AutoLISP error does not produce command line list dump

XDSoft

问题：
How can I determine in which line of AutoLISP code an error exists?

解答：
In previous versions of AutoLISP and Visual LISP (VLISP), when an AutoLISP
function terminated unexpectedly in the drawing editor, the entire expression
would display on the screen, which made it easy to locate the exact line which
contained the error.  When this situation occurs In AutoCAD 2000, locating the
error is not as easy because only a message such as "Bad argument type:
lentityp' (or stringp)" displays. The error message unfortunately does not state
in which line of code the error exists.

The change in how errors in AutoLISP code are handled is different in AutoCAD
2000 because function are no longer  lists. To locate the error in the code,
youl need to use the Visual Lisp IDE. Although it may require that you learn
about the IDE debug features, you'll find that it's a much better environment to
debug AutoLISP code than in previous releases of AutoCAD.

What you need to do to enable this facility is to perform the following steps:

1.  Open the Visual Lisp IDE at the beginning of your AutoCAD session by typing
VLISP
or VLIDE at the command line.
2.  Select the Debug menu in the IDE, and select 'Break On Error'.
3.  Load your AutoLISP code and run it.

When an error in your code occurs, you'll be put back into the Visual LISP IDE.
All you then need to do to find the line in the code that contains the error is
to select the 'Last Break' option on the Debug Toolbar, or the 'Last Break
Source' from the Debug menu.

There are many more powerful tools available to debug yourAutoLISP code using
the Visual Lisp IDE, To learn about them, refer to the Visual LISP Developer's
Guide, Chapter 3 -- Debugging Programs for more information about the IDE and
its debugging features.