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Rio: RDF I/O package 0.96 released

From: Arjohn Kampman <arjohn.kampman@aidministrator.nl>
Date: Fri, 22 Aug 2003 16:16:49 +0200
Message-ID: <3F4625D1.1090303@aidministrator.nl>
To: www-rdf-interest@w3.org

Dear all,

We (the Sesame developers) just released the first seperate release of
Sesame's RDF parsers and -writers. The package has been baptized "Rio",
as in "RDF I/O". Rio contains fast and compact parsers for RDF/XML
and N-Triples as well as writers for RDF/XML, N-Triples and
Notation3. Rio is implemented in Java.

The entire package (rio.jar) weighs just 66 kB. The RDF/XML
parser needs a SAX2-compliant XML parser to run. These are freely
available on the net (e.g. at http://xml.apache.org/xerces2-j/)
and JDK 1.4 even includes one by default.

The Rio package can be download from the Sesame SourceForge site

More information about Rio can be found in the 'parser.txt' file,
which is included in the downloadable archive, but which is also
included below.

Regards and have a good weekend,

Arjohn Kampman

About the Rio ("RDF I/O") package

The Sesame project has developed a suite of parsers and writers
for RDF-related document "standards". Currently, it contains
parsers for XML-encoded RDF (i.e. the official RDF format,
RDF/XML for short) and N-Triples. Writers exist for XML-encoded
RDF, N-Triples and Notation 3 (a.k.a. N3).

The parsers and writers for RDF/XML and N-Triples adhere to the
specs that were released in January 2003, which can be found at
<http://www.w3.org/RDF/>. There is no real specification for
Notation 3/N3, but the output generated by the N3 writer should
be compatible with other N3 tools.

Yet another RDF parser?

Yes. The main reasons for this were:
    1) We were unsatisfied with the speed and/or conformance of
       available (Java) RDF parsers.
    2) We had already completed a substantial part of the
      (RDF/XML) parser as an "exercise" to learn about the
      details of the RDF/XML spec, which we performed in December

For us, these were sufficient reasons to finish the work and
produce our own suite of parsers and writers for RDF. The
resulting parsers and writers are quite fast when compared to
other (Java-)implementations.

Using the Rio package

The Rio package can be found in package nl.aidministrator.rdf.io.
The parser for RDF/XML requires a SAX2-compliant XML parser such as
Xerces (see <http://xml.apache.org/>). The Javadoc documentation for
the Rio package contains documentation on how to use it. Please check
this documentation for more information.

Compatibility issues

We have tested the RDF/XML parser thoroughly with the approved
test cases that are available from the W3C website
(<http://www.w3.org/TR/rdf-testcases/>).  The positive test cases
from this site are test cases with correct RDF that should generate
specific sets of RDF statements. The RDF/XML parser has been tested
succesfully with all of these.

The negative test cases from this site are test cases which contain
incorrect RDF that should result in an error reported by the RDF/XML
parser. The RDF/XML parser has been tested succussfully with
all-but-three of these test cases. The failed test cases concern the
character encoding of literals and URIs. According to the specs, URIs
and literals should be in Normal Form C [NFC], but our parser does
not check for this.

[NFC] http://www.unicode.org/unicode/reports/tr15/

Bugs, comments, other feedback

Please e-mail any bugs, comments or other feedback to
sesame-devel@lists.sourceforge.net. Your feedback is highly

The Sesame development team

aidministrator nederland b.v.  - http://www.aidministrator.nl/
prinses julianaplein 14-b, 3817 cs amersfoort, the netherlands
tel. +31-(0)33-4659987  fax. +31-(0)33-4659987
Received on Saturday, 23 August 2003 09:32:18 UTC

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