copied from git-annex

1 files changed, 17 insertions, 0 deletions

diff --git a/Utility/Data.hs b/Utility/Data.hs
new file mode 100644
index 0000000..3592582
--- /dev/null
+++ b/Utility/Data.hs
@@ -0,0 +1,17 @@
+{- utilities for simple data types
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Utility.Data where
+
+{- First item in the list that is not Nothing. -}
+firstJust :: Eq a => [Maybe a] -> Maybe a
+firstJust ms = case dropWhile (== Nothing) ms of
+	[] -> Nothing
+	(md:_) -> md
+
+eitherToMaybe :: Either a b -> Maybe b
+eitherToMaybe = either (const Nothing) Just