Re: edit.m and EDITOR

[John W. Eaton]

On 11-Apr-2012, Michael Goffioul wrote:

| On Wed, Apr 11, 2012 at 1:31 PM, John W. Eaton <address@hidden> wrote:
| > On 11-Apr-2012, Mike Miller wrote:
| >
| > | Maybe I'm way off here, but I'll throw in anyway.  I do see a difference
| > | between EDITOR and edit's FUNCTION.EDITOR.  In the context of the edit
| > | command, people seem to want to fork an editor in the background, edit
| > | code while you still have access to the Octave shell.  Indeed, as I
| > | recently learned, the default edit "mode" is now "async".
| > |
| > | For edit_history, the EDITOR is called synchronously a la Unix "fc".  It
| > | must be that way for the results to be useful.  For me, that means I
| > | want it to happen in the same terminal.
| > |
| > | Maybe these are still the same for most people, but for me:
| > |
| > |   octave:1> getenv("EDITOR"), EDITOR, edit get EDITOR
| > |   ans = vim
| > |   ans = vim
| > |   ans = gvim %s
| > |
| > | If these do collapse to one setting, I'm sure I'll be ok :)
| >
| > OK, I didn't realize that the value of EDITOR in the edit function was
| > not just the name of the editor program, but also could contain some
| > format specification.  Ugh.  I don't see a good solution that won't
| > break backward compatibility in some way.
| 
| Well, remember that the initial confusion comes from the fact that the
| edit.m help says it's using EDITOR by default. But that's not entirely
| true, because of FUNCTION.EDITOR being persistent. So whenever edit.m
| is loaded by octave (whatever the reason), FUNCTION.EDITOR is "fixed"
| to "[EDITOR, ' %s']" and any later change of EDITOR variable is
| ignored by edit.m.
| 
| I suggested to solve that confusion by leaving FUNCTION.EDITOR empty
| instead of initializing it to "[EDITOR, ' %s']". Then in the rest of
| edit.m, if FUNCTION.EDITOR is not empty, use it, otherwise use
| "[EDITOR, ' %s']". That way, EDITOR variable will always be honored by
| edit.m, except if the editor has been explicitly overridden by calling
| "edit('EDITOR', ...)".

Although that still leaves some possibility for confusion (the editors
used by edit and edit_history can be unexpectedly different, for
example), it seems like the best solution to me.

jwe