Merge commit 'be3e8236086165e5e45a5a10783823874b3f3ebd' as 'lib/vscode'

lib/vscode/extensions/html-language-features/server/src/utils/strings.ts

@@ -0,0 +1,78 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+export function getWordAtText(text: string, offset: number, wordDefinition: RegExp): { start: number, length: number } {
+	let lineStart = offset;
+	while (lineStart > 0 && !isNewlineCharacter(text.charCodeAt(lineStart - 1))) {
+		lineStart--;
+	}
+	let offsetInLine = offset - lineStart;
+	let lineText = text.substr(lineStart);
+
+	// make a copy of the regex as to not keep the state
+	let flags = wordDefinition.ignoreCase ? 'gi' : 'g';
+	wordDefinition = new RegExp(wordDefinition.source, flags);
+
+	let match = wordDefinition.exec(lineText);
+	while (match && match.index + match[0].length < offsetInLine) {
+		match = wordDefinition.exec(lineText);
+	}
+	if (match && match.index <= offsetInLine) {
+		return { start: match.index + lineStart, length: match[0].length };
+	}
+
+	return { start: offset, length: 0 };
+}
+
+export function startsWith(haystack: string, needle: string): boolean {
+	if (haystack.length < needle.length) {
+		return false;
+	}
+
+	for (let i = 0; i < needle.length; i++) {
+		if (haystack[i] !== needle[i]) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+export function endsWith(haystack: string, needle: string): boolean {
+	let diff = haystack.length - needle.length;
+	if (diff > 0) {
+		return haystack.indexOf(needle, diff) === diff;
+	} else if (diff === 0) {
+		return haystack === needle;
+	} else {
+		return false;
+	}
+}
+
+export function repeat(value: string, count: number) {
+	let s = '';
+	while (count > 0) {
+		if ((count & 1) === 1) {
+			s += value;
+		}
+		value += value;
+		count = count >>> 1;
+	}
+	return s;
+}
+
+export function isWhitespaceOnly(str: string) {
+	return /^\s*$/.test(str);
+}
+
+export function isEOL(content: string, offset: number) {
+	return isNewlineCharacter(content.charCodeAt(offset));
+}
+
+const CR = '\r'.charCodeAt(0);
+const NL = '\n'.charCodeAt(0);
+export function isNewlineCharacter(charCode: number) {
+	return charCode === CR || charCode === NL;
+}