bug#26925: Improve /doc/lispref/strings.texi (split-string) documentation

[Jean-Christophe Helary]

> On 2017/06/04, at 16:49, Michael Albinus <michael.albinus@gmx.de> wrote:
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> Hi Eli,
> 
>>>>> It's up to you. I thought it was weird that all the other
>>>> optional arguments were not labeled as "optional" and only this
>>>> one.
>>>> 
>>>> That's not what I see: grepping the ELisp manual for "optional
>>>> argument" comes up with more than 200 hits.  It's quite normal to use
>>>> that.
>>> 
>>> I am talking about this function. This function does not use
>>> "optional arguments" for its other optional arguments.
>> 
>> Sorry, but I don't see that as a significant evidence.  There's
>> nothing special about this function that would cause us to treat it
>> any different from the rest.
>> 
>> Once again, these are matters of personal style, and IMO we shouldn't
>> make changes motivated by style preferences alone.
> 
> I don't believe Jean-Christophe is speaking about his personal style. He
> claims that two different personal styles are used in the `split-string'
> description in the lispref manual: SEPARATORS and OMIT-NULLS are
> described as arguments, and TRIM is described as "optional argument"
> explicitely. He proposes to harmonize this, which I support.

That's correct. Sorry if my wording made that unclear.

> And btw, the docstring of `split-string' does not speak about TRIM as
> "optional argument" either.

Indeed.

When I modified the documentation the other day I just copy-pasted the trim 
documentation from the *end* of the function documentation (after the examples) 
to its beginning (following the other arguments description *before* the 
examples) and  missed that lack of harmonization. That's something I should 
have fixed then. Sorry for that.

Jean-Christophe