xml:id RE: [sc34wg3] Compact syntax requirement question

Patrick Durusau sc34wg3@isotopicmaps.org
Tue, 19 Jul 2005 10:41:22 -0400


Snipping to your last point:

Lars Marius Garshol wrote:


>However, the use case that clinched this for us at the meeting, and
>which every person who has contributed to this thread has ignored so
>far is that we need CTM for TMQL. And TMQL is not going to have an XML
>syntax, which means that whoever is writing TMQL will already be
>writing a plain text syntax.
Not so much ignored as thought to be yet another claim that needs 
further explanation. ;-)

I am not sure "TMQL is not going to have an XML synatx" necessarily 
leads to "will already be writing a plain text syntax."

The Scope statement (first paragraph) says:

> This International Standard defines a formal language by providing a 
> syntax to form query expressions. The
> document also defines an informal and a formal semantics for every 
> syntactic form, including rules for the reporting
> of error conditions.

I took that to mean (perhaps incorrectly) that TMQL was defining a 
formal language for querying topic maps and not a concrete syntax (of 
which there might be several) for querying topic maps. Any concrete 
syntax and its processor would have to follow the strictures defined by 
the formal language defined by TMQL.

In further support of that reading, which I admit may be incorrect, I 
note that 3.1 Notation and Syntax says:

> The syntax of TMQL is defined using the EBNF formalism defined in [XML 
> 1.0].

So TMQL is being defined using EBNF, which I didn't take to mean a 
standard syntax in the sense that most users understand the term.

BTW, I am curious why the reference here is not to the standard EBNF 
formalism rather than that of XML. I have not checked but is there a 
difference? EBNF was not defined by XML 1.0 as I recall. ;-)

Sure, one could write queries using the EBNF as specified in TMQL, but I 
am not sure that assumption is a transparent as some may have thought.

It would also be possible to write an equivalent query language that 
following the rules as specified without being limited to the spareness 
of the EBNF grammar as given.

BTW, compact syntax fans, don't take these questions as being 
unsympathetic to a compact syntax or even one in plain text. I don't 
think one size fits all in almost all circumstances and the better we 
identify the concerns of the communities to be served, the faster the 
adoption will be of the solutions we offer them.

Hope you are having a great day!


Patrick Durusau
Chair, V1 - Text Processing: Office and Publishing Systems Interface
Co-Editor, ISO 13250, Topic Maps -- Reference Model
Member, Text Encoding Initiative Board of Directors, 2003-2005

Topic Maps: Human, not artificial, intelligence at work!