Homepage of Tom Schrijvers

Contact Information

dr. ir. Tom Schrijvers
Department of Computer Science
K.U.Leuven
Celestijnenlaan 200A (room 01.168)
3001 Heverlee
Belgium
Phone: +32 16 327544
E-mail:tom.schrijvers+www @ cs.kuleuven.be

Work

Upcoming Events

2010

FLOPS 2010: 10th International Symposium on Functional and Logic Programming, April 19-21, 2010, Sendai, Japan.
CULP 2010: 2nd Commercial Users of Logic Programming Workshop, July 21, 2010, Edinburgh, UK.

Latest News

November 2009

Haskell Type Constraints Unleashed, D. Orchard, T. Schrijvers. [draft pdf]
Let Should Not Be Generalized, D. Vytiniotis, S. Peyton Jones, T. Schrijvers. Accepted at TLDI 2010.
Monadic Constraint Programming, T. Schrijvers, P. Stuckey, P. Wadler. Published in the Journal of Functional Programming. [draft pdf, on Hackage, JFP] [Abstract] [Hide abstract]
A constraint programming system combines two essential components: a constraint solver and a search engine. The constraint solver reasons about satisfiability of conjunctions of constraints, and the search engine controls the search for solutions by iteratively exploring a disjunctive search tree defined by the constraint program. In this paper we give a monadic definition of constraint programming where the solver is defined as a monad threaded through the monadic search tree. We are then able to define search and search strategies as first class objects that can themselves be built or extended by composable search transformers. Search transformers give a powerful and unifying approach to viewing search in constraint programming, and the resulting constraint programming system is first class and extremely flexible.
A transformational approach for proving properties of the CHR constraint store, P. Pilozzi, T. Schrijvers, M. Bruynooghe. Submitted to LOPSTR 2009 post-proceedings. [draft]

October 2009

Strictness Meets Dataflow, T. Schrijvers, Alan Mycroft. [paper]

September 2009

Complete and Decidable Type Inference for GADTs, T. Schrijvers, S. Peyton Jones, M. Sulzmann, D. Vytiniotis. Presented at ICFP 2009. [draft,slides]
Monadic Constraint Programming, T. Schrijvers, joint invited talk at WLP 2009 and LPNMR 2009, September 16, 2009 in Potsdam, Germany. [slides]

August 2009

Monadic Constraint Programming with Gecode, P. Wuille, T. Schrijvers. Accepted at ModRef 2009. [pdf,project page]
Monadic Constraint Programming, T. Schrijvers, talk at AngloHaskell 2009.

July 2009

EffectiveAdvice: Overview, background and proofs, B. Oliveira, T. Schrijvers, W. Cook. [technical report]

June 2009

Monadic Constraint Programming, T. Schrijvers, seminar on June 19, 2009 at the Cambridge University Computer Laboratory, UK.
Monadic Constraint Programming, T. Schrijvers, seminar on June 15, 2009 at the University of Kent, UK.
Towards a framework for constraint-based test case generation, T. Schrijvers, F. Degrave, W. Vanhoof. Extended abstract, LOPSTR 2009.
A transformational approach for proving properties of the CHR constraint store, P. Pilozzi, T. Schrijvers, M. Bruynooghe. Extended abstract, LOPSTR 2009.

May 2009

Monadic Constraint Programming, T. Schrijvers, seminar on May 27, 2009 at the Computing Laboratory, Oxford University, UK.
Complete and Decidable Type Inference for GADTs, T. Schrijvers, seminar on May 22, 2009 at the Computing Laboratory, Oxford University, UK.
Dictionaries: Lazy or Eager Type Class Witnesses?, T. Schrijvers, seminar on May 15, 2009 at the Computer Laboratory, Cambridge University, UK. [slides]

April 2009

I am visiting the Cambridge University Computer Laboratory from April 1 until September 30.
Attributed Data for CHR Indexing, B. Sarna-Starosta, T. Schrijvers. Accepted at ICLP 2009. [draft]

March 2009

Complete and Decidable Type Inference for GADTs, T. Schrijvers, seminar on March 24, 2009 at the Foundations Group / Brouwer Institute, Nijmegen, The Netherlands. [slides]
As Time Goes By: Constraint Handling Rules -- A Survey of CHR Research from 1998 to 2007, J. Sneyers, P. Van Weert, T. Schrijvers, L. De Koninck. Accepted at TPLP (submitted: March 27, 2008). [final article]

February 2009

The Computational Power and Complexity of Constraint Handling Rules, J. Sneyers, T. Schrijvers, B. Demoen. Published in TOPLAS, 31(2), February 2009.
Constraint-based Test Generation for Pointer-based Data Structures, T. Schrijvers, F. Degrave, W. Vanhoof. [draft]

January 2009

Type Invariants for Haskell, T. Schrijvers, L.-J. Guillemette, S. Monnier. Presented at PLPV 2009. [pdf,slides] [Details] [Hide details]
Haskell's multi-parameter type classes, together with functional dependencies, allow the specification of complex type-level operations, and the recent introduction of open type families in GHC makes such type-level programming even more accessible and flexible. But type-level code is special in that its correctness is crucial to the safety of the program; so except in those cases simple enough for the type checker to see trivially that the code is correct (or harmless), type-level programs need to come with their specification and correctness proof. In this article, we propose an extension to Haskell that allows the specification of invariants for type classes and open type families, together with accompanying evidence that those invariants hold. To accommodate the open nature of type classes and type families, the evidence itself needs to be open and every subcase of the proof can be provided independently from the others.