Querying distilled code changes to extract executable transformations

Reinout Stevens, Tim Christiaan Molderez, Coen De Roover

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)
65 Downloads (Pure)


Change distilling algorithms compute a sequence of fine-grained changes that, when executed in order, transform a given source AST into a given target AST. The resulting change sequences are used in the field of mining software repositories to study source code evolution. Unfortunately, detecting and specifying source code evolutions in such a change sequence is cumbersome. We therefore introduce a tool-supported approach that identifies minimal executable subsequences in a sequence of distilled changes that implement a particular evolution pattern, specified in terms of intermediate states of the AST that undergoes each change. This enables users to describe the effect of multiple changes, irrespective of their execution order, while ensuring that different change sequences that implement the same code evolution are recalled. Correspondingly, our evaluation is two-fold. We show that our approach is able to recall different implementation variants of the same source code evolution in histories of different software projects. We also evaluate the expressiveness and ease-of-use of our approach in a user study.
Original languageEnglish
Pages (from-to)491-535
Number of pages45
JournalEmpirical Software Engineering
Issue number1
Publication statusPublished - 15 Feb 2019


  • Change distilling
  • Change querying
  • Logic meta-programming

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