PS grammar question

Hi Harold,

I am in the process of implementing a tokenizer for the RIF and I am
having headaches sorting out the various kinds of tokens a RIF-BLD PS
lexer should have for a quick prototype. I have a specific question:

In http://www.w3.org/TR/rif-bld/#EBNF_for_the_Rule_Language, you specified:

IRIMETA        ::= '(*' IRICONST? (Frame | 'And' '(' Frame* ')')? '*)'
Frame          ::= TERM '[' (TERM '->' TERM)* ']'
TERM           ::= IRIMETA? (Const | Var | Expr | 'External' '(' Expr ')')
Const          ::= '"' UNICODESTRING '"^^' SYMSPACE | CONSTSHORT
SYMSPACE       ::= ANGLEBRACKIRI | CURIE

where CONSTSHORT, ANGLEBRACKIRI, and CURIE are defined in:

http://www.w3.org/TR/2008/WD-rif-dtb-20080730/#sec-shortcuts-constants

by:

  ANGLEBRACKIRI ::= IRI_REF
  CURIE         ::= PNAME_LN | PNAME_NS
  CONSTSHORT    ::= ANGLEBRACKIRI         // shortcut for "..."^^rif:iri
                  | CURIE                 // shortcut for "..."^^rif:iri
                  | '"' UNICODESTRING '"' // shortcut for "..."^^xs:string
                  | NumericLiteral        // shortcut for "..."^^xs:integer,xs:decimal,xs:double
                  | '_' LocalName         // shortcut for "..."^^rif:local


However, when one looks at the example you give with meta-annotation:

> Example 4 (A RIF-BLD document containing an annotated group).

the meta-annoation PS you give for that example is:

> (* "http://sample.org"^^rif:iri pd[dc:publisher -> http://www.w3.org/
>                                    dc:date -> "2008-04-04"^^xs:date] *)

Can you please explain to me how http://www.w3.org/ can be derived as a
TERM according to the EBNF rules cited above?

Thanks.

-hak

PS/ BTW, the PS grammar's tokenizing is now complexified due to using PS
    to declare Prefix and Base pragmas not using double-quoted strings
    around the IRI's. The alternative would be to parse IRI's - which is
    beyond such a prototype's goal. In the canonical PS, all such IRI's
    are double-quoted strings which greatly simplifies the tokenizing.
    It'd be as simple and as easy to do so for the Prefix and Base pragmas.
--
Hassan Aït-Kaci  *  ILOG, Inc. - Product Division R&D
http://koala.ilog.fr/wiki/bin/view/Main/HassanAitKaci