Re: [PATCH] Possibility of using alternative separators in macros

[Christian Moe <mail@christianmoe.com>]

I frequently need to escape commas in macros, which is a bit of a pain
and easy to forget. My most frequent use case is a macro that expands in
ODT export to a margin comment (like #+begin_annotation does, but
without causing a line break). It takes one argument which typically
consists of several lines of text with commas in them. If I forget to
escape a comma, the rest of the comment is silently lost to the reader.

So a backwards-compatible remedy would be nice. Juan's/Nicholas's
solution is smart, but I'm not sure if it's exactly what I've been
waiting for. It saves escaping every comma, but I'd still have to
remember to add the separator character every time I *invoke* a macro,
and remembering is the tricky part. I don't know if you've already
considered the option of instead specifying a different separator in the
macro *definition*, say something like

  #+macro: comment @@html:<!-- $1 -->@@ :sep "&"

Another point: Something that would help, without adding new syntax, is
making macro expansion smart enough to *ignore* separators when the
macro definition contains only *one* argument anyway, as in the cases
above. That behavior would also be safely backwards-compatible, I
think. It would not help with macros with more than one arg, like Juan's
example, but it would solve most of my problems, for example.

Yours,
Christian


Juan Manuel Macías writes:

> Hi all,
>
> Thanks for your comments, Bastien and Nicolas.
>
> I think macros can work out of the box as a perfect 'backend' for those
> LaTeX commands that include at least one argument with textual content.
> In my case they are very useful to 'extend' the markup language. Apart
> from the LaTeX example that I put previously
> (\foreignlanguage{lang}{short-text}), there are commands like
> \textsc{text in small caps}, \textcolor{color}{text}, and so on. When
> one of the arguments consists of textual content, even if it is a short
> text, it can be tedious to escape constantly commas[1]. Anyway, I
> understand that my use case may not be that of the rest of the users,
> and what is a 'problem' for me, it may not be seen as a problem by other
> users; therefore, I fully understand Bastien's warnings about making a
> modification to something that already works fine, and has been working
> fine since always.
>
> Nicolas's suggestion seemed the most reasonable, or the least
> destructive, in the hypothetical scenario that there would be a great
> demand among users of an alternative separator. Now I see unlikely,
> however, that such a demand exists ;-) So, if my use case is a minority,
> of course I agree with give up this proposal...
>
> [1] To mitigate 'comma issue' I wrote a function that escapes commas
> when saving document :-D
>
> Best regards,
>
> Juan Manuel
>
> Nicolas Goaziou writes:
>
>> Hello,
>>
>> Bastien <bzg@gnu.org> writes:
>>
>>> thank you for the patch.  I understand the general idea, but I think
>>> we should be careful not to overload the macro syntax - escaping the
>>> coma seems okay to me.  I'm closing this suggestion.
>>>
>>> I'm cc'ing Nicolas: if he thinks it's a useful addition, I won't of
>>> course insist on rejecting it.
>>
>> This is a followup to a previous discussion in this mailing list, in
>> which Juan Manuel explained his use-case for a different argument
>> separator in macros. I noticed then that there was an opening for
>> a backward compatible syntax extension for it. As I was also not certain
>> it would be a good idea overall, I suggested him to start a new, more
>> visible, thread with the proposal, and collect feedback.
>>
>> So, maybe it is a bit early to close it.
>>
>> BTW, I would like to amend the proposed syntax, so as to limit friction
>> with the rest of Org. What would be more reasonable is the following:
>>
>>    {{{macroname·(...)}}}
>>
>> where · is either nothing or a _single_ printable non-alphanumeric
>> non-space non-parenthesis character that isn't already meaningful in
>> Org. For example, if for some reason, we limit ourselves to ASCII
>> characters only, the set of allowed separators would be:
>>
>>                        !   %   &   ,   ;   ?   `
>>
>> So, again, I'm not saying we should do this. TBH, I'm not convinced by
>> the idea of duplicate syntax (comma-escaping and alternate characters)
>> for the same thing. But hard-core macro users may have a word to say
>> about it.
>>
>> WDYT?
>>
>> Regards,