bug#21391: 24.5; `thing-at-point' returns error when called with arguments 'number t)

[Andreas Röhler]

On 07.11.2016 18:37, Drew Adams wrote:
> > > `thing-at-point' should always return a string.
> > Indeed. Which would require some normalization WRT number-at-point
> > etc.
> `number-at-point' uses `form-at-point'.  It returns a number (or nil),
> not a numeral (string).  It satisfies `numberp', not `stringp'.
>
> What normalization do you have in mind?

Still think detecting buffer-substrings according to THING and returning 
them if found at  point --nil otherwise-- is most straightforward.


> (I have also `decimal-number-at-point' and `hex-number-at-point', FWIW.)
>
> > > `list-at-point', `form-at-point', etc. are a different
> > > story - they can return anything.
> > Interesting question. Maybe returns the symbol if found - nil
> > otherwise?
> That's what `symbol-at-point' does.

Unfortunately it does more - it might change the symbol-table. Expect a 
passive, plain report instead.


>    However, since `nil' is a
> symbol, `symbol-at-point' does not distinguish between finding
> that symbol and not finding any symbol at point.
>
> The others return a thing of the given type (or nil, if none).
>
> `list-at-point', like `symbol-at-point', does not distinguish
> between an empty list at point (buffer text "nil" or "()" or "(  )"
> etc.) and no list at point.  The doc for `list-at-point' should in
> fact say that it returns the _non-nil_ list at point, or nil if none.
>
> It should also return the list (quote (1 2)) when on '(1 2) (it's
> broken, IMO).  (I also have a function `unquoted-list-at-point'.)