Re: thing-at-point: inconsistent behaviour?

[Andreas Röhler]

Am 16.08.2012 17:48, schrieb Barry Margolin:
> In article <mailman.7107.1345117968.855.help-gnu-emacs@gnu.org>,
>   Andreas Röhler <andreas.roehler@easy-emacs.de> wrote:
>
> > Am 15.08.2012 21:00, schrieb Raffaele Ricciardi:
> > > On 08/15/2012 07:34 PM, Barry Margolin wrote:
> > >   > In article <a926tjFeslU1@mid.individual.net>,
> > >   >   Raffaele Ricciardi <rfflrccrd@gmail.com> wrote:
> > >   >
> > >   >> Hello there,
> > >   >>
> > >   >> the documentation of `thing-at-point' states that such function returns
> > >   >> "the
> > >   >> thing around or next to point".  This is not the case with either
> > >   >> (thing-at-point
> > >   >> 'symbol) or (thing-at-point 'sexp), for they both may return the thing
> > >   >> before
> > >   >> point.  Try it with the following snippet (! symbolizes the point):
> > >   >
> > >   > Doesn't "next to" include both immediately before and immediately after?
> > >
> > > I stand corrected after having consulted a dictionary.  Then it is
> > > (thing-at-point 'list) that is misbehaving.
> >
> >
> > hmm, IMHO you was right. Here is the code
> >
> > (defun symbol-at-point ()
> >     "Return the symbol at point, or nil if none is found."
> >     (let ((thing (thing-at-point 'symbol)))
> >       (if thing (intern thing))))
> >
> > last line don't return the thing as delivered by thing-at-point but the
> > result of (intern thing)
> >
> > that way breaking consistency.
>
> That function has nothing to do with the problem he's reporting. It's
> just an extra utility function that makes use of thing-at-point to
> return something that may be useful in certain situations.

okay, as it happens it's for years in my mind: that symbol-at-point breaks 
consistency.

Another approach to give the reasons:

IMO basically two ways of returns are feasible by such a thing-at-point library

- deliver objects from editing perspective, i.e as buffer-substrings
- deliver objects for use in programs

The latter seems the focus so far.

Not to expect is changing the computers internal state already when picking an 
object by thing-at-point.
That's what is done by "intern" however.