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authorGravatar Joey Hess <joey@kitenet.net>2013-09-27 19:52:36 -0400
committerGravatar Joey Hess <joey@kitenet.net>2013-09-27 19:52:36 -0400
commitcbf810a421901e76ee2d3e18592fb4d39de851a6 (patch)
tree222eb2bedae5ddd3703d611a5b31a5b396dca75f /Utility/Data.hs
parent7d1b396cc863fb93869b7358dcfe1908985a21b8 (diff)
clean up some ugly code
Diffstat (limited to 'Utility/Data.hs')
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+{- 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