On Thu, Jul 5, 2012 at 12:44 AM, Rogers, Michael K <mroge02@emory.edu> wrote:

On Jul 4, 2012, at 1:29 PM, Peter Münster wrote:
> On Wed, Jul 04 2012, Hans Hagen wrote:
>
>> no, mixing this way is asking for troubles, if not now, than maybe in the
>> future
>>
>> just use \section
>
> Yes, but isn't \startsection the recommended method for the future and
> needed for XML output?

XML documents should form a tree, so a structure like

\startA % <A>
\startB % <B>
\stopA % </A>
\stopB % </B>

won't translate to XML.

Grouping in TeX follows the same restrictions, and \start... and \stop... behave like \begingroup and \endgroup. The \stop... is supposed to restore the state before the corresponding \start... (at least I assume so -- \endgroup works that way). One cannot stop A in the middle of B and return to the state before \startA without also stopping B. So one should put \stopB before \stopA, not after it.

It depends.

\starttext

\long\def\startA#1\stopA{<\low{A}#1>\low{A}}

\long\def\startB#1\stopB{<\low{B}#1>\low{B}}

\startA

textAA

\startB

textAB

\stopA

textBB

\stopB

\stoptext

is ok (not the context way, btw: real code is more complex).

The meaning of this can be

content of \startA..\stopA = textAA ⋃ textAB

content of \startB..\stopB = textAB ⋃ textBB

\startA..\stopA ⋂ \startB..\stopB = textAB