We introduce System FC, which extends System F with support for non-syntactic type
equality. There are two main extensions:(i) explicit witnesses for type equalities, and (ii) …

Classical phantom types are datatypes in which type constraints are expressed using type
variables that do not appear in the datatype cases themselves. They can be used to embed …

A heterogeneous collection is a datatype that is capable of storing data of different types,
while providing operations for look-up, update, iteration, and others. There are various kinds …

Design patterns are reusable abstractions in object-oriented software. However, using
current mainstream programming languages, these elements can only be expressed extra …

Haskell programmers have been experimenting with dependent types for at least a decade,
using clever encodings that push the limits of the Haskell type system. However, the …

The'Scrap your boilerplate'approach to generic programming allows the programmer to write
generic functions that can traverse arbitrary data structures, and yet have type-specific …

Modularity is a key concern in programming. However, programming languages remain
limited in terms of modularity and extensibility. Small canonical problems, such as the …

Delimited continuations are more expressive than traditional abortive continuations and they
apparently require a framework beyond traditional continuation-passing style (CPS). We …

A session type is an abstraction of a set of sequences of heterogeneous values sent and
received over a communication channel. Session types can be used for specifying stream …

Reynolds' theory of relational parametricity captures the invariance of polymorphically typed
programs under change of data representation. Reynolds' original work exploited the typing …