Tests for Data.Time.RFC1123

[time-http.git] / Data / Time / HTTP / Common.hs

diff --git a/Data/Time/HTTP/Common.hs b/Data/Time/HTTP/Common.hs
index cf5412c28b093eca5844e8286cec529f78f4a6e8..f7c74c91e1326b5944ea06d5082c0415ac2f0044 100644 (file)
--- a/Data/Time/HTTP/Common.hs
+++ b/Data/Time/HTTP/Common.hs
@@ -15,11 +15,13 @@ module Data.Time.HTTP.Common
     , longMonthName
     , longMonthNameP
 
-    , show2
     , show4
+    , show2
+    , show2'
 
-    , read2
     , read4
+    , read2
+    , read2'
 
     , show4digitsTZ
     , read4digitsTZ
@@ -38,6 +40,7 @@ import Control.Monad
 import Data.Ascii (AsciiBuilder)
 import qualified Data.Ascii as A
 import Data.Attoparsec.Char8 as P
+import Data.Char
 import Data.Monoid.Unicode
 import Data.Fixed
 import Data.Time
@@ -211,6 +214,14 @@ show2 = A.unsafeFromBuilder ∘ go
            | i ≥ 0 ∧ i < 100 =                        BT.integral i
            | otherwise       = error ("show2: the integer i must satisfy 0 <= i < 100: " ⧺ show i)
 
+show2' ∷ Integral i ⇒ i → AsciiBuilder
+{-# INLINE show2' #-}
+show2' = A.unsafeFromBuilder ∘ go
+    where
+      go i | i ≥ 0 ∧ i < 10  = B.fromByteString " " ⊕ BT.digit    i
+           | i ≥ 0 ∧ i < 100 =                        BT.integral i
+           | otherwise       = error ("show2': the integer i must satisfy 0 <= i < 100: " ⧺ show i)
+
 read4 ∷ Num n ⇒ Parser n
 {-# INLINEABLE read4 #-}
 read4 = do n1 ← digit'
@@ -225,21 +236,18 @@ read2 = do n1 ← digit'
            n2 ← digit'
            return (n1 * 10 + n2)
 
-digit' ∷ Num n ⇒ Parser n
-digit' = fromC <$> P.digit
+read2' ∷ Num n ⇒ Parser n
+{-# INLINEABLE read2' #-}
+read2' = do n1 ← (char ' ' *> pure 0) <|> digit'
+            n2 ← digit'
+            return (n1 * 10 + n2)
 
-fromC ∷ Num n ⇒ Char → n
-fromC '0' = 0
-fromC '1' = 1
-fromC '2' = 2
-fromC '3' = 3
-fromC '4' = 4
-fromC '5' = 5
-fromC '6' = 6
-fromC '7' = 7
-fromC '8' = 8
-fromC '9' = 9
-fromC _   = undefined
+digit' ∷ Num n ⇒ Parser n
+{-# INLINE digit' #-}
+digit' = fromIntegral <$> fromC <$> P.digit
+    where
+      {-# INLINE fromC #-}
+      fromC c = ord c - ord '0'
 
 show4digitsTZ ∷ TimeZone → AsciiBuilder
 show4digitsTZ tz