[xsl] Context node versus current streaming position

["Costello, Roger L." <costello@xxxxxxxxx>]

Hi Folks,

I learned something neat from Michael Kay.

I learned that context node and current streaming position are not always the
same.

Suppose the XSLT processor is streaming through an input document and has
arrived at element N. The <N> element  is the current streaming position.

Now suppose the XSLT program instructs the XSLT processor: from your current
streaming position climb the XML tree and return the name of each ancestor
element:

	<xsl:for-each select="ancestor::*">
	    <xsl:value-of select="name(.)" />
	</xsl:for-each>

The context position changes with each iteration of the for-each statement.
But the current streaming position remains the same.

This is a key concept!

/Roger