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| author | j.uhlig <[email protected]> | 2018-03-19 16:32:41 +0100 |
|---|---|---|
| committer | j.uhlig <[email protected]> | 2018-03-19 16:32:41 +0100 |
| commit | 35ae53a6c37c670fdfe1e3ea8dc118e443febbf3 (patch) | |
| tree | 417780efe36c3a957f95b184e84a5d873371c29f /lib/stdlib/src | |
| parent | df7d961bfd648e88b50eb3762af39a3cd985bc11 (diff) | |
| download | otp-35ae53a6c37c670fdfe1e3ea8dc118e443febbf3.tar.gz otp-35ae53a6c37c670fdfe1e3ea8dc118e443febbf3.tar.bz2 otp-35ae53a6c37c670fdfe1e3ea8dc118e443febbf3.zip | |
is_empty/1 for sets
Diffstat (limited to 'lib/stdlib/src')
| -rw-r--r-- | lib/stdlib/src/sets.erl | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/lib/stdlib/src/sets.erl b/lib/stdlib/src/sets.erl index c65a13b22e..ac0fc80526 100644 --- a/lib/stdlib/src/sets.erl +++ b/lib/stdlib/src/sets.erl @@ -37,7 +37,7 @@ -module(sets). %% Standard interface. --export([new/0,is_set/1,size/1,to_list/1,from_list/1]). +-export([new/0,is_set/1,size/1,is_empty/1,to_list/1,from_list/1]). -export([is_element/2,add_element/2,del_element/2]). -export([union/2,union/1,intersection/2,intersection/1]). -export([is_disjoint/2]). @@ -96,6 +96,12 @@ is_set(_) -> false. Set :: set(). size(S) -> S#set.size. +%% is_empty(Set) -> boolean(). +%% Return 'true' if Set is an empty set, otherwise 'false'. +-spec is_empty(Set) -> boolean() when + Set :: set(). +is_empty(S) -> S#set.size=:=0. + %% to_list(Set) -> [Elem]. %% Return the elements in Set as a list. -spec to_list(Set) -> List when |