Visual Object Definition Language

This paper discusses a declarative constraint-based picture definition language, Vodl, which serves as a graphical basis for visual language specification and visual programming environments. Our goal is to examine the utility of a formal description of graphical tokens and visual languages for the purpose of increasing the understanding of and the development of general methods for graphical languages. Note: Supported in part by the Netherlands Organization for Scientific Research (NWO) under the Generic Tools for Program Analysis and Optimization project. 1 Introduction Special purpose languages with rich programming environments have allowed so-called "nonprogrammers " to effectively carry out programming tasks. Such languages are designed to be well suited for particular tasks for end-users and are typically accompanied with user-friendly graphical interfaces to ease programming tasks. Graphics is widely used in programming environments for easing the programming process for the ..