[html] split extension (for #45900)

extensions/html-language-features/server/src/utils/arrays.ts

@@ -0,0 +1,77 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+'use strict';
+
+export function pushAll<T>(to: T[], from: T[]) {
+	if (from) {
+		for (var i = 0; i < from.length; i++) {
+			to.push(from[i]);
+		}
+	}
+}
+
+export function contains<T>(arr: T[], val: T) {
+	return arr.indexOf(val) !== -1;
+}
+
+/**
+ * Like `Array#sort` but always stable. Usually runs a little slower `than Array#sort`
+ * so only use this when actually needing stable sort.
+ */
+export function mergeSort<T>(data: T[], compare: (a: T, b: T) => number): T[] {
+	_divideAndMerge(data, compare);
+	return data;
+}
+
+function _divideAndMerge<T>(data: T[], compare: (a: T, b: T) => number): void {
+	if (data.length <= 1) {
+		// sorted
+		return;
+	}
+	const p = (data.length / 2) | 0;
+	const left = data.slice(0, p);
+	const right = data.slice(p);
+
+	_divideAndMerge(left, compare);
+	_divideAndMerge(right, compare);
+
+	let leftIdx = 0;
+	let rightIdx = 0;
+	let i = 0;
+	while (leftIdx < left.length && rightIdx < right.length) {
+		let ret = compare(left[leftIdx], right[rightIdx]);
+		if (ret <= 0) {
+			// smaller_equal -> take left to preserve order
+			data[i++] = left[leftIdx++];
+		} else {
+			// greater -> take right
+			data[i++] = right[rightIdx++];
+		}
+	}
+	while (leftIdx < left.length) {
+		data[i++] = left[leftIdx++];
+	}
+	while (rightIdx < right.length) {
+		data[i++] = right[rightIdx++];
+	}
+}
+
+export function binarySearch<T>(array: T[], key: T, comparator: (op1: T, op2: T) => number): number {
+	let low = 0,
+		high = array.length - 1;
+
+	while (low <= high) {
+		let mid = ((low + high) / 2) | 0;
+		let comp = comparator(array[mid], key);
+		if (comp < 0) {
+			low = mid + 1;
+		} else if (comp > 0) {
+			high = mid - 1;
+		} else {
+			return mid;
+		}
+	}
+	return -(low + 1);
+}