Re: Emacs as a translator's tool

[Eric Abrahamsen]

Emanuel Berg via Users list for the GNU Emacs text editor
<help-gnu-emacs@gnu.org> writes:

> Marcin Borkowski wrote:
>
>> If you find a good way to refactor it so that it is
>> more DRY, I'd love to see it.
>
> ;;; -*- lexical-binding: t -*-
> ;;;
> ;;; this file:
> ;;;   http://user.it.uu.se/~embe8573/emacs-init/incal-ecat.el
> ;;;   https://dataswamp.org/~incal/emacs-init/incal-ecat.el
>
> (defvar sentence-overlay nil)
>
> (defun remove-highlight ()
>   (interactive)
>   (when (overlayp sentence-overlay)
>     (delete-overlay sentence-overlay) ))
>
> (defun highlight-sentence ()
>   (interactive)
>   (remove-highlight)
>   (let ((overlay (make-overlay (progn (forward-sentence)  (point))
>                                (progn (backward-sentence) (point)) )))
>     (overlay-put overlay 'face 'font-lock-function-name-face)
>     (setq sentence-overlay overlay) ))

You don't need to delete the overlay and make it again each time, just
use `move-overlay'. You can also move an overlay that's been deleted,
essentially recreating it, so long as you still have a reference to it.

How do I know? Because this thread finally motivated me to finish the
translation environment package I've been thinking of for a while, and I
just wrote pretty much the same code a couple of days ago :)