SQL Operations Studio Public Preview 1 (0.23) release source code

src/vs/base/common/functional.ts

@@ -0,0 +1,28 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+export function not<A>(fn: (a: A) => boolean): (a: A) => boolean;
+export function not(fn: Function): Function {
+	return (...args) => !fn(...args);
+}
+
+export function once<T extends Function>(fn: T): T {
+	const _this = this;
+	let didCall = false;
+	let result: any;
+
+	return function () {
+		if (didCall) {
+			return result;
+		}
+
+		didCall = true;
+		result = fn.apply(_this, arguments);
+
+		return result;
+	} as any as T;
+}