Re: draft-ietf-impp-cpim-msgfmt syntax

Derek,

Monday, November 11, 2002, 7:30:41 AM, you wrote:
Derek> The justification for MsgFmt,

I think that it is a Good Thing to have a MsgFmt specification. I initiated
this thread to raise a question about the "strategy" of the syntax choice,
not to raise any question at all about the basic utility of SOME MsgFmt
specification.

(There can be a separate discussion about the role of this spec with respect
to the IM service definition, particularly with respect to whether to
mandate it. But that is a discussion about the service, not the format
spec.)

Debating syntax can be pretty big waste of time. That is why I am trying to
raise this in the context of *strategic* impact for the current choice.

There is nothing wrong with the current spec, from a computer science
standpoint. And a desire to clean up and simplify an old, crufty syntax is a
Good Thing. The real question is a kind of strategic make-vs-buy concern, in
terms of global implementation and adoption.

This has nothing to do with the initial coding effort of an individual
programmer. In fact, differences in initial coding effort are almost
completely irrelevant to a question of global adoption and interoperability.
However the difference between no coding, versus some coding, *is*
significant.

The concern is for a) minimizing effort, and b) maximimizing
interoperability with other systems.

Standards work suffers pretty serious multiplier effects.  Small bits of
writing cause large amounts of programming (per programmer and then, of
course, multiplied by the number of such efforts), and larger amounts of
debugging, and even larger amounts of deployment hassle.  The less
development, the lower the risk of a problem down the line.

Interoperability with other messaging systems argues for a semantic that
directly maps to Internet Mail.  I think the current spec is well within
that.  The things that prevent the syntax from being a strict subset of
RFC2822 does not prevent it from being gatewayed (translated), I believe.

So, I think that it is particularly important for MsgFmt to use an existing
syntax and a semantic that is a profile of Internet Mail.  I think the
current spec does the latter.  That just leaves the *strategic* question of
whether to make people write a brand new parser or whether to use an
existing one.

Choosing an Internet Mail parser, and then profiling the semantic, is a very
safe choice.  However I think that at this point it is the wrong choice.
XML has made far too much real progress.  It now comes with a very rich base
of software.

The concern for the space inefficiency of XML is reasonable, but I believe
it is misplaced.  As I think I noted, it is particularly ironic to have the
RFC733/822/2822 syntax considered to be a space-efficient choice.  This
original reactions to it were rather different...

However the reality of the syntactic inefficiencies of XML for messaging
turn out to be misplaced.

If a message is small, the percentage of "waste" is quite high.  But because
the message is small, it doesn't matter.

If a message is large, the bulk of the space is the content, not the
headers.  So, the inefficiencies of the header syntax won't matter.

d/
-- 
 Dave Crocker  <mailto:[email protected]>
 TribalWise <http://www.tribalwise.com>
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