GenEd - An Editor with Generic Semantics for Formal Reasoning about Visual Notations

We describe the object-oriented editor GenEd supporting the design of specifications for visual notations. Prominent features of GenEd are (1) it is generic, i.e. domain-specific syntax and semantics are specified by users; (2) built-in parser for actual drawings, driven by formal specifications; (3) powerful reasoning capabilities about diagrams and their specification. GenEd's specification language is based on a fully formalized theory for describing visual notations. Three examples, place-transition petri nets, entity-relationship diagrams, and a small GIS application are presented. Keywords--- Theory of visual languages, formal semantics, diagrammatical reasoning, description logics, visual editor, visual parsing, geographical information systems. 1 Motivation and Introduction This paper reports on the design and evaluation of the generic editor GenEd for visual notations. The term "generic" refers to the characteristic that users can specify domain-specific syntax and semantics..