Add a suitable Show instance for TextEncoding (#4273)

[ghc-base.git] / GHC / IO / Encoding / Types.hs

diff --git a/GHC/IO/Encoding/Types.hs b/GHC/IO/Encoding/Types.hs
index 9be6c98..640ea88 100644 (file)
--- a/GHC/IO/Encoding/Types.hs
+++ b/GHC/IO/Encoding/Types.hs
@@ -22,6 +22,7 @@ module GHC.IO.Encoding.Types (
 
 import GHC.Base
 import GHC.Word
+import GHC.Show
 -- import GHC.IO
 import GHC.IO.Buffer
 
@@ -84,6 +85,13 @@ type TextEncoder state = BufferCodec CharBufElem Word8 state
 -- of bytes.  The 'TextEncoding' for UTF-8 is 'utf8'.
 data TextEncoding
   = forall dstate estate . TextEncoding  {
+        textEncodingName :: String,
+                   -- ^ a string that can be passed to 'mkTextEncoding' to
+                   -- create an equivalent 'TextEncoding'.
        mkTextDecoder :: IO (TextDecoder dstate),
        mkTextEncoder :: IO (TextEncoder estate)
   }
+
+instance Show TextEncoding where
+  -- | Returns the value of 'textEncodingName'
+  show te = textEncodingName te