In this paper we present a non-deterministic call-by-need (untyped) lambda calculus λ_nd with a constant choice and a let-syntax that models sharing. Our main result is that λ_nd has the nice operational properties of the standard lambda ...

Recent advances in compiler technology have demonstrated the benefits of using strongly typed intermediate languages to compile richly typed source languages (e.g., ML). A type-preserving compiler can use types to guide advanced optimizations and to help ...

Intensional polymorphism, the ability to dispatch to different routines based on types at run time, enables a variety of advanced implementation techniques for polymorphic languages, including tag-free garbage collection, unboxed function arguments, ...

A Hindley-Milner type system such as ML's seems to prohibit type-indexed values, i.e., functions that map a family of types to a family of values. Such functions generally perform case analysis on the input types and return values of possibly different ...

In this paper we explain how recursion operators can be used to structure and reason about program semantics within a functional language. In particular, we show how the recursion operator fold can be used to structure denotational semantics, how the ...

The paper presents a generalization of Haskell's IO monad suitable for synchronous concurrent programming. The new monad integrates the deterministic concurrency paradigm of synchronous programming with the powerful abstraction features of functional ...

Cayenne is a Haskell-like language. The main difference between Haskell and Cayenne is that Cayenne has dependent types, i.e., the result type of a function may depend on the argument value, and types of record components (which can be types or values) ...

We present a subtyping extension to the Hindley/Milner type system that is based on name inequivalence. This approach allows the subtype relation to be defined by incremental construction of polymorphic records and datatypes, in a way that subsumes the ...

We present two purely functional implementations of the computational differentiation tools -- the well known numeric (not symbolic!) techniques which permit to compute pointwise derivatives of functions defined by computer programs economically and ...

We provide a semantical framework for exact real arithmetic using linear fractional transformations on the extended real line. We present an extension of PCF with a real type which introduces an eventually breadth-first strategy for lazy evaluation of ...

The application of natural semantic specifications of lazy evaluation to areas such as usage analysis, formal profiling and abstract machine construction has shown it to be a useful formalism. This paper introduces several variants and extensions of ...

Higher-order modules are very effective in structuring large programs and defining generic, reusable software components. Unfortunately, many compilation techniques for the core languages do not work across the module boundaries. As a result, few ...

What is a good method to specify and derive imperative programs? This paper argues that a new form of functional programming fits the bill: where variable functions can be updated at specified points in their domain.Traditional algebraic specification ...

The Fudgets system is a toolkit for developing graphical applications in the lazy functional programming language Haskell. In this paper we develop an operational semantics for a subset of this system, inspired by ideas from concurrency theory. A ...