New module: Network.HTTP.Lucu.MIMEType.TH

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

diff --git a/Network/HTTP/Lucu/Utils.hs b/Network/HTTP/Lucu/Utils.hs
index 3d38b8b3aec36c9dff990cb4c7e66d05995ad27e..5cee03a56f6262c7d40ab1fe7059a566236cda73 100644 (file)
--- a/Network/HTTP/Lucu/Utils.hs
+++ b/Network/HTTP/Lucu/Utils.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE
     OverloadedStrings
+  , TemplateHaskell
   , UnicodeSyntax
   #-}
 -- |Utility functions used internally in the Lucu httpd. These
@@ -10,23 +11,34 @@ module Network.HTTP.Lucu.Utils
     , parseWWWFormURLEncoded
     , splitPathInfo
     , show3
+    , trim
+    , liftCIAscii
+    , liftText
+    , liftMap
     )
     where
 import Blaze.ByteString.Builder.ByteString as B
 import Blaze.Text.Int as BT
 import Control.Monad
-import Data.Ascii (Ascii, AsciiBuilder)
+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 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 (== ':') "ab:c:def"
+-- ["ab", "c", "def"]
 splitBy ∷ (a → Bool) → [a] → [[a]]
 {-# INLINEABLE splitBy #-}
 splitBy isSep src
@@ -34,11 +46,11 @@ splitBy isSep src
         (last , []       ) → [last]
         (first, _sep:rest) → first : splitBy isSep rest
 
--- |> quoteStr "abc"
---  > ==> "\"abc\""
+-- |>>> quoteStr "abc"
+-- "\"abc\""
 --
---  > quoteStr "ab\"c"
---  > ==> "\"ab\\\"c\""
+-- >>> quoteStr "ab\"c"
+-- "\"ab\\\"c\""
 quoteStr ∷ Ascii → AsciiBuilder
 quoteStr str = A.toAsciiBuilder "\"" ⊕
                go (A.toByteString str) (∅) ⊕
@@ -55,8 +67,8 @@ quoteStr str = A.toAsciiBuilder "\"" ⊕
       b2ab ∷ BS.ByteString → AsciiBuilder
       b2ab = A.toAsciiBuilder ∘ A.unsafeFromByteString
 
--- |> parseWWWFormURLEncoded "aaa=bbb&ccc=ddd"
---  > ==> [("aaa", "bbb"), ("ccc", "ddd")]
+-- |>>> parseWWWFormURLEncoded "aaa=bbb&ccc=ddd"
+-- [("aaa", "bbb"), ("ccc", "ddd")]
 parseWWWFormURLEncoded ∷ Ascii → [(ByteString, ByteString)]
 parseWWWFormURLEncoded src
     -- THINKME: We could gain some performance by using attoparsec
@@ -77,8 +89,8 @@ parseWWWFormURLEncoded src
       plusToSpace '+' = ' '
       plusToSpace c   = c
 
--- |> splitPathInfo "http://example.com/foo/bar"
---  > ==> ["foo", "bar"]
+-- |>>> splitPathInfo "http://example.com/foo/bar"
+-- ["foo", "bar"]
 splitPathInfo ∷ URI → [ByteString]
 splitPathInfo uri
     = let reqPathStr = uriPath uri
@@ -86,8 +98,8 @@ splitPathInfo uri
       in
         map BS.pack reqPath
 
--- |> show3 5
---  > ==> "005"
+-- |>>> show3 5
+-- "005"
 show3 ∷ Integral n ⇒ n → AsciiBuilder
 {-# INLINEABLE show3 #-}
 show3 = A.unsafeFromBuilder ∘ go
@@ -98,3 +110,32 @@ show3 = A.unsafeFromBuilder ∘ go
            | otherwise        = error ("show3: the integer i must satisfy 0 <= i < 1000: " ⧺ show i)
 -- FIXME: Drop this function as soon as possible, to eliminate the
 -- dependency on blaze-textual.
+
+-- |>>> trim "  ab c d "
+-- "ab c d"
+trim ∷ String → String
+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
+
+-- |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
+
+-- |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]