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- /*
- MIT License http://www.opensource.org/licenses/mit-license.php
- Author Tobias Koppers @sokra
- */
- "use strict";
-
- const util = require("util");
-
- const TOMBSTONE = {};
- const UNDEFINED_MARKER = {};
-
- class StackedSetMap {
- constructor(parentStack) {
- this.stack = parentStack === undefined ? [] : parentStack.slice();
- this.map = new Map();
- this.stack.push(this.map);
- }
-
- add(item) {
- this.map.set(item, true);
- }
-
- set(item, value) {
- this.map.set(item, value === undefined ? UNDEFINED_MARKER : value);
- }
-
- delete(item) {
- if (this.stack.length > 1) {
- this.map.set(item, TOMBSTONE);
- } else {
- this.map.delete(item);
- }
- }
-
- has(item) {
- const topValue = this.map.get(item);
- if (topValue !== undefined) return topValue !== TOMBSTONE;
- if (this.stack.length > 1) {
- for (var i = this.stack.length - 2; i >= 0; i--) {
- const value = this.stack[i].get(item);
- if (value !== undefined) {
- this.map.set(item, value);
- return value !== TOMBSTONE;
- }
- }
- this.map.set(item, TOMBSTONE);
- }
- return false;
- }
-
- get(item) {
- const topValue = this.map.get(item);
- if (topValue !== undefined) {
- return topValue === TOMBSTONE || topValue === UNDEFINED_MARKER
- ? undefined
- : topValue;
- }
- if (this.stack.length > 1) {
- for (var i = this.stack.length - 2; i >= 0; i--) {
- const value = this.stack[i].get(item);
- if (value !== undefined) {
- this.map.set(item, value);
- return value === TOMBSTONE || value === UNDEFINED_MARKER
- ? undefined
- : value;
- }
- }
- this.map.set(item, TOMBSTONE);
- }
- return undefined;
- }
-
- _compress() {
- if (this.stack.length === 1) return;
- this.map = new Map();
- for (const data of this.stack) {
- for (const pair of data) {
- if (pair[1] === TOMBSTONE) {
- this.map.delete(pair[0]);
- } else {
- this.map.set(pair[0], pair[1]);
- }
- }
- }
- this.stack = [this.map];
- }
-
- asArray() {
- this._compress();
- return Array.from(this.map.entries(), pair => pair[0]);
- }
-
- asSet() {
- return new Set(this.asArray());
- }
-
- asPairArray() {
- this._compress();
- return Array.from(this.map.entries(), pair =>
- /** @type {[TODO, TODO]} */ (pair[1] === UNDEFINED_MARKER
- ? [pair[0], undefined]
- : pair)
- );
- }
-
- asMap() {
- return new Map(this.asPairArray());
- }
-
- get size() {
- this._compress();
- return this.map.size;
- }
-
- createChild() {
- return new StackedSetMap(this.stack);
- }
-
- get length() {
- throw new Error("This is no longer an Array");
- }
-
- set length(value) {
- throw new Error("This is no longer an Array");
- }
- }
-
- // TODO remove in webpack 5
- StackedSetMap.prototype.push = util.deprecate(
- /**
- * @deprecated
- * @this {StackedSetMap}
- * @param {any} item Item to add
- * @returns {void}
- */
- function(item) {
- this.add(item);
- },
- "This is no longer an Array: Use add instead."
- );
-
- module.exports = StackedSetMap;
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