compute(editorModel: ITextModel): TPromise<FoldingRegions> {
let foldingRules = LanguageConfigurationRegistry.getFoldingRules(editorModel.getLanguageIdentifier().id);
let offSide = foldingRules && foldingRules.offSide;
let markers = foldingRules && foldingRules.markers;
return TPromise.as(computeRanges(editorModel, offSide, markers));
}