Transformation and Analysis of Functional Programs

This thesis describes techniques for transforming and analysing functional programs. We operate on a core language, to which Haskell programs can be reduced. We present a range of techniques, all of which have been implemented and evaluated. We make programs shorter by defining a library which abstracts over common data traversal patterns, removing boilerplate code. This library only supports traversals having value-specific behaviour for one type, allowing a simpler programming model. Our library allows concise expression of traversals with competitive performance. We make programs faster by applying a variant of supercompilation. As a result of practical experiments, we have identified modifications to the standard supercompilation techniques – particularly with respect to let bindings and the generalisation technique. We make programs safer by automatically checking for potential patternmatch errors. We define a transformation that takes a higher-order program