Code clean-up using convertible-text.

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

diff --git a/Network/HTTP/Lucu/Utils.hs b/Network/HTTP/Lucu/Utils.hs
index d6e571dd0fcf3ab0a2ad30c4cd1ac8188516d96c..7537eafcffacf7d8edf755e2bb8fea30cd636547 100644 (file)
--- a/Network/HTTP/Lucu/Utils.hs
+++ b/Network/HTTP/Lucu/Utils.hs
@@ -1,38 +1,63 @@
 {-# LANGUAGE
-    OverloadedStrings
-  , TemplateHaskell
+    FlexibleContexts
+  , OverloadedStrings
   , UnicodeSyntax
   #-}
--- |Utility functions used internally in the Lucu httpd. These
--- functions may be useful too for something else.
+-- |Utility functions used internally in this package.
 module Network.HTTP.Lucu.Utils
-    ( splitBy
+    ( Host
+    , PathSegment
+    , Path
+
+    , splitBy
     , quoteStr
     , parseWWWFormURLEncoded
-    , splitPathInfo
+    , uriHost
+    , uriPathSegments
     , trim
-    , liftCIAscii
-    , liftText
-    , liftMap
+
+    , (⊲)
+    , (⊳)
+    , (⋈)
+    , mapM
+
+    , getLastModified
     )
     where
-import Control.Monad
-import Data.Ascii (Ascii, CIAscii, AsciiBuilder)
+import Control.Applicative hiding (empty)
+import Control.Monad hiding (mapM)
+import Data.Ascii (Ascii, AsciiBuilder)
 import qualified Data.Ascii as A
 import Data.ByteString (ByteString)
 import qualified Data.ByteString.Char8 as BS
+import Data.CaseInsensitive (CI)
+import qualified Data.CaseInsensitive as CI
 import Data.Char
-import Data.List hiding (last)
-import Data.Map (Map)
-import qualified Data.Map as M
+import Data.Collections
+import Data.Collections.BaseInstances ()
+import Data.Convertible.Base
+import Data.Convertible.Instances.Ascii ()
+import Data.Convertible.Instances.Text ()
+import Data.Convertible.Instances.Time ()
+import Data.Maybe
 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 Data.Time
 import Network.URI
-import Prelude hiding (last)
+import Prelude hiding (last, mapM, null, reverse)
 import Prelude.Unicode
+import System.Directory
+
+-- |'Host' represents an IP address or a host name in an URI
+-- authority.
+type Host = CI Text
+
+-- |'PathSegment' represents an URI path segment, split by slashes and
+-- percent-decoded.
+type PathSegment = ByteString
+
+-- |'Path' is a list of URI path segments.
+type Path = [PathSegment]
 
 -- |>>> splitBy (== ':') "ab:c:def"
 -- ["ab", "c", "def"]
@@ -49,20 +74,22 @@ splitBy isSep src
 -- >>> quoteStr "ab\"c"
 -- "\"ab\\\"c\""
 quoteStr ∷ Ascii → AsciiBuilder
-quoteStr str = A.toAsciiBuilder "\"" ⊕
-               go (A.toByteString str) (∅) ⊕
-               A.toAsciiBuilder "\""
+quoteStr str = cs ("\"" ∷ Ascii) ⊕
+               go (cs str) (∅)   ⊕
+               cs ("\"" ∷ Ascii)
     where
-      go ∷ BS.ByteString → AsciiBuilder → AsciiBuilder
+      go ∷ 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 "\\\"")
+                  | BS.null y
+                      → ab ⊕ b2ab x
+                  | otherwise
+                      → go (BS.tail y)
+                           (ab ⊕ b2ab x ⊕ cs ("\\\"" ∷ Ascii))
 
-      b2ab ∷ BS.ByteString → AsciiBuilder
-      b2ab = A.toAsciiBuilder ∘ A.unsafeFromByteString
+      b2ab ∷ ByteString → AsciiBuilder
+      b2ab = cs ∘ A.unsafeFromByteString
 
 -- |>>> parseWWWFormURLEncoded "aaa=bbb&ccc=ddd"
 -- [("aaa", "bbb"), ("ccc", "ddd")]
@@ -71,7 +98,7 @@ parseWWWFormURLEncoded src
     -- THINKME: We could gain some performance by using attoparsec
     -- here.
     | src ≡ ""  = []
-    | otherwise = do pairStr ← splitBy (\ c → c ≡ ';' ∨ c ≡ '&') (A.toString src)
+    | otherwise = do pairStr ← splitBy (\ c → c ≡ ';' ∨ c ≡ '&') (cs src)
                      let (key, value) = break (≡ '=') pairStr
                      return ( unescape key
                             , unescape $ case value of
@@ -80,20 +107,27 @@ parseWWWFormURLEncoded src
                             )
     where
       unescape ∷ String → ByteString
-      unescape = BS.pack ∘ unEscapeString ∘ map plusToSpace
+      unescape = BS.pack ∘ unEscapeString ∘ (plusToSpace <$>)
 
       plusToSpace ∷ Char → Char
       plusToSpace '+' = ' '
       plusToSpace c   = c
 
--- |>>> splitPathInfo "http://example.com/foo/bar"
+-- |>>> uriHost "http://example.com/foo/bar"
+-- "example.com"
+uriHost ∷ URI → Host
+{-# INLINE uriHost #-}
+uriHost = CI.mk ∘ cs ∘ uriRegName ∘ fromJust ∘ uriAuthority
+
+-- |>>> uriPathSegments "http://example.com/foo/bar"
 -- ["foo", "bar"]
-splitPathInfo ∷ URI → [ByteString]
-splitPathInfo uri
+uriPathSegments ∷ URI → Path
+uriPathSegments uri
     = let reqPathStr = uriPath uri
-          reqPath    = [unEscapeString x | x ← splitBy (≡ '/') reqPathStr, (¬) (null x)]
+          reqPath    = [ unEscapeString x
+                         | x ← splitBy (≡ '/') reqPathStr, (¬) (null x) ]
       in
-        map BS.pack reqPath
+        BS.pack <$> reqPath
 
 -- |>>> trim "  ab c d "
 -- "ab c d"
@@ -102,24 +136,34 @@ trim = reverse ∘ f ∘ reverse ∘ f
     where
       f = dropWhile isSpace
 
--- |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
+infixr 5 ⊲
+-- | (&#x22B2;) = ('<|')
+--
+-- U+22B2, NORMAL SUBGROUP OF
+(⊲) ∷ Sequence α a ⇒ a → α → α
+(⊲) = (<|)
 
--- |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
+infixl 5 ⊳
+-- | (&#x22B3;) = ('|>')
+--
+-- U+22B3, CONTAINS AS NORMAL SUBGROUP
+(⊳) ∷ Sequence α a ⇒ α → a → α
+(⊳) = (|>)
 
--- |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
-      liftPairs       = listE ∘ map liftPair
-      liftPair (k, v) = tupE [liftK k, liftV v]
+infixr 5 ⋈
+-- | (&#x22C8;) = ('><')
+--
+-- U+22C8, BOWTIE
+(⋈) ∷ Sequence α a ⇒ α → α → α
+(⋈) = (><)
+
+-- |Generalised @mapM@ from any 'Foldable' to 'Unfoldable'. Why isn't
+-- this in the @collections-api@?
+mapM ∷ (Foldable α a, Unfoldable β b, Functor m, Monad m)
+     ⇒ (a → m b) → α → m β
+{-# INLINE mapM #-}
+mapM = flip foldrM empty ∘ (flip ((<$>) ∘ flip insert) ∘)
+
+-- |Get the modification time of a given file.
+getLastModified ∷ FilePath → IO UTCTime
+getLastModified = (cs <$>) ∘ getModificationTime