Structurally Heterogeneous Source Code Examples from Unstructured Knowledge Sources

Software developers rarely write code from scratch. With the existence of Wikipedia, discussion forums, books and blogs, it is hard to imagine a software developer not looking up these sites for sample code while building any non-trivial software system. While researchers have proposed approaches to retrieve relevant posts and code snippets, the need for finding variant implementations of functionally similar code snippets has been ignored. In this work, we propose an approach to automatically create a repository of structurally heterogeneous but functionally similar source code examples from unstructured sources. We evaluate the approach on stackoverflow1, a discussion forum that has approximately 19 million posts. The results of our evaluation indicates that the approach extracts structurally different snippets with a precision of 83%. A repository of such heterogeneous source code examples will be useful to programmers in learning different implementation strategies and for researchers working on problems such as program comprehension, semantic clones and code search.