Groovy Goodness: Implementing MetaClass Methods with Same Name but Different Arguments

Using the metaClass property of a class we can add new methods or override existing methods of the class. If we want to add a new methods that have the same name, but different arguments, we can use a shortcut notation. Groovy allows us to chain multiple leftShift() (<<) methods together. String.metaClass.groovy << { Integer number -> delegate * number } << { String s -> delegate + s } << { -> del

[nobeans]

最初この辺の特性がよくわからなくて悩んだ。=で上書き(既存の同名メソッドは消える)。<<で異なるシグネチャのメソッドを追加できる。