资料来源 : Free On-Line Dictionary of Computing
visual programming 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 language}s. {Visual
programming environment}s 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://www.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++}).
(1995-02-10)