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| author | Joey Hess <joey@kitenet.net> | 2014-03-29 23:10:52 -0400 |
|---|---|---|
| committer | Joey Hess <joey@kitenet.net> | 2014-03-29 23:16:43 -0400 |
| commit | d9af8bac5eb7836a3c90e37e870fd73d30b841fd (patch) | |
| tree | 40443efd384415172cf393571fe3f1651ea57423 /Utility/Data.hs | |
initial check-in
too young to have a name
Diffstat (limited to 'Utility/Data.hs')
| -rw-r--r-- | Utility/Data.hs | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/Utility/Data.hs b/Utility/Data.hs new file mode 100644 index 00000000..35925829 --- /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 |
