Research into providing support for long term data in lazy functional programming systems is presented in this thesis. The motivation for this work has been to reap the benefits of integrating lazy functional programming languages and persistence. The benefits are . the programmer need not write code to support long term data since this is provided as part of the programming system . persistent data can be used in a type safe way since the programming language type system applies to data with the whole range of persistence . the benefits of lazy evaluation are extended to the full lifetime of a data value. Whilst data is reachable, any evaluation performed on the data persists. A data value changes monotonically from an unevaluated state towards a completely evaluated state over time. . interactive data intensive applications such as functional databases can be developed. These benefits are realised by the development of models for persistence in lazy functional programming systems. Tw...

A new programming system --- STAPLE (Statically Typed Applicative Persistent Language Environment) --- which integrates a lazy functional programming language and a persistent store is described. The motivation for introducing orthogonal persistence into a functional setting is given. Two models for achieving this integration are then described together with a discussion of the way laziness interacts with persistence and the benefits resulting from this interaction. In the first model, a system of persistent modules allows the programmer to create persistent values by naming them in a module. In the second model, a combination of stream I/O and a dynamic type allows functional programs to manipulate values already in the persistent store and to allow dynamically created values to become persistent. 1 1 Introduction The integration of persistence and lazy functional programming languages promises to reduce the complexity and improve the efficiency of functional programs. In addition...