[TYPES] Paper on Expression Problem

[Martin Odersky]

We would like to announce the availability of a paper
        
       "Independently Extensible Solutions to the Expression Problem"
                     Matthias Zenger, Martin Odersky

Abstract:
 
  The expression problem is fundamental for the development of
extensible software.  Many (partial) solutions to this problem have
been proposed in the past.  None of these approaches solves the
problem of using different, independent extensions jointly.  This
paper proposes solutions to the expression problem that make it
possible to combine independent extensions in a flexible, modular, and
type-safe way.  The solutions, formulated in the programming language
Scala, are affected with only a small implementation overhead and are
easy to implement by hand.

A technical report is available at
http://scala.epfl.ch/docu/related.html
Comments and suggestions are most welcome.

-- Martin Odersky and Matthias Zenger