@sussudio/base/common/lazy.mjs

Internal APIs for VS Code's utilities and user interface building blocks.

/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/
export class Lazy {
	executor;
	_didRun = false;
	_value;
	_error;
	constructor(executor) {
		this.executor = executor;
	}
	/**
	 * True if the lazy value has been resolved.
	 */
	hasValue() {
		return this._didRun;
	}
	/**
	 * Get the wrapped value.
	 *
	 * This will force evaluation of the lazy value if it has not been resolved yet. Lazy values are only
	 * resolved once. `getValue` will re-throw exceptions that are hit while resolving the value
	 */
	getValue() {
		if (!this._didRun) {
			try {
				this._value = this.executor();
			} catch (err) {
				this._error = err;
			} finally {
				this._didRun = true;
			}
		}
		if (this._error) {
			throw this._error;
		}
		return this._value;
	}
	/**
	 * Get the wrapped value without forcing evaluation.
	 */
	get rawValue() {
		return this._value;
	}
	/**
	 * Create a new lazy value that is the result of applying `f` to the wrapped value.
	 *
	 * This does not force the evaluation of the current lazy value.
	 */
	map(f) {
		return new Lazy(() => f(this.getValue()));
	}
}