Resurrection from bitrot

[Rakka.git] / Rakka / Utils.hs

diff --git a/Rakka/Utils.hs b/Rakka/Utils.hs
index 15bc6f4043f5a87f149cd09a5147c4cb4cb5be7c..3148c6bf108906112b39ebb81f63132ae8baa158 100644 (file)
--- a/Rakka/Utils.hs
+++ b/Rakka/Utils.hs
@@ -1,3 +1,9 @@
+{-# LANGUAGE
+    Arrows
+  , OverloadedStrings
+  , TypeOperators
+  , UnicodeSyntax
+  #-}
 module Rakka.Utils
     ( yesOrNo
     , trueOrFalse
@@ -10,35 +16,34 @@ module Rakka.Utils
     , mkQueryString
     )
     where
-
 import qualified Codec.Binary.UTF8.String as UTF8
 import           Control.Arrow
 import           Control.Arrow.ArrowList
 import qualified Data.ByteString.Lazy as Lazy (ByteString)
 import qualified Data.ByteString.Lazy.Char8 as L8 hiding (ByteString)
+import Data.Monoid.Unicode
+import Data.String
 import           Magic
 import           Network.HTTP.Lucu
 import           Network.URI
+import Prelude.Unicode
 import           System.IO.Unsafe
 
-
-yesOrNo :: Bool -> String
+yesOrNo ∷ Bool → String
 yesOrNo True  = "yes"
 yesOrNo False = "no"
 
-
-trueOrFalse :: Bool -> String
+trueOrFalse ∷ Bool → String
 trueOrFalse True  = "true"
 trueOrFalse False = "false"
 
-
-parseYesOrNo :: ArrowChoice a => a String Bool
-parseYesOrNo 
-    = proc str -> do case str of
-                       "yes" -> returnA -< True
-                       "no"  -> returnA -< False
-                       _     -> returnA -< error ("Expected yes or no: " ++ str)
-
+parseYesOrNo ∷ (Eq s, Show s, IsString s, ArrowChoice (⇝)) ⇒ s ⇝ Bool
+parseYesOrNo
+    = proc str →
+      case str of
+        _ | str ≡ "yes" → returnA ⤙ True
+          | str ≡ "no"  → returnA ⤙ False
+          | otherwise   → returnA ⤙ error ("Expected yes or no: " ⊕ show str)
 
 maybeA :: (ArrowList a, ArrowChoice a) => a b c -> a b (Maybe c)
 maybeA a = listA a