Vous pouvez vous abonner à nos annonces de séminaires http://gallium.inria.fr/seminaires/ S E M I N A I R E __ / _` _ / / o / ) __) / / / / / /\/| (___/ (_/ (_ (_ / (__/ / | I N R I A - Paris 2 rue Simone Iff (ou: 41 rue du Charolais) Salle Lions 1, bâtiment C VENDREDI 17 juin, 15h00 ----------- Ohad Kammar ----------- University of Oxford ================================================================= No value restriction is needed for algebraic effects and handlers ================================================================= We present a straightforward, sound Hindley-Milner polymorphic type system for algebraic effects and handlers in a call-by-value calculus, which allows type variable generalisation of arbitrary computations, not just values. This result is surprising. On the one hand, the soundness of unrestricted call-by-value Hindley-Milner polymorphism is known to fail in the presence of computational effects such as reference cells and continuations. On the other hand, many programming examples can be recast to use effect handlers instead of these effects. Analysing the expressive power of effect handlers with respect to state effects, we claim handlers cannot express reference cells, and show they can simulate dynamically scoped state. Time permitting, we will discuss the denotational soundness theorem that led to this work. Joint work with Sean Moss and Matija Pretnar.