blob: 500eac0d39bcaa82a955166468bb5893210b6d0f [file] [log] [blame]
/*
* Copyright (C) 2018 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
class Multimap
{
constructor(items = [])
{
this._map = new Map;
for (let [key, value] of items)
this.add(key, value);
}
// Public
has(key, value)
{
let valueSet = this._map.get(key);
if (!valueSet)
return false;
return value === undefined || valueSet.has(value);
}
get(key)
{
return this._map.get(key);
}
add(key, value)
{
let valueSet = this._map.get(key);
if (!valueSet) {
valueSet = new Set;
this._map.set(key, valueSet);
}
valueSet.add(value);
return this;
}
delete(key, value)
{
// Allow an entire key to be removed by not passing a value.
if (arguments.length === 1)
return this._map.delete(key);
let valueSet = this._map.get(key);
if (!valueSet)
return false;
let deleted = valueSet.delete(value);
if (!valueSet.size)
this._map.delete(key);
return deleted;
}
clear()
{
this._map.clear();
}
keys()
{
return this._map.keys();
}
*values()
{
for (let valueSet of this._map.values()) {
for (let value of valueSet)
yield value;
}
}
sets()
{
return this._map.entries();
}
*[Symbol.iterator]()
{
for (let [key, valueSet] of this._map) {
for (let value of valueSet)
yield [key, value];
}
}
copy()
{
return new Multimap(this.toJSON());
}
toJSON()
{
return Array.from(this);
}
}