XMLification of presentation syntax

Hi,

While this ping-pong exchange has been raging on the topic of the -
by now - (in)famous, notation "foo:bar"^^rif:buzz, I have been myself
laboring on more pedestrian pursuits generating a compiler for the
presentation syntax that would at least be able to parse the syntax
of the examples given in [1] and produce the XML trees rendered as
written by you in that document.

Here is what I am not sure to understand right. Your explanation
will be most appreciated - so I can proceed and finish that thing
already!... :-) (I am very close actually - but I'd be unwise to
crow victory too soon as there may be further such snags lurking
still.)

The EBNF rules you give for this pertain to the non-terminal Const
for which you give the following rules (in [2]):

   Const          ::= '"' UNICODESTRING '"^^' SYMSPACE
   SYMSPACE       ::= UNICODESTRING

Then, you give the following (informal context-sensitive) translation
(meta-)rule for expressing this construct in XML (see [3]):

   unicodestring^^space ==> <Const type="space">unicodestring</Const>

Note that this EBNF uses two tokens '"' and '"^^' and NOT three tokens
'"', '"', and '^^', so that this begs the question of how what goes in
between '"' and '"^^' gets interpreted (especially ':').

You give examples of how this is actually used to produce the XML
encoding of the presentation syntax, such as in Example 4 of [4] :

   "cpt:purchase"^^rif:iri ==> <Const type="rif:iri">cpt:purchase</Const>

Now, I note the following points in this example:

a. cpt:purchase (without quotes) is the UNICODESTRING. By that, I
    understand that it is tokenized as a single atomic string (namely,
    the string 'cpt:purchase' where ':' is part of the string).

b. rif:iri (also without quotes) is also a UNICODESTRING, and thus
    it too is tokenized as a single atomic string.

The above makes me think that the UNICODESTRING could be anything
not containing special chars (including ':' and such that may have
other special meaning in XML). Am I right ?

My question: "Is ':' given any special meaning? In other words, is
'cpt:purchase' an XML local name, or is it that 'cpt' is the XML
namespace and 'purchase' the XML local name ?

Thanks for clarifying...

-hak

References:

[1]http://www.w3.org/2005/rules/wiki/BLD
[2]http://www.w3.org/2005/rules/wiki/BLD#EBNF_for_the_RIF-BLD_Rule_Language
[3]http://www.w3.org/2005/rules/wiki/BLD#Translation_of_the_RIF-BLD_Condition_Language
[4]http://www.w3.org/2005/rules/wiki/BLD#XML_for_the_RIF-BLD_Condition_Language
-- 
Hassan Aït-Kaci  *  ILOG, Inc. - Product Division R&D
http://koala.ilog.fr/wiki/bin/view/Main/HassanAitKaci

Received on Friday, 2 May 2008 16:38:28 UTC