[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

bug#17235: Undo in region adjusts past positions incorrectly

From: Stefan Monnier
Subject: bug#17235: Undo in region adjusts past positions incorrectly
Date: Tue, 22 Apr 2014 22:31:38 -0400
User-agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4.50 (gnu/linux)

> I think the algorithm would be simpler to make correct if adjustments
> are applied forward chronologically rather than backwards. That is,
> the algorithm keeps a list of undo-deltas that grows as the algorithm
> iterates backwards through undo history. As it does so, the positions
> are adjusted chronologically forward through the undo-deltas. This
> approach is O(N**2), as the current algorithm also is, but the bright
> side is the proposed algorithm lends itself to short circuiting better
> than the current.

I believe you.  I'm not familiar with the way it currently works.

> Let me know if you have other ideas and I'll prepare a patch.

While looking at that code, can you make that "make-selective-list" skip
redo entries (depending on undo-no-redo, obviously), using the


reply via email to

[Prev in Thread] Current Thread [Next in Thread]