aboutsummaryrefslogtreecommitdiffstats
path: root/lib/stdlib/src/queue.erl
diff options
context:
space:
mode:
Diffstat (limited to 'lib/stdlib/src/queue.erl')
-rw-r--r--lib/stdlib/src/queue.erl75
1 files changed, 38 insertions, 37 deletions
diff --git a/lib/stdlib/src/queue.erl b/lib/stdlib/src/queue.erl
index 4bbf5de8a5..472d503b99 100644
--- a/lib/stdlib/src/queue.erl
+++ b/lib/stdlib/src/queue.erl
@@ -1,7 +1,7 @@
%%
%% %CopyrightBegin%
%%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2014. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
@@ -32,6 +32,8 @@
-export([cons/2,head/1,tail/1,
snoc/2,last/1,daeh/1,init/1,liat/1,lait/1]).
+-export_type([queue/0, queue/1]).
+
%%--------------------------------------------------------------------------
%% Efficient implementation of double ended fifo queues
%%
@@ -44,10 +46,9 @@
%% that is; the RearList is reversed.
%%
-%% A declaration equivalent to the following is currently hard-coded
-%% in erl_types.erl
-%%
-%% -opaque queue() :: {list(), list()}.
+-opaque queue(Item) :: {list(Item), list(Item)}.
+
+-opaque queue() :: queue(_).
%% Creation, inspection and conversion
@@ -79,7 +80,7 @@ len(Q) ->
erlang:error(badarg, [Q]).
%% O(len(Q))
--spec to_list(Q :: queue()) -> list().
+-spec to_list(Q :: queue(Item)) -> list(Item).
to_list({In,Out}) when is_list(In), is_list(Out) ->
Out++lists:reverse(In, []);
to_list(Q) ->
@@ -88,7 +89,7 @@ to_list(Q) ->
%% Create queue from list
%%
%% O(length(L))
--spec from_list(L :: list()) -> queue().
+-spec from_list(L :: list(Item)) -> queue(Item).
from_list(L) when is_list(L) ->
f2r(L);
from_list(L) ->
@@ -97,7 +98,7 @@ from_list(L) ->
%% Return true or false depending on if element is in queue
%%
%% O(length(Q)) worst case
--spec member(Item :: term(), Q :: queue()) -> boolean().
+-spec member(Item, Q :: queue(Item)) -> boolean().
member(X, {R,F}) when is_list(R), is_list(F) ->
lists:member(X, R) orelse lists:member(X, F);
member(X, Q) ->
@@ -110,7 +111,7 @@ member(X, Q) ->
%% Put at least one element in each list, if it is cheap
%%
%% O(1)
--spec in(Item :: term(), Q1 :: queue()) -> Q2 :: queue().
+-spec in(Item, Q1 :: queue(Item)) -> Q2 :: queue(Item).
in(X, {[_]=In,[]}) ->
{[X], In};
in(X, {In,Out}) when is_list(In), is_list(Out) ->
@@ -122,7 +123,7 @@ in(X, Q) ->
%% Put at least one element in each list, if it is cheap
%%
%% O(1)
--spec in_r(Item :: term(), Q1 :: queue()) -> Q2 :: queue().
+-spec in_r(Item, Q1 :: queue(Item)) -> Q2 :: queue(Item).
in_r(X, {[],[_]=F}) ->
{F,[X]};
in_r(X, {R,F}) when is_list(R), is_list(F) ->
@@ -133,9 +134,9 @@ in_r(X, Q) ->
%% Take from head/front
%%
%% O(1) amortized, O(len(Q)) worst case
--spec out(Q1 :: queue()) ->
- {{value, Item :: term()}, Q2 :: queue()} |
- {empty, Q1 :: queue()}.
+-spec out(Q1 :: queue(Item)) ->
+ {{value, Item}, Q2 :: queue(Item)} |
+ {empty, Q1 :: queue(Item)}.
out({[],[]}=Q) ->
{empty,Q};
out({[V],[]}) ->
@@ -153,9 +154,9 @@ out(Q) ->
%% Take from tail/rear
%%
%% O(1) amortized, O(len(Q)) worst case
--spec out_r(Q1 :: queue()) ->
- {{value, Item :: term()}, Q2 :: queue()} |
- {empty, Q1 :: queue()}.
+-spec out_r(Q1 :: queue(Item)) ->
+ {{value, Item}, Q2 :: queue(Item)} |
+ {empty, Q1 :: queue(Item)}.
out_r({[],[]}=Q) ->
{empty,Q};
out_r({[],[V]}) ->
@@ -176,7 +177,7 @@ out_r(Q) ->
%% Return the first element in the queue
%%
%% O(1) since the queue is supposed to be well formed
--spec get(Q :: queue()) -> Item :: term().
+-spec get(Q :: queue(Item)) -> Item.
get({[],[]}=Q) ->
erlang:error(empty, [Q]);
get({R,F}) when is_list(R), is_list(F) ->
@@ -195,7 +196,7 @@ get([_|R], []) -> % malformed queue -> O(len(Q))
%% Return the last element in the queue
%%
%% O(1) since the queue is supposed to be well formed
--spec get_r(Q :: queue()) -> Item :: term().
+-spec get_r(Q :: queue(Item)) -> Item.
get_r({[],[]}=Q) ->
erlang:error(empty, [Q]);
get_r({[H|_],F}) when is_list(F) ->
@@ -210,7 +211,7 @@ get_r(Q) ->
%% Return the first element in the queue
%%
%% O(1) since the queue is supposed to be well formed
--spec peek(Q :: queue()) -> empty | {value,Item :: term()}.
+-spec peek(Q :: queue(Item)) -> empty | {value, Item}.
peek({[],[]}) ->
empty;
peek({R,[H|_]}) when is_list(R) ->
@@ -225,7 +226,7 @@ peek(Q) ->
%% Return the last element in the queue
%%
%% O(1) since the queue is supposed to be well formed
--spec peek_r(Q :: queue()) -> empty | {value,Item :: term()}.
+-spec peek_r(Q :: queue(Item)) -> empty | {value, Item}.
peek_r({[],[]}) ->
empty;
peek_r({[H|_],F}) when is_list(F) ->
@@ -240,7 +241,7 @@ peek_r(Q) ->
%% Remove the first element and return resulting queue
%%
%% O(1) amortized
--spec drop(Q1 :: queue()) -> Q2 :: queue().
+-spec drop(Q1 :: queue(Item)) -> Q2 :: queue(Item).
drop({[],[]}=Q) ->
erlang:error(empty, [Q]);
drop({[_],[]}) ->
@@ -258,7 +259,7 @@ drop(Q) ->
%% Remove the last element and return resulting queue
%%
%% O(1) amortized
--spec drop_r(Q1 :: queue()) -> Q2 :: queue().
+-spec drop_r(Q1 :: queue(Item)) -> Q2 :: queue(Item).
drop_r({[],[]}=Q) ->
erlang:error(empty, [Q]);
drop_r({[],[_]}) ->
@@ -279,7 +280,7 @@ drop_r(Q) ->
%% Return reversed queue
%%
%% O(1)
--spec reverse(Q1 :: queue()) -> Q2 :: queue().
+-spec reverse(Q1 :: queue(Item)) -> Q2 :: queue(Item).
reverse({R,F}) when is_list(R), is_list(F) ->
{F,R};
reverse(Q) ->
@@ -289,7 +290,7 @@ reverse(Q) ->
%%
%% Q2 empty: O(1)
%% else: O(len(Q1))
--spec join(Q1 :: queue(), Q2 :: queue()) -> Q3 :: queue().
+-spec join(Q1 :: queue(Item), Q2 :: queue(Item)) -> Q3 :: queue(Item).
join({R,F}=Q, {[],[]}) when is_list(R), is_list(F) ->
Q;
join({[],[]}, {R,F}=Q) when is_list(R), is_list(F) ->
@@ -303,8 +304,8 @@ join(Q1, Q2) ->
%%
%% N = 0..len(Q)
%% O(max(N, len(Q)))
--spec split(N :: non_neg_integer(), Q1 :: queue()) ->
- {Q2 :: queue(),Q3 :: queue()}.
+-spec split(N :: non_neg_integer(), Q1 :: queue(Item)) ->
+ {Q2 :: queue(Item),Q3 :: queue(Item)}.
split(0, {R,F}=Q) when is_list(R), is_list(F) ->
{{[],[]},Q};
split(N, {R,F}=Q) when is_integer(N), N >= 1, is_list(R), is_list(F) ->
@@ -345,8 +346,8 @@ split_r1_to_f2(N, [X|R1], F1, R2, F2) ->
%%
%% Fun(_) -> List: O(length(List) * len(Q))
%% else: O(len(Q)
--spec filter(Fun, Q1 :: queue()) -> Q2 :: queue() when
- Fun :: fun((Item :: term()) -> boolean() | list()).
+-spec filter(Fun, Q1 :: queue(Item)) -> Q2 :: queue(Item) when
+ Fun :: fun((Item) -> boolean() | list(Item)).
filter(Fun, {R0,F0}) when is_function(Fun, 1), is_list(R0), is_list(F0) ->
F = filter_f(Fun, F0),
R = filter_r(Fun, R0),
@@ -422,7 +423,7 @@ filter_r(Fun, [X|R0]) ->
%% Cons to head
%%
--spec cons(Item :: term(), Q1 :: queue()) -> Q2 :: queue().
+-spec cons(Item, Q1 :: queue(Item)) -> Q2 :: queue(Item).
cons(X, Q) ->
in_r(X, Q).
@@ -431,7 +432,7 @@ cons(X, Q) ->
%% Return the first element in the queue
%%
%% O(1) since the queue is supposed to be well formed
--spec head(Q :: queue()) -> Item :: term().
+-spec head(Q :: queue(Item)) -> Item.
head({[],[]}=Q) ->
erlang:error(empty, [Q]);
head({R,F}) when is_list(R), is_list(F) ->
@@ -441,7 +442,7 @@ head(Q) ->
%% Remove head element and return resulting queue
%%
--spec tail(Q1 :: queue()) -> Q2 :: queue().
+-spec tail(Q1 :: queue(Item)) -> Q2 :: queue(Item).
tail(Q) ->
drop(Q).
@@ -449,22 +450,22 @@ tail(Q) ->
%% Cons to tail
%%
--spec snoc(Q1 :: queue(), Item :: term()) -> Q2 :: queue().
+-spec snoc(Q1 :: queue(Item), Item) -> Q2 :: queue(Item).
snoc(Q, X) ->
in(X, Q).
%% Return last element
--spec daeh(Q :: queue()) -> Item :: term().
+-spec daeh(Q :: queue(Item)) -> Item.
daeh(Q) -> get_r(Q).
--spec last(Q :: queue()) -> Item :: term().
+-spec last(Q :: queue(Item)) -> Item.
last(Q) -> get_r(Q).
%% Remove last element and return resulting queue
--spec liat(Q1 :: queue()) -> Q2 :: queue().
+-spec liat(Q1 :: queue(Item)) -> Q2 :: queue(Item).
liat(Q) -> drop_r(Q).
--spec lait(Q1 :: queue()) -> Q2 :: queue().
+-spec lait(Q1 :: queue(Item)) -> Q2 :: queue(Item).
lait(Q) -> drop_r(Q). %% Oops, mis-spelled 'tail' reversed. Forget this one.
--spec init(Q1 :: queue()) -> Q2 :: queue().
+-spec init(Q1 :: queue(Item)) -> Q2 :: queue(Item).
init(Q) -> drop_r(Q).
%%--------------------------------------------------------------------------
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-01 13:41:07 +0000