Topic: need help with explaination of catch:OnError

[taner]

Dear all,

There is a function as below:(http://www.xdcad.net/forum/showthread.php?s=&threadid=13775)

Code: [Select]

(defun catch-error (catch:Protected catch:OnError / catch:err)
    (setq catch:err
       (vl-catch-all-apply catch:Protected)
    )
    (if (and (vl-catch-all-error-p catch:err)
             catch:OnError
        )
        (Apply catch:OnError
           (list (vl-catch-all-error-message catch:err))
        )
        catch:err
    )
 )

I can not understand the argument about catch:OnError , I need some more detailed explaination about it. It is good to give me an example.

Thanks in advance.

[FengK]

catch:OnError is a function to be called when the function catch:Protected fails. try writing a couple of functions to test. if you need help, one of the members will jump in.

[taner]

I understand it all at a once!

[CAB]

Here is another routine:
http://forums.augi.com/showthread.php?p=796998#post796998