Re: [PATCH] Handle case where `beg` and `end` are strings instead of markers

[James N. V. Cash <james.nvc@gmail.com>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>>> +  (let ((beg (if (number-or-marker-p beg)
>>> +                 beg
>>> +               (save-excursion
>>> +                 (goto-char (minibuffer-prompt-end))
>>> +                 (search-forward beg))))
>>> +        (end (if (number-or-marker-p end)
>>> +                 end
>>> +               (save-excursion
>>> +                 (goto-char (point-max))
>>> +                 (search-backward end)))))
>>
>> What if there are several matches for `beg` and/or for `end` in
>> the buffer?  How do we know we got the intended one?
>
> IIUC part of the purpose of using strings rather than positions is to
> account for the case where the text was modified between the moment the
> *Completions* list was created and the moment the user selects one of
> the options.  So another question is what to do if the search fails (the
> above code signals an error in that case, which is probably not what we
> want).

That is a good question. That would happen, I guess, if you had selected
multiple candidates in a CRM, started completing, then deleted the
previously entered candidates, then selected one. I suppose I'd expect
it to add the completed candidate to the end of the remaining list?
So something like

  (let ((beg (if (number-or-marker-p beg)
                 beg
               (save-excursion
                 (goto-char (minibuffer-prompt-end))
                 (or (search-forward beg nil t)
                     (search-forward-regexp crm-separator nil t)
                     (minibuffer-prompt-end)))))

James