- From: Kay, Michael <Michael.Kay@softwareag.com>
- Date: Thu, 3 Jan 2002 17:16:43 +0100
- To: "'James Swift'" <Swift@altova.com>, www-xpath-comments@w3.org
> Since parentheses may be used for grouping this is obviously allowed,
>
> /foo/bar[ ( fish or cow ) and dog ]
>
> however am I correct in assuming that the following example
> supplied in the spec is not allowed according to the grammar?
>
> (preceding::foo)[1]
>
> I do understand what it means etc. I just can't work out how
> (Expr)Predicate is allowed.
This expression is allowed, I think. An Expr can be a StepExpr, which can be
a GeneralStep; a GeneralStep is a PrimaryExpr followed by a StepQualifiers;
a parenthesized expression is a PrimaryExpr, and "[1]" is a StepQualifiers.
> It's not allowed to have '(' or ')' ina Step either.
Again, a StepExpr can be a GeneralStep which can be a Primary.
Mike Kay
Received on Thursday, 3 January 2002 11:16:47 UTC