Re: abbrevs, skeletons, and comments

[Andreas Roehler]

nobrowser@gmail.com schrieb:
> Tim X wrote:
>   
> > nobrowser@gmail.com writes:
> >
> >     
> > > In a module I'm writing, I'd like to bind abbrevs to code skeletons,
> > > similar to what is done e.g. by sml-mode.  But expanding the abbrevs
> > > makes no sense when the point is inside a comment (or a string
> > > literal).  So I'd like to conditionally stop expansion.  The main
> > > opportunity for that seems to be pre-abbrev-expand-hook, but there are
> > > only two ways it can stop an expansion: 1, throw an error, 2, change
> > > the abbrev bindings (either by making changes in the current table or
> > > by swapping in a whole new table). 1 is unacceptable - how many errors
> > > before user gets mad and disables abbrevs altogether? 2, how to undo
> > > the changes when the point leaves the comment or string?
> > >
> > >       
> > maybe use an error handler that catches that specific error and ignores it?
> >
> >     
>
> Well, there's no point where I get control, that's the problem.
> Abbrev expansion can be triggered just by the user typing a space or
> period, if they have Abbrev minor mode on.
>
> I see a way to do what I want.  It involves hooking both pre-abbrev-
> expand-hook and post-command-hook.  I can restore the abbrev bindings
> in the latter.  But I am afraid what this could do to Emacs speed or
> even stability.
>
> What I've decided on so far is I won't do anything by default (so
> users who avoid Abbrev minor mode are not penalized) and have a
> customize flag that turns on the above solution.
>
> Other suggestions still welcome.
>   

You could write

(unless (in-string-p)
   (expand-abbrev

Concerning comments, you may use

,----
| (defun comment-beginning ()
|   "Find the beginning of the enclosing comment.
| Returns nil if not inside a comment, else moves point and returns
| the same as `comment-search-backward'."
`----


If `font-lock' at point is reliable, another (probably faster)
approach could be

(get-text-property (point) 'face)

to determine if inside a comment.