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

extensions/git/src/iterators.ts

@@ -0,0 +1,57 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+function* filter<T>(it: IterableIterator<T>, condition: (t: T, i: number) => boolean): IterableIterator<T> {
+	let i = 0;
+	for (let t of it) {
+		if (condition(t, i++)) {
+			yield t;
+		}
+	}
+}
+
+function* map<T, R>(it: IterableIterator<T>, fn: (t: T, i: number) => R): IterableIterator<R> {
+	let i = 0;
+	for (let t of it) {
+		yield fn(t, i++);
+	}
+}
+
+export interface FunctionalIterator<T> extends Iterable<T> {
+	filter(condition: (t: T, i: number) => boolean): FunctionalIterator<T>;
+	map<R>(fn: (t: T, i: number) => R): FunctionalIterator<R>;
+	toArray(): T[];
+}
+
+class FunctionalIteratorImpl<T> implements FunctionalIterator<T> {
+
+	constructor(private iterator: IterableIterator<T>) { }
+
+	filter(condition: (t: T, i: number) => boolean): FunctionalIterator<T> {
+		return new FunctionalIteratorImpl(filter(this.iterator, condition));
+	}
+
+	map<R>(fn: (t: T, i: number) => R): FunctionalIterator<R> {
+		return new FunctionalIteratorImpl(map<T, R>(this.iterator, fn));
+	}
+
+	toArray(): T[] {
+		return Array.from(this.iterator);
+	}
+
+	[Symbol.iterator](): IterableIterator<T> {
+		return this.iterator;
+	}
+}
+
+export function iterate<T>(obj: T[] | IterableIterator<T>): FunctionalIterator<T> {
+	if (Array.isArray(obj)) {
+		return new FunctionalIteratorImpl(obj[Symbol.iterator]());
+	}
+
+	return new FunctionalIteratorImpl(obj);
+}