Re: thing-at-point: inconsistent behaviour?

[Raffaele Ricciardi <rfflrccrd@gmail.com>]

On 08/16/2012 05:24 PM, Andreas Röhler wrote:
 > 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

When you are looking for a buffer substring, you call
`bounds-of-thing-at-point'; when you are looking for a string result, 
you call
`thing-at-point'; when you want the result as a sexp, you call the 
specialized
function.

 > 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.

Indeed this is an undesirable side effect of `symbol-at-point' calling
`intern'.  Could `intern' be replaced with `make-symbol'?