Re: Lisp Syntax for external representation [Was: URC usage scenarios ]

Dirk Herr-Hoyman (hoymand@gate.net)
Fri, 30 Sep 1994 07:43:12 -0400

Date: Fri, 30 Sep 1994 07:43:12 -0400
Message-Id: <199409301143.HAA73450@inca.gate.net>
To: uri@bunyip.com
From: hoymand@gate.net (Dirk Herr-Hoyman)
Subject: Re: Lisp Syntax for external representation [Was: URC usage scenarios ]

At 12:31 PM 9/29/94 -0500, Daniel W. Connolly wrote:
>In message <199409291654.KAA00857@idaknow.acl.lanl.gov>, rdaniel@acl.lanl.gov w
>rites:
>>Perhaps the syntax of the URC should be changed to be of the form:
>>
>> URC.version {
>> elements
>> }
>> signatures
>>
>>I will have a better handle on that as I implement the parser for the
>>URC structure.
>
>I have held my tongue until now, but I just can't bear this any more.
>
>For crying out loud, can we just use Lisp S-Expression syntax for the
>external representation of these things and be done with it?
>
>Why must we invent a new syntax? Why waste time designing,
>implementing, and debugging new technology that is irrelevant to the
>task at hand?

And

>If somebody has a different syntax with years of experience behind it,
>let's see it. I'm willing to hear arguments that Tcl or SGML -- ugly
>as they are -- is the right thing, since they're widely deployed and
>understood. But by the "everything should be as simple as it can be
>and no simpler," you'll have a hard time coming up with something better
>than S-expressions.
>
>But for pete's sake, let's not make something up just to be different.
>
>Dan

Dan, you have several good points to be made here. Clearly Lisp
S-expressions are powerful enough to handle any URC construct.

I would like to think about this first in terms of requirements. Are URCs
meant to be an internal data structure, known only to the s/w involved,
like WAIS? Or, are we intended folks to be able to do their own data
entry?

There appears to be 2 levels of URC constructs that we have batted around:

1. A flat e-mail header structure.
2. A recursive structure.

While there have been some proposals to shoehorn a recursive structure into
an e-mail header, they are just not very clean and prone to all the
practical problems Dan points out.

If we are do propose a recursive structure, a good long look should be
given to an SGML format. Certain this is at least as powerful as
S-expressions and if we constrain it, it could be essentially the same as
S-expressions.

My real reasons for wanting to think about SGML are:

1) SGML is becoming increasingly popular is an electronic document format.
It makes sense to create meta-data in this same format, thus a URC might be
contained within a document. We just saw a proposal for one on this list
today.
I know that TEI has tags for meta-data (quite a few of them actually). So,
this is coming, if not already here.

2) SGML authoring tools are hitting the market. This means we should see
an easy means to do data entry, and have it be syntaxtically correct.

--
Dirk Herr-Hoyman <hoymand@gate.net> |           I tried to contain myself
CyberBeach Publishing               |                                but
   * Internet publishing services   |                          I got out
Lake Worth, Florida, USA            |                          
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