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Diffstat (limited to 'Utility/Data.hs')
-rw-r--r-- | Utility/Data.hs | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/Utility/Data.hs b/Utility/Data.hs new file mode 100644 index 0000000..27c0a82 --- /dev/null +++ b/Utility/Data.hs @@ -0,0 +1,19 @@ +{- utilities for simple data types + - + - Copyright 2013 Joey Hess <id@joeyh.name> + - + - License: BSD-2-clause + -} + +{-# OPTIONS_GHC -fno-warn-tabs #-} + +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 |