[Bug 24528] Streamability of xsl:number and from and count patterns


--- Comment #4 from Michael Kay <mike@saxonica.com> ---
Unfortunately we have introduced a new complication in the form of streamable
functions: the "from" and "count" patterns can now contain a variable reference
to the streaming parameter of a streamable function. I have proposed in email
[1] that when such a reference appears in a higher-order operand then it should
be free-ranging/roaming. The constructs therefore need to be included in the
analysis so that this situation is detected. The problem of references to
grouping variables has disappeared, of course, and there is an explicit rule
that current-group() cannot be used in a pattern.

I propose to change the Note to:

In practice the rules depend very little on the from and count patterns. This
is because when the instruction is applied to a streamed node, the instruction
will be free-ranging regardless of these patterns; while if it is applied to a
grounded node or atomic value, the instruction will normally be motionless
regardless of the values of these patterns. The pattern does matter, however,
if it contains a variable reference bound to the streaming parameter of a
function that is declared streamable; because such a reference occurs within a
higher-order operand, its presence automatically makes the variable reference
free-ranging and therefore means that the function as a whole is not guaranteed

[1] https://lists.w3.org/Archives/Member/w3c-xsl-wg/2014May/0023.html

You are receiving this mail because:
You are the QA Contact for the bug.

Received on Thursday, 15 May 2014 13:53:12 UTC