Re: A suggestion to add to gnu ed: command line option to start on line foo or bar.

[John Cowan]

On Wed, Mar 8, 2023 at 11:41 AM Antonio Diaz Diaz <antonio@gnu.org> wrote:


> I think your definition of "fairly small wish-list item" differs from
> mine. ;-)
>

Perhaps.  Since I don't know the code base, I was primarily concerned with
how easy they are to specify rather than how easy they are to implement.

> As you surely know, ed is mostly of historical interest.
>

My primary editor is ex, specifically the ex mode of vim.  I would like to
switch to ed, as it is much lighter-weight than vim and overall less
buggy.  So I decided to write down the features that, if added to ed, would
help me make this switch.  Of course some would be better than none.

> Some of your proposals seem pretty specialized, and others are
> contradictory
> ('R rewind' and 'R multi-level redo). ''


Sure.  If both were implemented, R would have to be assigned to one or the
other.  An alternative would be to use N for movement between files in
either direction: N+ to move to the next file, N- to move to the previous
file, Nn (where n is a digit sequence) to move to the nth file, so that
rewind would be N1.

> Therefore I would like to see some
> kind of consensus among ed users in this list before thinking about
> implementing any of them.
>

I too would like to hear from other members of this list which features
they would use.


> The shell escape command (!) can't have default addresses and remain
> backwards compatible.


Technically so, in the sense that Posix says it is an error.  However,
reporting an error is unlikely to be a feature that anyone depends on.  I
would not object to blocking this feature if POSIXLY_CORRECT is defined, or
alternatively gating it behind a new variable ED_EXTENSIONS.

Thanks for the quick response.  I look forward to hearing your comments in
detail whenever you are able to provide them.