[Pl-seminar] Benjamin Pierce talk at Harvard: April 19, 10:00AM

[Allyn Dimock]

Benjamin Pierce will be giving a talk at Harvard on Friday, April 19
at 10:00AM in Maxwell-Dworkin G125:

--------------------------
April 19th, 2002
10am
MD G125
Benjamin C. Pierce
University of Pennsylvania
http://www.cis.upenn.edu/~bcpierce/

Title:  NATIVE XML PROCESSING IN A STATICALLY TYPED LANGUAGE

Abstract:

The recent rush to adopt XML can be attributed in part to the hope
that the static typing provided by DTDs (or more sophisticated
mechanisms such as XML-Schema) will improve the robustness of data
exchange and processing.  However, although XML _documents_ can be
checked for conformance with DTDs, current XML processing languages
offer no way of verifying that _programs_ operating on XML structures
will always produce conforming outputs.

In previous work, we have designed and implemented a domain-specific
language for XML processing, called XDuce.  The main novelties of XDuce
are:

  1) A type system based on REGULAR EXPRESSION TYPES.  Regular
     expression types are a natural generalization of DTDs, describing
     structures in XML documents using regular expression operators
     (*, ?, |, etc.) and supporting a powerful form of subtyping.

  2) A corresponding mechanism for REGULAR EXPRESSION PATTERN MATCHING,
     which supports concise "grep-style" patterns for extracting
     information from inside structured sequences.

The lessons learned from XDuce are now being incorporated in a new
language, called Xtatic, whose design focuses on smooth integration of
these novel XML-processing features into mainstream, object-oriented
languages such as C#.  The current vision is that Xtatic will be
engineered as a lightweight extension to C#, offering native support
for regular expression types and patterns and completely interoperable
at the binary level with ordinary C# programs and APIs.

This talk describes the basic design principles of Xtatic, discusses a
few of of the fundamental technical issues in more depth, and sketches
the current state of the project.