WeakTupleMap.js
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/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
"use strict";
const isWeakKey = thing => typeof thing === "object" && thing !== null;
/**
* @template {any[]} T
* @template V
*/
class WeakTupleMap {
constructor() {
/** @private */
this.f = 0;
/** @private @type {any} */
this.v = undefined;
/** @private @type {Map<object, WeakTupleMap<T, V>> | undefined} */
this.m = undefined;
/** @private @type {WeakMap<object, WeakTupleMap<T, V>> | undefined} */
this.w = undefined;
}
/**
* @param {[...T, V]} args tuple
* @returns {void}
*/
set(...args) {
/** @type {WeakTupleMap<T, V>} */
let node = this;
for (let i = 0; i < args.length - 1; i++) {
node = node._get(args[i]);
}
node._setValue(args[args.length - 1]);
}
/**
* @param {T} args tuple
* @returns {boolean} true, if the tuple is in the Set
*/
has(...args) {
/** @type {WeakTupleMap<T, V>} */
let node = this;
for (let i = 0; i < args.length; i++) {
node = node._peek(args[i]);
if (node === undefined) return false;
}
return node._hasValue();
}
/**
* @param {T} args tuple
* @returns {V} the value
*/
get(...args) {
/** @type {WeakTupleMap<T, V>} */
let node = this;
for (let i = 0; i < args.length; i++) {
node = node._peek(args[i]);
if (node === undefined) return undefined;
}
return node._getValue();
}
/**
* @param {[...T, function(): V]} args tuple
* @returns {V} the value
*/
provide(...args) {
/** @type {WeakTupleMap<T, V>} */
let node = this;
for (let i = 0; i < args.length - 1; i++) {
node = node._get(args[i]);
}
if (node._hasValue()) return node._getValue();
const fn = args[args.length - 1];
const newValue = fn(...args.slice(0, -1));
node._setValue(newValue);
return newValue;
}
/**
* @param {T} args tuple
* @returns {void}
*/
delete(...args) {
/** @type {WeakTupleMap<T, V>} */
let node = this;
for (let i = 0; i < args.length; i++) {
node = node._peek(args[i]);
if (node === undefined) return;
}
node._deleteValue();
}
/**
* @returns {void}
*/
clear() {
this.f = 0;
this.v = undefined;
this.w = undefined;
this.m = undefined;
}
_getValue() {
return this.v;
}
_hasValue() {
return (this.f & 1) === 1;
}
_setValue(v) {
this.f |= 1;
this.v = v;
}
_deleteValue() {
this.f &= 6;
this.v = undefined;
}
_peek(thing) {
if (isWeakKey(thing)) {
if ((this.f & 4) !== 4) return undefined;
return this.w.get(thing);
} else {
if ((this.f & 2) !== 2) return undefined;
return this.m.get(thing);
}
}
_get(thing) {
if (isWeakKey(thing)) {
if ((this.f & 4) !== 4) {
const newMap = new WeakMap();
this.f |= 4;
const newNode = new WeakTupleMap();
(this.w = newMap).set(thing, newNode);
return newNode;
}
const entry = this.w.get(thing);
if (entry !== undefined) {
return entry;
}
const newNode = new WeakTupleMap();
this.w.set(thing, newNode);
return newNode;
} else {
if ((this.f & 2) !== 2) {
const newMap = new Map();
this.f |= 2;
const newNode = new WeakTupleMap();
(this.m = newMap).set(thing, newNode);
return newNode;
}
const entry = this.m.get(thing);
if (entry !== undefined) {
return entry;
}
const newNode = new WeakTupleMap();
this.m.set(thing, newNode);
return newNode;
}
}
}
module.exports = WeakTupleMap;