Toward documentation of program evolution

The documentation of a program often falls behind the evolution of the program source files. When this happens it may be attractive to shift the documentation mode from updating the documentation to documenting the evolution of the program. This paper describes tools that support the documentation of program evolution. The tools are refinements of the elucidative programming tools, which in turn are inspired from literate programming tools. The version-aware elucidative programming tools are able to process a set of program source files in different versions together with unversioned documentation files. The paper introduces a set of fine grained program evolution steps, which are supported directly by the documentation tools. The automatic discovery of the fine grained program evolution steps makes up a platform for documenting coarse grained and more high-level program evolution steps. It is concluded that our approach can help revitalize older documentation, and that discovery of the fine grained program evolution steps help the programmer in documenting the evolution of the program.