A question about Lee's e

DuanJinHui · 发表于 2022-7-5 17:44:02

code1:

(defun c:test ( / myerr olderr oldcmdecho)(defun myerr ( msg )        (setvar "cmdecho" oldcmdecho)        (LM:endundo (LM:acdoc))        (setq *error* olderr)        (princ "\n*error* inside of test program.")          (princ))(LM:startundo (LM:acdoc))(setq olderr *error*        *error* myerr)(setq oldcmdecho (getvar "cmdecho"))(setvar "cmdecho" 0)(getstring "\nPress Esc to force an error...")(setvar "cmdecho" oldcmdecho)(LM:endundo (LM:acdoc))(setq *error* olderr)(princ))

code2

copy

(defun c:test ( / myerr olderr oldcmdecho)(defun myerr ( msg )        (setvar "cmdecho" oldcmdecho)        (LM:endundo (LM:acdoc))        (setq *error* olderr)        (princ "\n*error* inside of test program.")          (princ))(setq olderr *error*        *error* myerr)(LM:startundo (LM:acdoc))(setq oldcmdecho (getvar "cmdecho"))(setvar "cmdecho" 0)(getstring "\nPress Esc to force an error...")(setvar "cmdecho" oldcmdecho)(LM:endundo (LM:acdoc))(setq *error* olderr)(princ))

Which one is right ?
ps: (LM:startundo (LM:acdoc)) position is not the same.

Lee Mac · 发表于 2022-7-5 18:19:38

There will be no difference as an undo operation will only revert changes to the drawing database & system variables, it will not change variable values.

DuanJinHui · 发表于 2022-7-5 18:27:03

Thanks Lee. Your suggestion is use code2 ?

Lee Mac · 发表于 2022-7-5 18:57:55

Either may be used, but personally I prefer to declare the *error* symbol local to the function such that any redefinition is restored outside of the function scope.

[编程交流] A question about Lee's e

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