An implementation of XPath 3.0 metamodel (http://www.w3.org/TR/xpath-30/).

The project is based on https://github.com/AresEkb/EMFTextXPath2 It doesn't implement XPath 3.0 recommendation fully yet.

Test suite based on the specification:

fn:doc(fn:document-uri($Nq)),
($x div $y) + xs:decimal($z),
fn:error(xs:QName("app:err057"), "Unexpected value", fn:string($v)),
some $x in $expr1 satisfies $x = 47,
//product[id = 47],
if (doc-available('abc.xml')) then doc('abc.xml') else (),
$N[@x castable as xs:date][xs:date(@x) gt xs:date("2000-01-01")],
$N[if (@x castable as xs:date)
   then xs:date(@x) gt xs:date("2000-01-01")
   else false()],
fn:collection("http://example.org")//customer,
xs:integer("12"),
9 cast as hatsize,
fn:doc("bib.xml")/books/book[fn:count(./author)>1],
(1 to 100)[. mod 5 eq 0],
my:three-argument-function(1, 2, 3),
my:two-argument-function((1, 2), 3),
my:two-argument-function(1, ()),
my:one-argument-function((1, 2, 3)),
my:one-argument-function(( )),
my:zero-argument-function( ),
child::div1/child::para,
/*,
/ *,
/*5,
/ * 5,
(/) * 5,
4 + / * 5,
4 + (/) * 5,
4 + /,
attribute::abc:href,
child::*,
*:NCName,
attribute(*, xs:decimal),
document-node(element(book)),
child::chapter[2],
descendant::toy[attribute::color = "red"],
child::employee[secretary][assistant],
(ancestor::*)[1],
child::para[fn:position() = fn:last()-1],
following-sibling::chapter[fn:position() = 1],
/child::book/child::chapter[fn:position() = 5]/child::section[fn:position() = 2],
child::*[self::chapter or self::appendix][fn:position() = fn:last()],
(10, 1, 2, 3, 4),
(10, 1 to 4),
(1 to 100)[. mod 5 eq 0],
$orders[fn:position() = (5 to 9)],
$book/(chapter | appendix)[fn:last()],
fn:doc("zoo.xml")/fn:id('tiger'),
$seq1 union $seq2,
($arg1 div $arg2) cast as xs:integer?,
$emp/hiredate - $emp/birthdate,
$unit-price - $unit-discount,
-$bellcost + $whistlecost,
-($bellcost + $whistlecost),
$book1/author eq "Kennedy",
fn:QName("http://example.com/ns1", "this:color")
   eq fn:QName("http://example.com/ns1", "that:color"),
(1, 2) = (2, 3),
/books/book[isbn="1558604820"] is /books/book[call="QA76.9 C3845"],
/transactions/purchase[parcel="28-451"] 
   << /transactions/sale[parcel="33-870"],
1 eq 1 and 2 eq 2,
for $x in X, $y in Y return $x + $y,
for $a in fn:distinct-values(book/author)
return (book/author[. = $a][1], book[author = $a]/title),
for $i in (10, 20),
    $j in (1, 2)
return ($i + $j),
for $x in $z, $y in f($x)
return g($x, $y),
fn:sum(for $i in order-item return @price *
@qty),
if ($widget1/unit-cost < $widget2/unit-cost) 
  then $widget1
  else $widget2,
every $part in /parts/part satisfies $part/@discounted,
some $emp in /emps/employee satisfies 
     ($emp/bonus > 0.25 * $emp/salary),
some $x in (1, 2, 3), $y in (2, 3, 4) 
     satisfies $x + $y = 4,
. instance of element(),
if ($x castable as hatsize) 
   then $x cast as hatsize 
   else if ($x castable as IQ) 
   then $x cast as IQ 
   else $x cast as xs:string,
xs:decimal($floatvalue * 0.2E-5),
$myaddress treat as element(*, USAddress)

Copyright (c) 2013, 2015 Denis Nikiforov.
All rights reserved. This program and the accompanying materials
are made available under the terms of the Eclipse Public License v1.0
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/epl-v10.html

Contributors:
   Denis Nikiforov - initial API and implementation