Stefan Wehr

I am a software developer working for factis research, a company developing software solutions for mobile devices.

In 2010, I received my Ph.D. (Dr. rer. nat) from the Institute for Computer Science at the University of Freiburg, Germany. My research interests include functional and object-oriented programming languages.

Here are some online resources:

• Google+ Profile
• Twitter page
• Blog about functional programming (in german)

I'm the author of several open source software packages. Details can be found here.

• Stefan Wehr and Peter Thiemann
  JavaGI: The Interaction of Type Classes with Interfaces and Inheritance
  ACM Transactions on Programming Languages and Systems, 33:12:1-12:83, July 2011.
• Stefan Wehr and Peter Thiemann
  On the Decidability of Subtyping with Bounded Existential Types and Implementation Constraints
  New Generation Computing, 29:87-124, January 2011.
• Stefan Wehr
  JavaGI: A Language with Generalized Interfaces
  PhD thesis, Technische Fakultät der Albert-Ludwigs-Universität Freiburg im Breisgau, Germany, August 2010. URL: http://www.freidok.uni-freiburg.de/volltexte/7678/, URN: urn:nbn:de:bsz:25-opus-76785.
• Markus Degen, Peter Thiemann, and Stefan Wehr
  Eager and Delayed Contract Monitoring for Call-by-value and Call-by-name Evaluation
  Journal of Logic and Algebraic Programming, 79(7):515-549, October 2010.
• Stefan Wehr and Peter Thiemann
  On the Decidability of Subtyping with Bounded Existential Types
  In Proceedings of the Seventh Asian Symposium on Programming Languages and Systems. Lecture Notes in Computer Science, vol. 5904, Seoul, South Korea. SPRINGER, 2009.
• Stefan Wehr and Peter Thiemann
  JavaGI in the Battlefield: Practical Experience with Generalized Interfaces
  In Proceedings of the 8th International Conference on Generative Programming and Component Engineering (GPCE 2009). Denver, Colorado, USA. ACM, 2009.
• Markus Degen, Peter Thiemann, and Stefan Wehr
  True Lies: Lazy Contracts for Lazy Languages (Faithfulness is Better than Laziness)
  In 4. Arbeitstagung Programmiersprachen (ATPS'09). Lübeck, Germany. October 2009.
• Annette Bieniusa, Markus Degen, Phillip Heidegger, Peter Thiemann, Stefan Wehr, Martin Gasbichler, Marcus Crestani, Herbert Klaeren, Eric Knauel, and Michael Sperber
  Auf dem Weg zu einer robusten Programmierausbildung
  In Tagungsband zur 3. GI-Fachtagung Hochschuldidaktik Informatik. Potsdam, Germany. December 2008.
• Markus Degen, Peter Thiemann, and Stefan Wehr
  Contract Monitoring and Call-by-name Evaluation (extended abstract)
  In 20th Nordic Workshop on Programming Theory. Tallinn, Estonia. November 2008.
• Peter Thiemann and Stefan Wehr
  Interface Types for Haskell
  In Proceedings of the Sixth Asian Symposium on Programming Languages and Systems. Lecture Notes in Computer Science, vol. 5356, Bangalore, India. SPRINGER, 2008.
• Stefan Wehr and Manuel M. T. Chakravarty
  ML Modules and Haskell Type Classes: A Constructive Comparison
  In Proceedings of the Sixth Asian Symposium on Programming Languages and Systems. Lecture Notes in Computer Science, vol. 5356, Bangalore, India. SPRINGER, 2008.
• Annette Bieniusa, Peter Thiemann, and Stefan Wehr
  The Relation of Version Control to Concurrent Programming
  In Proceedings of the International Conference on Computer Science and Software Engineering. IEEE, 2008.
• Annette Bieniusa, Marcus Crestani, Markus Degen, Martin Gasbichler, Phillip Heidegger, Herbert Klaeren, Eric Knauel, Michael Sperber, Peter Thiemann, and Stefan Wehr
  HtDP and DMdA in the Battlefield - A Case Study in First-year Programming Instruction
  In Proceedings of the 2008 Workshop on Functional and Declarative Programming in Education. Victoria, BC, Canada. 2008.
• Stefan Wehr and Peter Thiemann
  Subtyping Existential Types
  In 10th Workshop on Formal Techniques for Java-like Programs FTfJP 2008, informal proceedings. Paphos, Cyprus. 2008.
• Stefan Wehr, Ralf Lämmel, and Peter Thiemann
  JavaGI: Generalized Interfaces for Java
  In Erik Ernst, editor, Proceedings of the European Conference on Object-Oriented Programming. Lecture Notes in Computer Science, vol. 4609, pp. 347-372, Berlin, Germany. Springer-Verlag, 2007.
• Markus Degen, Peter Thiemann, and Stefan Wehr
  Tracking Linear and Affine Resources with Java(X)
  In Erik Ernst, editor, Proceedings of the European Conference on Object-Oriented Programming. Lecture Notes in Computer Science, vol. 4609, pp. 550-574, Berlin, Germany. Springer-Verlag, 2007.
• Stefan Wehr
  ML Modules and Haskell Type Classes: A Constructive Comparison
  Master's thesis, Albert-Ludwigs-Universität, Freiburg, Germany, November 2005.

I co-organized the following courses:

• Informatik I, WS 2009/2010.
• Konzepte von Programmiersprachen, SS 2009.
• Informatik I, WS 2008/2009.
• Proseminar: Funktionale Programmierung in Haskell, WS 2008/2009
• Seminar: Type Systems, WS 2008/2009
• Softwaretechnik, SS 2008.
• Proseminar Fortgeschrittene Programmierung, WS 2007/2008.
• Informatik I, WS 2007/2008.
• Theory I, SS 2007.
• Compilerbau, WS 2006/2007.
• Praktikum Compilerbau, WS 2006/2007.
• Seminar: Objektorientierte Programmiersprachen, WS 2006/2007
• Internetprogrammierung, SS 2006.
• Seminar: Java, Grundlagen und Erweiterungen, WS2005/2006.
• Softwarepraktikum, WS 2005/2006.

I was one of the local organizers of

• ICFP 2007,
• IFL 2007, and
• Haskell Hackathon 2007 II.

I maintain a small (X)Emacs Reference (in german).

Address:	Dr. rer. nat. Stefan Wehr factis research GmbH Merzhauserstraße 177 79100 Freiburg i.Br. Germany
E-Mail:
PGP:	My public key, ID: 0x0B9F5CE4. If you are using gpg, you can import the key with the command gpg --keyserver wwwkeys.de.pgp.net --recv-keys 0B9F5CE4