From 41b53ca04b6d52457f331930e8fea68416498882 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ra=C3=BAl=20Benencia?= <rul@kalgan.cc>
Date: Thu, 5 Sep 2013 19:36:33 -0300
Subject: New project tree structure

---
 Codec/Text/Rfc1342.hs | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 Codec/Text/Rfc1342.hs

(limited to 'Codec/Text')

diff --git a/Codec/Text/Rfc1342.hs b/Codec/Text/Rfc1342.hs
new file mode 100644
index 0000000..f6d8fe2
--- /dev/null
+++ b/Codec/Text/Rfc1342.hs
@@ -0,0 +1,57 @@
+{- A simple RFC1342 decoder.
+ -
+ - Copyright 2013 Raúl Benencia <rul@kalgan.cc>
+ -
+ - Licensed under the GNU GPL version 3 or higher
+ -
+ -}
+module Codec.Text.Rfc1342 (decodeField) where
+
+import qualified Codec.Binary.Base64 as B64
+import qualified Codec.Binary.QuotedPrintable as QP
+
+import Data.Char (toLower, isSpace, chr)
+import Data.List(isPrefixOf)
+import Data.Word (Word8)
+
+import Data.Encoding(decodeString)
+
+-- Encoding imports. If you want to support more encodings, just add'em here.
+import Data.Encoding.UTF8
+import Data.Encoding.ISO88591
+import Data.Encoding.ISO88592
+import Data.Encoding.ISO88598
+import Data.Encoding.ISO88599
+
+decodeField :: String -> String
+decodeField ('=':'?':cs) = decodeWithCharset dec rest
+  where (encoding, rest) = span (\c -> c /= '?') cs
+        dec = case (map toLower encoding) of
+          "utf-8"      -> decodeString UTF8
+          "iso-8859-1" -> decodeString ISO88591
+          "iso-8859-2" -> decodeString ISO88592
+          "iso-8859-8" -> decodeString ISO88598
+          "iso-8859-9" -> decodeString ISO88599
+          _            -> id
+decodeField []           = []
+decodeField (c:cs)       = c:decodeField cs
+
+decodeWithCharset dec [] = []
+decodeWithCharset dec ('?':c:'?':cs) | toLower c == 'b' = dataDecodeWith B64.decode
+                                     | toLower c == 'q' = dataDecodeWith QP.decode
+                                     | otherwise        = cs
+  where (encoded, rest') = span  (\c -> c /= '?') cs
+        rest = if "?=" `isPrefixOf` rest'
+               then drop 2 rest'
+               else rest'
+        dataDecodeWith datadec = (_2spc . dec . unwrap . datadec $ encoded) ++ decodeField rest -- ++ (decodeField $ dropWhile isSpace rest)
+
+unwrap :: Maybe [Word8] -> String
+unwrap Nothing    = []
+unwrap (Just str) = bytesToString str
+
+bytesToString :: [Word8] -> String
+bytesToString = map (chr . fromIntegral)
+
+-- Sometimes an underscore represents the SPACE character
+_2spc = map (\x -> if x == '_' then ' ' else x)
\ No newline at end of file
-- 
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