aboutsummaryrefslogtreecommitdiff
path: root/Utility/Data.hs
blob: 27c0a824c267600af52bbc29315edac0475b80a3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
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