Questions on error trapping

[JaCAD]

Hey all!

The common practice is to use :

(setq TempErr *ERROR*) to store the current error trap in a variable for restoring it at the end of the function.

And then use (setq *ERROR* CurrErrTrap) to point to the new error trap, which is defined elsewhere.

I've been playing around with defining functions inside of other functions, and one of the things I tried was defining an *ERROR* function inside of another function, and adding *ERROR* to the scoped variable list. It seems to me that this gets around needing to use a temporary variable and needing to ensure that it gets reset at the end.
Am I missing something? or is this actually clever?

[BeKirra]

There are a plenty of threads in this forum.
Have you done a search in this forum?
You can see some of them are shown at the bottom of this page under "Similar Threads". And they give rich source on the the topic.
Hope they help.

[JaCAD]

I did search the forum for error trapping, and didn't find anything discussing my specific idea. The "Similar Threads" were helpful for unrelated tasks, but not the idea that I posted about.

[BlackBox]

'Error trapping', or 'error handling' is a popular topic, and can be accomplished in more than one way.

Defining a local *error* function, is just as effective as defining a separate function dependency. Using the IF, AND, OR, COND, and WHILE functions are also able to trap errors (among others).

Just be careful to change variables back to their original value upon error/exit.

Hope this helps!