ARQ is a query processor for Jena that implements SPARQL.

Announcing ARQ 1.4 - this is an upgrade to the version distributed
with Jena 2.4.  This distribution of ARQ includes an updated
copy of jena.jar.

In this release:

    Support for xsd:date for FILTER and ORDER BY
    JRuby-ARQ library
    Property functions improvements, including list arguments
    Improved extensibility framework
    Internal changes to make ARQ reflect the structure of SPARQL
    More library functions
    New internal serialization format

Download:
    http://prdownloads.sourceforge.net/jena/ARQ-1.4.zip

Home page:
	http://jena.sourceforge.net/ARQ/

ARQ is also available via anonymous CVS:

cvs -z3 -d:pserver:anonymous@cvs.sourceforge.net:/cvsroot/jena co ARQ

SPARQL is described in:
  http://www.w3.org/TR/rdf-sparql-query/


Notes
-----

Property functions improvements:
  Added support for lists as arguments to property function.
  New package and interface especially for property functions.

Added a new serialization format: "prefix" (with a parser and serializer)
which gives the clearest picture of the SPARQL abstract syntax tree.

Internal changes 
  + class renaming and structuring to be more SPARQL-like
  + expression evaluation is completly functional evaluation
    expect for for required special forms.
  + Support in the default query engine to make writing engines that access
    specialised stores, whether RDF or non-RDF, much easier.  Less
    unnecessary details of the query engine need be handled.  Transformation
    framework for rewriting queries and inserting adapters to other data
    storage systems.
    Example in src-examples/arq/examples/ext/MyQueryEngine.java

More details in ChangeLog.txt

Status
------

The implementation of SPARQL is complete and meets the SPARQL last call
specification.

Services
--------

SPARQL validator: 
http://www.sparql.org/validator.html

SPARQL processor:
http://www.sparql.org/sparql.html

JAR changes
-----------

arq.jar ==> arq.jar and arq-extr.jar
  arq.jar has been split into 
    arq.jar - the com.hp.hpl.jena.query package tree without tests and
              test support code.
    arq-extra.jar - test code, examples, command line tools.

ARQ requires the version of jena.jar included in the download or a later
version from Jena CVS.

common-logging.jar ==> commons-logging-1.1.jar
  Upgraded to Apache Commons Logging 1.1
  v1.0.4 common-logging.jar also works

wstx-asl-2.8.jar ==> wstx-asl-3.0.0.jar
  Upgraded to wstx-asl-3.0.0.jar for StAX parsing.

API Changes
-----------

This release is primary internal changes to bring the internal
structure and naming into line with the current SPARQL specification
and to imporve extensibility.

Applications directly manipulating the Java abstract syntax tree will
be affected.

There is a new class ElementBasicGraphPattern; triple
patterns are collected into basic graph patterns (adapter method
exist in ElementGroup to ease migration).

The examples in src-example/ have been updated to new structures.
(examples are also now part of the built and test process.)

Removal of Query.getQueryBlock / setQueryBlock
  The top of a query pattern is no longer an ElementBlock.
  Just set the pattern to any Element: use Query.setQueryPattern

Deprecated opeations will be removed after this release.

Support and Questions
---------------------

Comments and questions about ARQ to the Jena mailing list 
    jena-dev@groups.yahoo.com

General questions and comments on SPARQL to jena-dev or
    public-sparql-dev@w3.org
    
Formal comments specific to the SPARQL query language,
protocol or result set docuemnts to:
	public-rdf-dawg-comments@w3.org