Specifying Diagram Languages by Means of Hypergraph Grammars

For working with diagrams on a computer screen we need diagram editors, i.e., graphical editors specialized in the specific diagram language. In order to create such a diagram editor in a methodical way, a formal representation of each diagram and of the whole diagram language is required. This paper describes continued work on how to specify a wide range of diagram languages in terms of a hypergraph model together with hypergraph grammars. The specification of a diagram language can serve as input for an automated generator which creates a diagram editor for the specified diagram language. Editors support syntax-directed editing as well as free hand editing of the diagrams on the screen which are internally represented by hypergraphs. For free hand editing, a hypergraph parser is used to obtain the diagrams’ syntactic structure and to distinguish correct diagrams or diagram parts from incorrect ones.