Hello XQuery ... Goodbye XSLT?

["Roger L. Costello" <costello@mitre.org>]

Hi Folks,

 

From my examinations, it would appear that XQuery is a superset of XSLT.  I wonder about the future of XSLT?

 

Consider this:

 

1. XPath 2.0 replicates nearly all the functionality of XSLT.  Here are some examples:

 

(a) Looping (iteration):

 

      XSLT provides the <xsl:for-each select="..."/> element for looping

 

      XPath 2.0 provides an equivalent capability: for $i in ... return ...

 

(b) Conditional tests

 

      XSLT provides the <xsl:if test="..."> element for conditional tests

 

      XPath 2.0 provides an equivalent capability: if (...) then ... else ...

 

(c) Accessing multiple data sources

 

      XSLT provides the document(...) function to access other data sources

 

      XPath 2.0 provides an equivalent capability: the doc(...) function

 

Thus, we see that there is a good bit of redundancy in the XSLT/XPath 2.0.  [Such redundancy increases the size and complexity of the language, without additional functionality.]

 

2. XQuery uses (hosts) XPath 2.0, and adds additional functionality.  That is, XQuery = XPath 2.0 + more functionality.  Although I have not made an exhaustive comparison, it would appear that the functionality that XQuery provides is a superset of that provided by XSLT. 

 

Is the intent of the W3 to deprecate (i.e., eliminate) XSLT once XQuery is released?  /Roger