State changes on vt switch.

1 files changed, 20 insertions, 0 deletions

diff --git a/Presence/ByteStringOperators.hs b/Presence/ByteStringOperators.hs
index 26b64bcf..2815f05a 100644
--- a/Presence/ByteStringOperators.hs
+++ b/Presence/ByteStringOperators.hs
@@ -3,6 +3,11 @@ module ByteStringOperators where
 import qualified Data.ByteString as S (ByteString)
 import Data.ByteString.Lazy.Char8 as L 
 
+-- These two were imported to provide an NFData instance.
+import qualified Data.ByteString.Lazy.Internal as L (ByteString(..))
+import Control.DeepSeq
+
+
 (<++>) :: ByteString -> ByteString -> ByteString
 (<++.>) :: ByteString -> S.ByteString -> ByteString
 (<.++>) :: S.ByteString -> ByteString -> ByteString
@@ -16,5 +21,20 @@ infixr 5 <.++>
 infixr 5 <++>
 infixr 5 <++.>
 
+Nothing <?++> b = b
+Just a  <?++> b = a <++> b
+infixr 5 <?++>
+
+a <++?> Nothing = a
+a <++?> Just b  = a <++> b
+infixr 5 <++?>
+
 bshow :: Show a => a -> ByteString
 bshow = L.pack . show
+
+
+instance NFData L.ByteString where
+    rnf L.Empty       = ()
+    rnf (L.Chunk _ b) = rnf b
+
+