shelving/util/dispose.js

Toolkit for using data in JavaScript.

import { logError } from "./error.js";
import { isObject } from "./object.js";
/**
 * Temporary polyfill for `Symbol.dipose` value.
 * @todo Remove this once browsers support `Symbol.dispose`
 */
Symbol.dispose ??= Symbol("Symbol.dispose");
/** Safely dispose a disposable. */
export function dispose(value) {
    try {
        value[Symbol.dispose]();
    }
    catch (thrown) {
        logError(thrown);
    }
}
/** Is an unknown value a disposable object? */
export function isDisposable(v) {
    return isObject(v) && typeof v[Symbol.dispose] === "function";
}
/**
 * Version of `Map` that is disposable.
 * - If items are `Disposable` they are disposed when they're deleted from the map.
 * - Set itself is `Disposable` to delete (and dispose) all items when the map itself is disposed.
 */
export class DisposableMap extends Map {
    delete(key) {
        if (this.has(key)) {
            const value = this.get(key);
            super.delete(key);
            if (isDisposable(value))
                dispose(value);
            return true;
        }
        return false;
    }
    [Symbol.dispose]() {
        for (const key of this.keys())
            this.delete(key);
    }
}
/**
 * Version of `Set` that is disposable.
 * - If items are `Disposable` they are disposed when they're deleted from the set.
 * - Set itself is `Disposable` to delete (and dispose) all items when the set itself is disposed.
 */
export class DisposableSet extends Set {
    delete(item) {
        if (this.has(item)) {
            super.delete(item);
            if (isDisposable(item))
                dispose(item);
            return true;
        }
        return false;
    }
    [Symbol.dispose]() {
        for (const item of this)
            this.delete(item);
    }
}