A cornerstone of the theory of lambda-calculus is that intersection types characterise termination properties. They are a flexible tool that can be adapted to various notions of termination, and that also induces adequate denotational models. Since the seminal work of de Carvalho in 2007, it is known that multi types (i.e. non-idempotent intersection types) refine intersection types with quantitative information and a strong connection to linear logic. Typically, type derivations provide bounds for evaluation lengths, and minimal type derivations provide exact bounds. De Carvalho studied call-by-name evaluation, and Kesner used his system to show the termination equivalence of call-by-need and call-by-name. De Carvalho’s system, however, cannot provide exact bounds on call-by-need evaluation lengths. In this paper we develop a new multi type system for call-by-need. Our system produces exact bounds and induces a denotational model of call-by-need, providing the first tight quantitative semantics of call-by-need.
Tue 9 AprDisplayed time zone: Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna change
10:30 - 12:30 | |||
10:30 30mTalk | Handling polymorphic algebraic effects ESOP Link to publication | ||
11:00 30mTalk | Distributive Disjoint Polymorphism for Compositional Programming ESOP Xuan Bi Standard Chartered Bank, Ningning Xie University of Toronto, Bruno C. d. S. Oliveira The University of Hong Kong, Hong Kong, Tom Schrijvers KU Leuven Link to publication | ||
11:30 30mTalk | Types by Need ESOP Link to publication | ||
12:00 30mTalk | Verifiable certificates for predicate subtyping ESOP Link to publication |