- From: Kay, Michael <Michael.Kay@softwareag.com>
- Date: Mon, 30 Sep 2002 17:49:28 +0200
- To: Max Froumentin <mf@w3.org>, public-qt-comments@w3.org
As you note, "1,2,3" is not an expression unless you put parentheses around it. In a sense, ExprSequence is a generalization of an Expression: every Expr is an ExprSequence. XQuery allows an ExprSequence in certain contexts, for example the content between "{}" in an element constructor. We could decide in XSLT to allow an ExprSequence rather than an Expr as the top-level construct. I think the only reason that 1,2,3 is not a valid expression is that it wouldn't make sense to write it as an argument to a function call, or in certain other contexts such as E1 in "for $e1 in E1, $e2 in E2 return E3" Perhaps it would make more sense to rename the productions: Expr := ExprSequence ExprSequence := OrExpr (',' OrExpr)... ArgumentList := OrExpr (',' OrExpr)... Michael Kay (I'm not sure why you raised this on the public list...) > -----Original Message----- > From: Max Froumentin [mailto:mf@w3.org] > Sent: 30 September 2002 16:24 > To: public-qt-comments@w3.org > Subject: XSLT: sequences in Exprs and notation, XPath: FLWR? > > > > Hi, > > I was checking whether I was allowed to write <xsl:value-of > select="1,2,3"/>, after Saxon7.2 rejected it (while allowing > "(1,2,3)"). I read the xslt spec, and found that in value-of > the content of the select attribute is an 'expression', > corresponding to the XPath production Expr, which does not > include ExprSequence (which would have allowed "a,b,c"). Did > I miss something or is there an error in the spec, or saxon, or both? > > While looking for an answer I found that > "sequence-expression" and "node-sequence-expressions", found > in the element syntax notation do not seem to be defined in the draft. > > And Issues 318 and 233 have locus 'xpath' and are about FLWR > expressions, which are not in XPath. > > Max. >
Received on Monday, 30 September 2002 11:49:53 UTC