devsite/node_modules/@jridgewell/set-array/dist/set-array.umd.js
2024-07-07 18:49:38 -07:00

84 lines
2.7 KiB
JavaScript

(function (global, factory) {
typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
typeof define === 'function' && define.amd ? define(['exports'], factory) :
(global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory(global.setArray = {}));
})(this, (function (exports) { 'use strict';
/**
* SetArray acts like a `Set` (allowing only one occurrence of a string `key`), but provides the
* index of the `key` in the backing array.
*
* This is designed to allow synchronizing a second array with the contents of the backing array,
* like how in a sourcemap `sourcesContent[i]` is the source content associated with `source[i]`,
* and there are never duplicates.
*/
class SetArray {
constructor() {
this._indexes = { __proto__: null };
this.array = [];
}
}
/**
* Typescript doesn't allow friend access to private fields, so this just casts the set into a type
* with public access modifiers.
*/
function cast(set) {
return set;
}
/**
* Gets the index associated with `key` in the backing array, if it is already present.
*/
function get(setarr, key) {
return cast(setarr)._indexes[key];
}
/**
* Puts `key` into the backing array, if it is not already present. Returns
* the index of the `key` in the backing array.
*/
function put(setarr, key) {
// The key may or may not be present. If it is present, it's a number.
const index = get(setarr, key);
if (index !== undefined)
return index;
const { array, _indexes: indexes } = cast(setarr);
const length = array.push(key);
return (indexes[key] = length - 1);
}
/**
* Pops the last added item out of the SetArray.
*/
function pop(setarr) {
const { array, _indexes: indexes } = cast(setarr);
if (array.length === 0)
return;
const last = array.pop();
indexes[last] = undefined;
}
/**
* Removes the key, if it exists in the set.
*/
function remove(setarr, key) {
const index = get(setarr, key);
if (index === undefined)
return;
const { array, _indexes: indexes } = cast(setarr);
for (let i = index + 1; i < array.length; i++) {
const k = array[i];
array[i - 1] = k;
indexes[k]--;
}
indexes[key] = undefined;
array.pop();
}
exports.SetArray = SetArray;
exports.get = get;
exports.pop = pop;
exports.put = put;
exports.remove = remove;
Object.defineProperty(exports, '__esModule', { value: true });
}));
//# sourceMappingURL=set-array.umd.js.map