A large software system should not only be functional, but in order to give continuous value over time, the source code needs to be readable, maintainable, have expressive architecture and have low complexity. For a given programming language these goals can be achieved by programming idiomatically. Idiomatic programming means writing code in a more succinct way by using the complete expressive power of the language through language-specific features or paradigms or recurring constructs. Developers also prefer these methods for the simple reason that they are less work to implement, less error-prone, concise, and easier to understand. Many functional language features and techniques of Scala have a similar effect on coding projects.

Scala is a well-known functional language, and the problem addressed in this work is refactoring Scala source code in a way such that the transformed program is more idiomatic and conforms better to a functional way of writing programs. So far, the refactoring tool has been able to successfully identify and replace various types of control-flow constructs such as loops with up to 20 higher-order functions and common sequence methods available in Scala. It can also identify and replace various types of conditional expressions with pattern-match expressions, another well-known and efficient idiomatic feature of Scala.

At 1300+ lines of code, the tool is composed of Scala packages - each takes care of a kind of refactoring and can be directly imported into other Scala projects. It is IDE-independent, extendable, and makes adding new refactorings easy.