Type-Safe Generic Differencing of Mutually Recursive Families

Abstract

The UNIX diff tool, which computes the differences between two files in terms of a set of copied lines, is widely used in software version control. The fixed lines-of-code granularity, however, is sometimes too coarse and obscures simple changes, i.e., renaming a single parameter triggers the whole line to be seen as changed. This dissertation explores techniques and implementations for detecting and reasoning about changes in a finer granularity.