Re: delete-selection-mode as default (WAS: Some developement questions)

[Yuri Khan <yurivkhan@gmail.com>]

On Fri, Sep 7, 2018 at 10:37 PM Drew Adams <drew.adams@oracle.com> wrote:

> Exactly the same reasoning was presented in arguments against
> turning on `transient-mark-mode' by default.

My experience with other editors says the following three features are
closely related. (The terminology varies from editor to editor, of
course.)


1a) Region selection is persistent. You can mark a region, then move
point outside of it and it stays highlighted and active.

1b) Region selection is transient. As soon as you move point in a way
other than extending selection, it is deactivated.


2a) Newly entered text is inserted at point without affecting the
selected region, whether or not it is active. Backspace and Delete
keys affect the characters before and after point.

2b) Newly entered text replaces the selected region. Backspace and
Delete keys delete the selected region.


3a) You select a region by pressing a key (or key combination or
sequence), at one end, then moving point to the other end and pressing
another key there.

3b) You select a region by moving point with Shift held down.


Many “classic” editors had [1a, 2a, 3a]. Most “modern” editors have
[1b, 2b, 3b]. These two combinations are consistent and useful. Mixing
and matching may feel weird and/or invite mistakes.

E.g., mixing 1a with 2b, you can have a persistent region, then move
point so that you no longer see the region, so you effectively forget
you have an active region. Then, typing new text and having it replace
the region is surprising, in a bad way.