🚀 go-pugleaf

>From CSD.HANSEN@SU-SCORE Thu Feb  4 14:51:03 1982
I have several questions concerning an  undo facility in a screen editor  and
would like to get some opinions.

Is an undo facility absolutely necessary? Would you consider using an  editor
which had absolutely NO undo capabilities? Should an editor allow you to undo
ANYTHING? (Including reads  and writes  to files?) Or  should the  capability
extend only to such things as undeleting/unkilling? How about getting rid  of
text  just   inserted?   Probably   global  changes,   such   as   a   global
replace/substitute?

Should an undo facility toggle between states? Should an undo be able to undo
an undo? Or would it be better  to allow a multi-level undo/redo facility  in
which a  user may  march  back in  time to  previous  stages in  the  editing
session, then march  forward again?  If this  were allowed,  how many  levels
would be appropriate? An interesting problem arises if this were allowed:  If
you marched back  4 levels, then  starting inserting text,  would the last  4
changes to the file then be lost? The worst thing you could do at that  point
would be to start making changes without going forward again.

					Tony Hansen
					Csd.Hansen @ Su-Score
					houxs!hansen @ Usenet
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