How to use this reference

How to use this reference

In the function definitions below, bold words are types, and are not part of CLIPS syntax. Parameter names are in italics. Types are as follows:

double is a double-precision floating point number.
long is a long integer.
string is a double-quoted ASCII string.
word is an unquoted string.
multifield is a CLIPS multi-field value list.

Parameters can be optional, in which case defaults are assumed.

Some parameters can be bit lists of flags. wxCLIPS mimics the compact C++ syntax by parsing strings, for example:

  (frame-create ... "wxSDI | wxDEFAULT")

Each identifier in such a parameter is translated to an integer value, and all are logical-or'ed together to produce an integer which is passed to the appropriate wxWindows C++ function.

Note: In Windows NT or WIN32s versions of Hardy, integer identifiers can be negative. So when validating integer identifiers, test for values of zero or -1, rather than for values less than zero.

Functions are grouped by class: in the underlying C++ library wxWindows, these are actual C++ classes. The functions are used in an object-oriented way, in that long integer identifiers represent an object, or instance, of a particular class. Some functions operate on several classes of object; for example, the functions prefixed window operate on classes derived from window, such as canvas, frame, dialog box, panel item. Similarly, the functions prefixed dc operate on different kinds of device context.

Most functions either take an integer identifier (checking its type before doing the appropriate thing) or return a new one.

In C++, the application would derive new classes and override certain member functions, such as OnClose, to intercept messages or events sent to the window objects. In CLIPS, the same effect is achieved by registering callback functions for specific events, using window-add-callback.