Lazy programs are beautiful, but they are slow because they build many thunks. Simple measurements show that most of these thunks are unnecessary: they are in fact always evaluated, or are always cheap. In this paper we describe Optimistic Evaluation ---...

By allowing the programmer to write code that can generate code at run-time, meta-programming offers a powerful approach to program construction. For instance, meta-programming can often be employed to enhance program efficiency and facilitate the ...

FreshML extends ML with elegant and practical constructs for declaring and manipulating syntactical data involving statically scoped binding operations. User-declared FreshML datatypes involving binders are concrete, in the sense that values of these ...

We present the derivation of a space efficient parser combinator library: the constructed parsers do not keep unnecessary references to the input, produce online results and efficiently handle ambiguous grammars. The underlying techniques can be applied ...

This paper presents a static type system for JAVA Virtual Machine (JVM) code that enforces an access control mechanism similar to the one found, for example, in a JAVA implementation. In addition to verifying type consistency of a given JVM code, the ...

All classical ?-terms typable with disjunctive normal forms are shown to share a common computational behavior: they implement a local exception handling mechanism whose exact workings depend on the tautology. Equivalent and more efficient control ...

We describe extensions to the Excel spreadsheet that integrate user-defined functions into the spreadsheet grid, rather than treating them as a "bolt-on". Our first objective was to bring the benefits of additional programming language features to a ...

Functional Reactive Programming (FRP) is a framework for reactive programming in a functional setting. FRP has been applied to a number of domains, such as graphical animation, graphical user interfaces, robotics, and computer vision. Recently, we have ...

Program analysis is the heart of modern compilers. Most control flow analyses are reduced to the problem of finding a fixed point in a certain transition system, and such fixed point is commonly computed through an iterative procedure that repeats ...

We present the functional language CDuce, discuss some design issues, and show its adequacy for working with XML documents. Distinctive features of CDuce are a powerful pattern matching, first class functions, overloaded functions, a very rich type ...

We propose a type system for locating the source of type errors in an applied lambda calculus with ML-style polymorphism. The system is based on discriminative sum types---known from work on soft typing---with annotation subtyping and recursive types. ...

To improve the quality of type error messages in functional programming languages,we propose four techniques which influence the behaviour of constraint-based type inference processes. These techniques take the form of externally supplied type inference ...