Reynolds's defunctionalization technique is a whole-program transformation from higher-
order to first-order functional programs. We study practical applications of this transformation …

While type soundness proofs are taught in every graduate PL class, the gap between
realistic languages and what is accessible to formal proofs is large. In the case of Scala, it …

Scala's type system unifies aspects of ML modules, object-oriented, and functional
programming. The Dependent Object Types (DOT) family of calculi has been proposed as a …

It is well-known that many environment-based abstract machines can be seen as strategies
in lambda calculi with explicit substitutions (ES). Recently, graphical syntaxes and linear …

Proposed originally by Plotkin and Pretnar, algebraic effects and their handlers are a
leading-edge approach to computational effects: exceptions, mutable state, nondeterminism …

The evaluation function of a reduction semantics (ie, a small-step operational semantics with
an explicit representation of the reduction context) is canonically defined as the transitive …

Whether the number of β-steps in the λ-calculus can be taken as a reasonable time cost
model (that is, polynomially related to the one of Turing machines) is a delicate problem …

Effect handlers are a modern and increasingly popular approach to structuring
computational effects in functional programming languages. However, while their traditional …

An old and celebrated analogy says that writing programs is like proving theorems. This
analogy has been productive in both directions, but in particular has demonstrated …

This document illustrates how functional implementations of formal semantics (structural
operational semantics, reduction semantics, small-step and big-step abstract machines …