src/vs/base/common/filters.ts/isWhitespaceAtPos
function isWhitespaceAtPos(value: string, index: number): boolean {
	if (index < 0 || index >= value.length) {
		return false;
	}
	const code = value.charCodeAt(index);
	switch (code) {
		case CharCode.Space:
		case CharCode.Tab:
			return true;
		default:
			return false;
	}
}