A visual environment for visual languages

The visual environment GENGED supports the visual definition of visual languages (VLs). Each VL is defined by an alphabet and a grammar. From a specific VL-definition, a VL-specification is generated which is the input of a graphical editor allowing for syntax-directed editing of diagrams over the specified VL. GENGED as well as each VL is based on the well-defined concepts of algebraic graph transformation and graphical constraint solving. The underlying formalism is hidden from the user, but it is essential for a formal presentation and manipulation of graphical structures. In this contribution, the GENGED concepts and environment are briefly proposed and illustrated by the definition of a simple kind of the well-known statechart language.