From d9af8bac5eb7836a3c90e37e870fd73d30b841fd Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Sat, 29 Mar 2014 23:10:52 -0400 Subject: initial check-in too young to have a name --- Utility/Data.hs | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 Utility/Data.hs (limited to 'Utility/Data.hs') 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 + - + - 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 -- cgit v1.3-2-g0d8e