[NTG-context] Check for parity of pair tags on source file to be closed

[context at vivaldi.net]

Hello,

in most cases, when a source file is to be closed, pair elements (tags) 
should balanced.

This concerns e.g. { - }, \bgroup - \egroup, \startitemize - 
\stopitemize, \if - \fi etc.

When we have a complicated project structure and when compiling the 
topmost (root) source, a log for a disbalanced tag may appear, but the 
unbalanced tag however may be difficult to find.

Is there a way to enable "watching" pair tags (at least mentioned 
before) in the way that their disbalance would be reported (logged)?

Maybe a "enable tracker" could provide that...

Sample:

---- A.mkiv
\starttext
   A
   \input B.mkiv
\stoptext

---- B.mkiv
   \startitemize
     \item B
---- <- "\startitemize" is unbalanced (unfinished by \stopitemize) in 
the scope of B.mkiv,
         so a message/log ("unfinished \startitemize") should be printed 
when B.mkiv is to be closed.

Best regards,

Lukas