Evaluatable XPath. ( XPath extensions ).

I'm writing somehow expanded  XPath engine. 
One of the extensions I want to have is ability to calculate parts 
of Xpath on the fly. I see it like:

/some/{$calculated}/node

The idea is that when some part of Xpath expression is placed
inside { and } - that part get's evaluated to string.

This allows writing things like:

<cfg>
<eng> <text> English text </text> </eng>
<ru> <text> Russian text </text> </ru>
</cfg>

<xsl:value-of  select  ="/cfg/{$lang}/text"/>

That'll be evaluated into 

<xsl:value-of  select  ="/cfg/eng/text"/>

or 

<xsl:value-of  select  ="/cfg/ru/text"/>

depending on the value of variable $lang.

E t.c. 

1. Is there any chance we'll get evaluatable XPath in W3C 'standard'  ?

2. Is there some drawback which I don't see ?

3. In case (2) is true - could somebody suggest a better syntax for this extension?

Many thanks.

Rgds.Paul.

PS. 

In fact, those who are used to perl should be familiar with things like this 
( I still think  that XPath is a just a reincarnation of regular expressions, so 
inheriting some successful techniques from perl  looks reasonable to me.).




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