Overview of interfaces

Gosu supports interfaces, including full support for Java interfaces. An interface is a set of method signatures that a type must implement. An interface defines a contract that specifies the minimum set of functionality to be considered compatible. To define an interface, use the interface keyword, then the interface name, and then a set of method signatures without function bodies. The following Gosu code uses the interface keyword to define a simple interface:

package example

interface ILoadable {
  function load()
}

A class can implement the interface with the implements keyword followed by a comma-delimited list of interfaces. A class that implements an interface contains all methods in the interface, as shown in the following code:

package example

class LoadableThing implements ILoadable {

  function load() {
    print("Loading...")
  }
}