Add support for the Text and ByteString types.

Data/Convertible/Instances.hs

@@ -36,4 +36,5 @@ module Data.Convertible.Instances(
 import Data.Convertible.Instances.C()
 import Data.Convertible.Instances.Map()
 import Data.Convertible.Instances.Num()
+import Data.Convertible.Instances.Text()
 import Data.Convertible.Instances.Time()

Data/Convertible/Instances/Text.hs

@@ -0,0 +1,74 @@
+{- |
+   Module     : Data.Convertible.Instances.Text
+   Copyright  : Copyright (C) 2011 MailRank, Inc.
+   License    : LGPL
+
+   Maintainer : John Goerzen <jgoerzen@complete.org>
+   Stability  : provisional
+   Portability: portable
+
+Text instances for Convertible.
+
+Copyright (C) 2011 MailRank, Inc. <bos@mailrank.com>
+
+All rights reserved.
+
+For license and copyright information, see the file COPYRIGHT
+
+These instances perform conversion between text-like types such as
+Text, ByteString, and the like.
+
+The instances do /not/ include conversions between ByteString and
+Text or String, since such conversions cannot safely be performed
+without knowing the encoding of the ByteString.
+-}
+
+module Data.Convertible.Instances.Text()
+where
+
+import Data.Convertible.Base
+import qualified Data.Text as TS
+import qualified Data.Text.Lazy as TL
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as BL
+import Data.Word (Word8)
+
+-- Text
+
+instance Convertible [Char] TS.Text where
+    safeConvert = Right . TS.pack
+
+instance Convertible TS.Text [Char] where
+    safeConvert = Right . TS.unpack
+
+instance Convertible [Char] TL.Text where
+    safeConvert = Right . TL.pack
+
+instance Convertible TL.Text [Char] where
+    safeConvert = Right . TL.unpack
+
+instance Convertible TS.Text TL.Text where
+    safeConvert = Right . TL.fromStrict
+
+instance Convertible TL.Text TS.Text where
+    safeConvert = Right . TL.toStrict
+
+-- ByteString
+
+instance Convertible [Word8] BS.ByteString where
+    safeConvert = Right . BS.pack
+
+instance Convertible BS.ByteString [Word8] where
+    safeConvert = Right . BS.unpack
+
+instance Convertible [Word8] BL.ByteString where
+    safeConvert = Right . BL.pack
+
+instance Convertible BL.ByteString [Word8] where
+    safeConvert = Right . BL.unpack
+
+instance Convertible BS.ByteString BL.ByteString where
+    safeConvert = Right . BL.fromChunks . (:[])
+
+instance Convertible BL.ByteString BS.ByteString where
+    safeConvert = Right . BS.concat . BL.toChunks

convertible.cabal

@@ -59,7 +59,7 @@ library
       Build-Depends: time<1.1.3
   else
     Build-Depends: base<3
-  Build-Depends: mtl
+  Build-Depends: mtl, text
 
   GHC-Options: -O2 -Wall -fno-warn-orphans
 
@@ -70,6 +70,7 @@ library
                    Data.Convertible.Instances.C,
                    Data.Convertible.Instances.Map,
                    Data.Convertible.Instances.Num,
+                   Data.Convertible.Instances.Text,
                    Data.Convertible.Instances.Time
 
   --Other-Modules: Database.HDBC.Utils