diff options
Diffstat (limited to 'src/lqueue.erl')
| -rw-r--r-- | src/lqueue.erl | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/src/lqueue.erl b/src/lqueue.erl index 0652061075..1abe4e0b82 100644 --- a/src/lqueue.erl +++ b/src/lqueue.erl @@ -21,7 +21,7 @@ %% is an O(1) operation, in contrast with queue:len/1 which is O(n). -export([new/0, is_empty/1, len/1, in/2, in_r/2, out/1, out_r/1, join/2, - foldl/3, foldr/3, from_list/1, to_list/1, peek/1, peek_r/1]). + foldl/3, foldr/3, from_list/1, drop/1, to_list/1, peek/1, peek_r/1]). -define(QUEUE, queue). @@ -32,6 +32,7 @@ -type result() :: 'empty' | {'value', value()}. -spec new() -> ?MODULE(). +-spec drop(?MODULE()) -> ?MODULE(). -spec is_empty(?MODULE()) -> boolean(). -spec len(?MODULE()) -> non_neg_integer(). -spec in(value(), ?MODULE()) -> ?MODULE(). @@ -48,6 +49,8 @@ new() -> {0, ?QUEUE:new()}. +drop({L, Q}) -> {L - 1, ?QUEUE:drop(Q)}. + is_empty({0, _Q}) -> true; is_empty(_) -> false. @@ -81,7 +84,8 @@ foldr(Fun, Init, Q) -> {{value, V}, Q1} -> foldr(Fun, Fun(V, Init), Q1) end. -len({L, _Q}) -> L. +len({L, _}) -> L. + peek({ 0, _Q}) -> empty; peek({_L, Q}) -> ?QUEUE:peek(Q). |