src/vs/workbench/contrib/tasks/common/problemMatcher.ts/ProblemMatcherParser/createRegularExpression
class ProblemMatcherParser:	private createRegularExpression(value: string | undefined): RegExp | null {
		let result: RegExp | null = null;
		if (!value) {
			return result;
		}
		try {
			result = new RegExp(value);
		} catch (err) {
			this.error(localize('ProblemMatcherParser.invalidRegexp', 'Error: The string {0} is not a valid regular expression.\n', value));
		}
		return result;
	}