[O] syntax specification (was Re: Bug: [regression] superscript not available after non-alphanumeric)

[heroxbd]

Hi Nicolas,

Nicolas Goaziou <address@hidden> writes:

> If you want to insert raw LaTeX in an Org buffer, then \ce{^{238}U} is
> invalid because you cannot nest braces. You can write instead:
>
>   @@latex:\ce{^{238}U}@@
>
> or you can define a macro, e.g.,:
>
>   #+MACRO: ce @@latex:\ce{$1}@@
>
> and then use
>
>   {{{ce(^{238}U)}}}
>
> Also, ^2H is not recognized as superscript _on purpose_. Per Org syntax,
> you have to add a non-blank character before the caret. Otherwise, there
> would be ambiguity between underline (e.g., _under_) and subscript
> (_under). And superscript syntax follows subscript's.
>
> In this case, you can probably use a math snippet, e.g.,
>
>   \(^2\)H

Thank you for the explanation.  I got to know what went wrong.

I am wondering where the claims "you cannot nest braces" and "Per Org
syntax, you have to add a non-blank character before the caret" come
from.  Is there a general principle guideline for the org syntax, or is
it a taste of the maintainer only?

Is it true when an exporter maintainer changes, the syntax changes to
his somehow incompatible preference?  In [1], Carsten regarded "you have
to add a non-blank character before the caret" as a bug and fixed it;
while you regard it as a rule.  I am curious about what was the
compelling motivation to make this shift.

Interpreting \ce{^{238}U} directly complicates the exporter parser
logic, while gives LaTeX composers a syntax sugar.  The inconvenience of
"\(^2\)H" is similar to "\_leading_under_line".  Either syntax is not
superior to the other.  Maintaining a stable syntax is the principle in
this case.

Don't get me wrong.  I appreciate and respect your new-school exporting
framework, and the sexy features it makes possible.  I am to express my
value and concern on the longterm specification (and consequently
usability) of the org syntax.

Cheers,
Benda

1. http://lists.gnu.org/archive/html/emacs-orgmode/2009-09/msg00887.html