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For more information about DFDL, see Related Links below

Parser Development

In previous work, Talbott and others at Pacific Northwest Labs developed the Defuddle parser, which implemented an early version of the DFDL specification [6]. Subsequently, this project updated and extended the Defuddle parser [1-3].

At the time of the release of Version 1 of the DFDL Specification, we reviewed the Defuddle parser, and determined that it needed to be completed revised [4].

The Daffodil parser is a completely new implementation, based on Version 1 of the DFDL, as well as lessons learned from Defuddle [5]. The Daffodil parser is only partly implemented.  It is released “as is” in August 2011.

Semantic Extensions

While the XML Schema language is well suited for describing the layout of data (the "syntax"), interoperability and robust archiving require semantic mark up as well. This project will extend the DFDL model to support mapping to semantic web languages (the Resource Description Framework (RDF) and the Web Ontology Language (OWL)). We are exploring a two-step mechanism based on the use of the Gleaning Resource Descriptions from Dialects of Languages (GRDDL) specification http://www.w3.org/TR/grddl/ to associate XML to RDF mapping instructions, written, for example, in XSLT, with the DFDL description file [2,3].

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  1. McGrath, R.E., J. Kastner, A. Rodriguez, and J. Myers. ``Defuddle: a Tool for Format Translation and Metadata Extraction (Poster)''. Microsoft E-science Workshop (2009).
  2. McGrath, R.E., J. Kastner, A. Rodriguez, and J. Myers. ``Experiments in Data Format Interoperation Using Defuddle'', National Center for Supercomputing Applications, June, 2009, http://cetwww.ncsa.illinois.edu/publications/Data_Interoperationarchives.gov/applied-research/ncsa/11-experiments-in-data-format-interoperation-using-defuddle.pdf
  3. McGrath, R.E., J. Kastner, A. Rodriguez, and J. Myers. ``Towards a Semantic Preservation System'', National Center for Supercomputing Applications, June, 2009, http://arxiv.org/abs/0910.3152.
  4. Rodriguez, A. and R. E. McGrath, ``Some Notes of comparison between DFDL and Defuddle''. National Center for Supercomputing Applications, October, 2010.
  5. Rodriguez, Alejandro and Robert E. McGrath, ``Daffodil: A New DFDL Parser''. National Center for Supercomputing Applications, October, 2010
  6. Talbott, T. D., K. L. Schuchardt, E, G. Stephan, and J, D. Myers, ``Mapping Physical Formats to Logical Models to Extract Data and metadata: The Defuddle Parsing Engine'', International Provenance and Annotation Workshop. 2006, Springer: Heidelberg. p. 73-81.

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