IBM Haifa Research Lab
© 2009 IBM Corporation
Impressions from WRT @ OOPSLA 2008
The 2nd Workshop on Refactoring ToolsAt the Conference onObject Oriented Programming, Systems, Languages, and Applications,Nashville, Tennessee
Ran EttingerAdvanced Software Tools SeminarTel Aviv UniversityJune 8, 2009
IBM Haifa Research Lab
© 2009 IBM Corporation2
WRT: Implementing Refactorings in IntelliJ IDEA
By Dmitry Jemerov of JetBrains
“IntelliJ IDEA was one of the first Java IDEs to cross the Refactoring Rubicon”
Extract Method Object
– Instead of rejecting an Extract Method refactoring, when two or more variables must be returned
Change the type in a variable’s declaration
Looking to more languages (e.g., Ruby)
– Ad hoc support for each new language
General mechanism for (user-specified) structural search + rewriting
– Somewhat similar to Project Jackpot (NetBeans)
– Towards a domain specific language for refactoring tools
Some support for refactoring code with syntax errors
IBM Haifa Research Lab
© 2009 IBM Corporation3
WRT: Designing Refactoring Tools for Developers
DevExpress: Dustin Campbell (moved to Microsoft) and Mark Miller
Barriers between programmers and refactoring tools
– Discoverability: Provide a context menu with available transformations
– Lack of trust or lack of familiarity: Preview hinting – no commitment on the side of the programmer
– Productivity: one keyboard shortcut for all refactorings (no mouse); no modal dialogs – instead, all user input is entered on the context menu and inside the code editor
Animated reversal of parameters
Reversal of conditional (then and else)
Replace result temp with return statements
Some 150 micro-refactorings
Basic support for C++ (not so successful)
IBM Haifa Research Lab
© 2009 IBM Corporation4
WRT: Analyzing Tool Usage
By Joshua Kerievsky of IndustrialLogic
– Author of Refactoring to Patterns
No longer believes in printed books
Online albums including recorded sessions of refactorings
Online labs with refactoring exercises
– Let the student program
– Track behavior through recording refactoring history (tool in Eclipse)
– Check good practices: frequent testing, effective usage of tools
– Show code before and after
– Test-Driven Development (TDD) labs too
Refactoring rash
IBM Haifa Research Lab
© 2009 IBM Corporation5
WRT: Gathering Refactoring Data: a Comparison of Four Methods
By Emerson Murphy-Hill, Andrew P. Black, Danny Dig, and Chris Parnin
– Followed by ICSE09 best paper How We Refactor, and How We Know It
Method 1: Mining the Commit Log
Method 2: Analyzing Code Histories
Method 3: Observing Programmers
Method 4: Logging Refactoring Tool Use
IBM Haifa Research Lab
© 2009 IBM Corporation6
WRT: Refactoring is not (yet) about transformation
By Torbjörn Ekman, Max Schäfer, and Mathieu Verbaere
Refactoring = Analysis + Transformation
Analysis is hard: Bugs in all tools!
Integration with a compiler, to gain correctness, reusability and extensibility
– A refactoring engine is based on JastAddJ
Hopefully… Refactoring can be just about transformation!
IBM Haifa Research Lab
© 2009 IBM Corporation7
WRT: Refactoring a Language for Parallel Computational Chemistry
By Beverly A. Sanders, Erik Deumens, Victor Lotrich, and Mark Ponton
Refactor for performance (parallelism) while preserving correctness, not necessarily behavior!
Users are chemical scientists (more than they are programmers)
Merge loops
Exchange (nested) loops
Eliminate redundant matrix transposes
IMP-based tool (in Eclipse) for a language called SIAL
IBM Haifa Research Lab
© 2009 IBM Corporation8
WRT: Refactoring Code to Use Concurrent Library Utilities
By Danny Dig, John Marrero, and Michael D. Ernst
Refactoring for thread safety and scalability (multicore)
Java 7
Replace int with AtomicInteger
Replace HashMap with ConcurrentHashMap
Naive usage of syncronized too expensive (performance overhead)
Tool called Concurrencer
Require data-flow analysis; side effects too
Future: replace an array with a concurrent array (Java 7)
IBM Haifa Research Lab
© 2009 IBM Corporation9
WRT: Some more…
Tool Support for Refactoring Functional Programs by Huiqing Li and Simon Thompson
– Haskell, Erlang
Practical Refactoring-Based Framework Upgrade by Ilie Savga, Michael Rudolf, Sebastian Götz, and Uwe Aßmann (appeared in the co-located Conference on Generative Programming and Component Engineering – GPCE)
– Refactorings comprise 75-97% of application-breaking API changes
– Refactoring treated as a formal spec of syntactic changes
– Comebacks: Refactoring Inverses on Adapters• A comeback is a refactoring transforming adapters to compensate for a framework
refactoring. (They consider the addition of functionality also a refactoring!)
– Introduce an adaptation layer between frameworks and plugins
Re-Approaching the Refactoring Rubicon by Aharon Abadi, Ran Ettinger, and Yishai Feldman
IBM Haifa Research Lab
© 2009 IBM Corporation10
OOPSLA Essay: Designed as Designer
By Richard P. Gabriel
– “Conceptual integrity arises not (simply) from one mind or from a small number of agreeing resonant minds, but from sometimes hidden co-authors and the thing designed itself.”
First to the market myth is false
– Counterexamples: Gillete, Pampers
Fred Brooks is wrong (in his OOPSLA 2007 Keynote)
– Good design is rarely due to one (or at most two) designers• Many other (people) contribute• Even the thing being designed
– In poetry, painting, architecture (Brunelleschi’s dome of Florence), language design (Lisp, Scheme, Actors and Closures), academic research, and software too
“There’s something about our culture that seems to love heroes, that looks for the genius who’s solved it all, that seems to need to believe the first to market—the best inventor—reaps justly deserved rewards.”
IBM Haifa Research Lab
© 2009 IBM Corporation11
OOPSLA: Practitioner Reports
Performance Pitfalls in Large-Scale Java Applications Translated from COBOL
– Toshio Suganuma, Toshiaki Yasue, Tamiya Onodera, and Toshio Nakatani (IBM Tokyo Research Laboratory)
Retaining Comments when Refactoring Code
– Prof. Peter Sommerlad, Guido Zgraggen, Thomas Corbat, and Lukas Felber (IFS Institute for Software at HSR Rapperswil)
– AST is too abstract for refactoring tools!
– Removing comments is a valid Refactoring
– “Σ value(comment) < 0” (Alan Kelly)
IBM Haifa Research Lab
© 2009 IBM Corporation12
OOPSLA Demos
Refactoring Support for the Groovy-Eclipse Plug-in
– Martin Kempf, Reto Kleeb, Michael Klenk, Peter Sommerlad (IFS Institute for Software at HSR Rapperswil)
– “This article presents our refactoring plug-in for the Groovy-Eclipse Plug-in. Refactoring is a very important technique for every software engineer to ensure the healthiness of his code and a cornerstone of agile software development. In our project we introduce refactoring support for Groovy-Eclipse, with six automated refactorings as well as a source code formatter. Since Java and Groovy are that closely related we also analyzed and documented the options to introduce crosslanguage refactorings between Java and Groovy.”
Axiom-Based Testing for C++
– Anya Helene Bagge, Valentin David, and Magne Haveraaen
– “Axioms, known from program specification, allow program functionality to be described as rules or equations. The draft C++0x standard introduces axioms as part of the new concept feature. We will demonstrate a tool that uses these features for automated unit testing.”
IBM Haifa Research Lab
© 2009 IBM Corporation13
OOPSLA: Some highlights from the technical program
Sound and Extensible Renaming for Java
– Max Schäfer, Torbjörn Ekman, and Oege de Moor (Oxford)
The VISITOR Pattern as a Reusable, Generic, Type-Safe Component
– Bruno Oliveira, Meng Wang, and Jeremy Gibbons (Oxford)
Whiteoak: Introducing Structural Typing into Java
– Yossi Gil and Itay Maman (Technion)
QVM: An Efficient Runtime for Detecting Defects in Deployed Systems
– Matthew Arnold, Martin Vechev, and Eran Yahav (IBM Research)