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

78 lines
2.2 KiB
TypeScript

/*---------------------------------------------------------------------------------------------
* 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;
}