summaryrefslogtreecommitdiff
path: root/src/Utility/Data.hs
diff options
context:
space:
mode:
authorJoey Hess <joeyh@debian.org>2014-07-09 22:11:31 -0400
committerJoey Hess <joeyh@debian.org>2014-07-09 22:11:31 -0400
commit82da31b3e0e9acdfbca4c48eb12ab1f28515ba10 (patch)
tree0a3e0c6e134680e35665364b2cd6895863bcc990 /src/Utility/Data.hs
propellor (0.8.1) unstable; urgency=medium
* Run apt-get update in initial bootstrap. * --list-fields now includes a table of fields that are not currently set, but would be used if they got set. * Remove .gitignore from cabal file list, to avoid build failure on Debian. Closes: #754334 # imported from the archive
Diffstat (limited to 'src/Utility/Data.hs')
-rw-r--r--src/Utility/Data.hs17
1 files changed, 17 insertions, 0 deletions
diff --git a/src/Utility/Data.hs b/src/Utility/Data.hs
new file mode 100644
index 00000000..2df12b36
--- /dev/null
+++ b/src/Utility/Data.hs
@@ -0,0 +1,17 @@
+{- utilities for simple data types
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - License: BSD-2-clause
+ -}
+
+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