src/vs/workbench/contrib/tasks/common/problemMatcher.ts/createLineMatcher
export function createLineMatcher(matcher: ProblemMatcher, fileService?: IFileService): ILineMatcher {
	const pattern = matcher.pattern;
	if (Types.isArray(pattern)) {
		return new MultiLineMatcher(matcher, fileService);
	} else {
		return new SingleLineMatcher(matcher, fileService);
	}
}