Diagram Control and Model Order for Sugiyama Layouts

Graphical wysiwyg editors for programming languages are popular since they allow to control the diagram layout to express intention via secondary notation such as proximity and topology. However, such editors typically require users to do manual layout. Conversely, automatic layout of diagrams typically fails to capture intention because graphs are usually considered to not contain any order. Model order can combine the desire for control of secondary notation with automatic layout, without additional overhead, since the textual model already employs secondary notation. We illustrate how model order can exert control on the example of the programming languages SCCharts and Lingua Franca and collect developer feedback to validate our findings.