visual programming language (language) (VPL) Any programming language that allows the user to specify a program in a two-(or more)-dimensionsional way. Conventional textual languages are not considered two-dimensional since the compiler or interpreter processes them as one-dimensional streams of characters. A VPL allows programming with visual expressions - spatial arrangements of textual and graphical symbols.
VPLs may be further classified, according to the type and extent of visual expression used, into icon-based languages, form-based languages and diagram languages. Visual programming environments provide graphical or iconic elements which can be manipulated by the user in an interactive way according to some specific spatial grammar for program construction. A visually transformed language is a non-visual language with a superimposed visual representation. Naturally visual languages have an inherent visual expression for which there is no obvious textual equivalent. Visual Basic, Visual C++ and the entire Microsoft Visual family are not, despite their names, visual programming languages. They are textual languages which use a graphical GUI builder to make programming interfaces easier. The user interface portion of the programming environment is visual, the languages are not. Because of the confusion caused by the multiple meanings of the term "visual programming", Fred Lakin has proposed the term "executable graphics" as an alternative to VPL. Some examples of visual programming languages are Prograph, Pict, Tinkertoy, Fabrik, CODE 2.0 and Hyperpascal. http://cogs.susx.ac.uk/users/ianr/vpl.html. http://cuiwww.unige.ch/eao/www/readme.html. Usenet newsgroup: news:comp.lang.visual (NOT for Visual Basic or Visual C++). Last updated: 1995-02-10
