiding (last)
+import Data.Map (Map)
+import qualified Data.Map as M
+import Data.Monoid.Unicode
+import Data.Text (Text)
+import qualified Data.Text as T
+import Language.Haskell.TH.Lib
+import Language.Haskell.TH.Syntax
 import Network.URI
+import Prelude hiding (last)
+import Prelude.Unicode
 
+-- |>>> splitBy (== ':') "ab:c:def"
+-- ["ab", "c", "def"]
+splitBy ∷ (a → Bool) → [a] → [[a]]
+{-# INLINEABLE splitBy #-}
+splitBy isSep src
+    = case break isSep src of
+        (last , []       ) → [last]
+        (first, _sep:rest) → first : splitBy isSep rest
 
-splitBy :: (a -> Bool) -> [a] -> [[a]]
-splitBy isSeparator src
-    = case break isSeparator src
-      of (last , []      ) -> last  : []
-         (first, sep:rest) -> first : splitBy isSeparator rest
-
-
-joinWith :: [a] -> [[a]] -> [a]
-joinWith separator xs
-    = foldr (++) [] $ intersperse separator xs
+-- |>>> quoteStr "abc"
+-- "\"abc\""
+--
+-- >>> quoteStr "ab\"c"
+-- "\"ab\\\"c\""
+quoteStr ∷ Ascii → AsciiBuilder
+quoteStr str = A.toAsciiBuilder "\"" ⊕
+               go (A.toByteString str) (∅) ⊕
+               A.toAsciiBuilder "\""
+    where
+      go ∷ BS.ByteString → AsciiBuilder → AsciiBuilder
+      go bs ab
+          = case BS.break (≡ '"') bs of
+              (x, y)
+                  | BS.null y → ab ⊕ b2ab x
+                  | otherwise → go (BS.tail y) (ab ⊕ b2ab x
+                                                   ⊕ A.toAsciiBuilder "\\\"")
 
+      b2ab ∷ BS.ByteString → AsciiBuilder
+      b2ab = A.toAsciiBuilder ∘ A.unsafeFromByteString
 
-trim :: (a -> Bool) -> [a] -> [a]
-trim p = trimTail . trimHead
+-- |>>> parseWWWFormURLEncoded "aaa=bbb&ccc=ddd"
+-- [("aaa", "bbb"), ("ccc", "ddd")]
+parseWWWFormURLEncoded ∷ Ascii → [(ByteString, ByteString)]
+parseWWWFormURLEncoded src
+    -- THINKME: We could gain some performance by using attoparsec
+    -- here.
+    | src ≡ ""  = []
+    | otherwise = do pairStr ← splitBy (\ c → c ≡ ';' ∨ c ≡ '&') (A.toString src)
+                     let (key, value) = break (≡ '=') pairStr
+                     return ( unescape key
+                            , unescape $ case value of
+                                           ('=':val) → val
+                                           val       → val
+                            )
     where
-      trimHead = dropWhile p
-      trimTail = reverse . trimHead . reverse
+      unescape ∷ String → ByteString
+      unescape = BS.pack ∘ unEscapeString ∘ map plusToSpace
 
+      plusToSpace ∷ Char → Char
+      plusToSpace '+' = ' '
+      plusToSpace c   = c
 
-noCaseEq :: String -> String -> Bool
-noCaseEq a b
-    = (map toLower a) == (map toLower b)
+-- |>>> splitPathInfo "http://example.com/foo/bar"
+-- ["foo", "bar"]
+splitPathInfo ∷ URI → [ByteString]
+splitPathInfo uri
+    = let reqPathStr = uriPath uri
+          reqPath    = [unEscapeString x | x ← splitBy (≡ '/') reqPathStr, (¬) (null x)]
+      in
+        map BS.pack reqPath
 
+-- |>>> trim "  ab c d "
+-- "ab c d"
+trim ∷ String → String
+trim = reverse ∘ f ∘ reverse ∘ f
+    where
+      f = dropWhile isSpace
 
-isWhiteSpace :: Char -> Bool
-isWhiteSpace = flip elem " \t\r\n"
+-- |Convert a 'CIAscii' to an 'Exp' representing it as a literal.
+liftCIAscii ∷ CIAscii → Q Exp
+liftCIAscii a = [| A.toCIAscii (A.unsafeFromString $(strLit a)) |]
+    where
+      strLit ∷ CIAscii → Q Exp
+      strLit = liftString ∘ A.toString ∘ A.fromCIAscii
 
+-- |Convert a 'Text' to an 'Exp' representing it as a literal.
+liftText ∷ Text → Q Exp
+liftText t = [| T.pack $(strLit t) |]
+    where
+      strLit ∷ Text → Q Exp
+      strLit = liftString ∘ T.unpack
 
-quoteStr :: String -> String
-quoteStr str = foldr (++) "" (["\""] ++ map quote str ++ ["\""])
+-- |Convert an arbitrary 'Map' to an 'Exp' representing it as a
+-- literal, using a given key lifter and a value lifter.
+liftMap ∷ Eq k ⇒ (k → Q Exp) → (v → Q Exp) → Map k v → Q Exp
+liftMap liftK liftV m = [| M.fromAscList $(liftPairs $ M.toAscList m) |]
     where
-      quote :: Char -> String
-      quote '"' = "\\\""
-      quote c   = [c]
\ No newline at end of file
+      liftPairs       = listE ∘ map liftPair
+      liftPair (k, v) = tupE [liftK k, liftV v]