Subject: bug#17603: Emacs enhancement request

From: Stefan Monnier <[email-masked]>
Date: Tue, 27 May 2014 21:10:41 -0400

> I am an avid user of GNU Emacs and I love using Tex mode to write my
> documents. However one of the features that I find lacking in Emacs is
> *auto-complete*. By that I don't mean the common feature found in other IDE
> for programmers but the following. Suppose I already typed up a formula

> *\int_{\mathbb{R}} e^{2 \pi i x^2} dx = 1*

> And after paragraph or so I want to repeat the same thing all over again
> (and maybe modify *x* to *y*). Of course I can search+save region+yank but
> that's too manual. What I wish to have is if I typed *\int* and then
> invoked the *auto-complete *command, Emacs would move the point to the
> previous instance of *\int* and allow me to mark a region around it. After
> marking I could hit *Enter* and Emacs would copy the highlighted part and
> put it to the partially completed *\int* below. I also want to be able to
> cycle through previous instances of *\int* with the up and down arrow keys,
> much like using *isearch*.

What you describe (including letting you mark the region around the
previous match) sounds sufficiently complex (UI-wise) that using

  C-SPC C-r *\int ..copy text.. C-u C-SPC C-y

wouldn't be noticeably more complex.
So I think it only makes sense to provide such a feature if the choice
of the amount to copy can be made somewhat automatic.

Maybe hippie-expand's try-expand-line would work for you?

        Stefan