56 lines
1.6 KiB
TypeScript
56 lines
1.6 KiB
TypeScript
/**
|
|
* Gets the index associated with `key` in the backing array, if it is already present.
|
|
*/
|
|
export let get: (strarr: SetArray, key: string) => number | undefined;
|
|
|
|
/**
|
|
* Puts `key` into the backing array, if it is not already present. Returns
|
|
* the index of the `key` in the backing array.
|
|
*/
|
|
export let put: (strarr: SetArray, key: string) => number;
|
|
|
|
/**
|
|
* Pops the last added item out of the SetArray.
|
|
*/
|
|
export let pop: (strarr: SetArray) => void;
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
export class SetArray {
|
|
private declare _indexes: { [key: string]: number | undefined };
|
|
declare array: readonly string[];
|
|
|
|
constructor() {
|
|
this._indexes = { __proto__: null } as any;
|
|
this.array = [];
|
|
}
|
|
|
|
static {
|
|
get = (strarr, key) => strarr._indexes[key];
|
|
|
|
put = (strarr, key) => {
|
|
// The key may or may not be present. If it is present, it's a number.
|
|
const index = get(strarr, key);
|
|
if (index !== undefined) return index;
|
|
|
|
const { array, _indexes: indexes } = strarr;
|
|
|
|
return (indexes[key] = (array as string[]).push(key) - 1);
|
|
};
|
|
|
|
pop = (strarr) => {
|
|
const { array, _indexes: indexes } = strarr;
|
|
if (array.length === 0) return;
|
|
|
|
const last = (array as string[]).pop()!;
|
|
indexes[last] = undefined;
|
|
};
|
|
}
|
|
}
|