Re: Part 2: problems with 'pattern' spec

Hi Ross,

     In [3], you wrote:

[[
I found two problems, I think, with the specification of the pattern
attribute. 

1) The type of the 'value' attribute of pattern is 'anySimpleType.' [1]
   Should it not be 'string'?

2) The definition of 'atom' in the BNF for regular expressions [2]
   says 

        atom ::= Char | charClass | ( '(' regExp ')' )

   'Char' says

        Char ::= [^.\?*+()|#x5B#x5D]

    Since '()' is included in 'Char', the status of these characters
    is, strictly speaking, ambiguous w.r.t. parsing an atom.

- Roß

[1] http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#element-pattern
[2] http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#nt-atom

]]

     Regarding your second point, the caret (^) at the beginning of the 
regular expression that defines "Char" indicates that that's a 
"negCharGroup", which means roughly "match anything except these 
characters."  So parentheses are actually excluded from Char, and I 
believe there's no ambiguity in parsing "atom".

     I'll leave it for someone else to respond to your first point.

Thanks,

Henry
------------------------------------------------------------------
Henry Zongaro      XML Parsers development
IBM SWS Toronto Lab   Tie Line 969-6044;  Phone (905) 413-6044
mailto:zongaro@ca.ibm.com