Look for data serialisation format to implement communication between Emacs and external program.

[Oleksandr Gavenko <gavenkoa@gmail.com>]

I know that XML is BAD so avoid it.

My experience with 'expect' show me that simple string data communication is
good but some times data have same pattern as _prompt_ so I can't distinct
control data from regular data.

Prefixes like in 'diff' file format resolve this issue. But this move us to
TLV (table-length-value) format.

Standard TLV format described by ASN.1 BER coding schema.

Is that right to use ASN.1 BER as serialisation data format for communication
between Emacs and external program?

My external application is not jet written but I select Python as
implementation language. Seems 'python-pyasn1' library make work from Python
side:

  http://pyasn1.sourceforge.net/

How about Emacs? Is there any library for creating/parsing ASN.1 BER data?

I need only basic types, like structure of numbers and UTF-8 strings (blogging
software - pass command and data like article + title + list of tags)...

Another formats like JSON or sexp also look nice but I don't know about Emacs
support for this formats.

I didn't look yet to projects like pymacs, which solved such task.

Any advice is welcome!

-- 
Best regards!