AutoLISP Developer's Guide (AutoCAD 2013)

AutoDesk, 2012. — 178 p.AutoLISP is a programming language designed for extending and customizing the functionality of AutoCAD. It is based on the LISP programming language, whose origins date back to the late 1950s. LISP was originally designed for use in Artificial Intelligence (AI) applications, and is still the basis for many AI applications.
AutoLISP was introduced as an application programming interface (API) in AutoCAD Release 2.1, in the mid-1980s. LISP was chosen as the initial AutoCAD API because it was uniquely suited for the unstructured design process of AutoCAD projects, which involved repeatedly trying different solutions to design problems.
Developing AutoLISP programs for AutoCAD is done by writing code in a text editor, then loading the code into AutoCAD and running it. Debugging your program is handled by adding statements to print the contents of variables at strategic points in your program. You must figure out where in your program to do this, and what variables you need to look at. If you discover you do not have enough information to determine the error, you must go back and change the code by adding more debugging points. And finally, when you get the program to work correctly, you need to either comment out or remove the debugging code you added.