Source code file written in the Scala (Scalable language) programming language; uses an object-oriented and functional approach with support of higher-order functions and nesting of function definitions.

Scala is a Java-like programming language that can call Java methods, inherit from Java classes, implement Java interfaces, and create Java objects. The source code can be compiled to Java byte code that can run on a Java virtual machine. The language also supports optional parameters, raw strings, named parameters, operator overloading. NOTE: Development of the Scala language began in 2001 in the programming methods laboratory at École polytechnique fédérale de Lausanne (EPFL) in Switzerland.