src/vs/workbench/contrib/codeEditor/browser/languageConfigurationExtensionPoint.ts/LanguageConfigurationFileHandler/_mapIndentationRules
class LanguageConfigurationFileHandler:	private _mapIndentationRules(languageId: string, indentationRules: IIndentationRules): IndentationRule | undefined {
		const increaseIndentPattern = this._parseRegex(languageId, `indentationRules.increaseIndentPattern`, indentationRules.increaseIndentPattern);
		if (!increaseIndentPattern) {
			return undefined;
		}
		const decreaseIndentPattern = this._parseRegex(languageId, `indentationRules.decreaseIndentPattern`, indentationRules.decreaseIndentPattern);
		if (!decreaseIndentPattern) {
			return undefined;
		}

		const result: IndentationRule = {
			increaseIndentPattern: increaseIndentPattern,
			decreaseIndentPattern: decreaseIndentPattern
		};

		if (indentationRules.indentNextLinePattern) {
			result.indentNextLinePattern = this._parseRegex(languageId, `indentationRules.indentNextLinePattern`, indentationRules.indentNextLinePattern);
		}
		if (indentationRules.unIndentedLinePattern) {
			result.unIndentedLinePattern = this._parseRegex(languageId, `indentationRules.unIndentedLinePattern`, indentationRules.unIndentedLinePattern);
		}

		return result;
	}