From 8c24464a4bd0a486cd0ddf846d3b5a323a7aaa9a Mon Sep 17 00:00:00 2001 From: Joris Date: Sun, 4 Oct 2015 20:48:32 +0200 Subject: Using incomes to compute a fair computation to designate the payer --- src/client/Utils/Maybe.elm | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) (limited to 'src/client/Utils/Maybe.elm') diff --git a/src/client/Utils/Maybe.elm b/src/client/Utils/Maybe.elm index 507d9a4..d954ae0 100644 --- a/src/client/Utils/Maybe.elm +++ b/src/client/Utils/Maybe.elm @@ -1,9 +1,27 @@ module Utils.Maybe ( isJust + , catMaybes + , maybeToList ) where isJust : Maybe a -> Bool isJust maybe = case maybe of - Just _ -> True + Just _ -> True Nothing -> False + +catMaybes : List (Maybe a) -> List a +catMaybes = + List.foldr + (\mb xs -> + case mb of + Just x -> x :: xs + Nothing -> xs + ) + [] + +maybeToList : Maybe a -> List a +maybeToList mb = + case mb of + Just a -> [a] + Nothing -> [] -- cgit v1.2.3