4.8. Inner classes and enumerations

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We will illustrate both how to deal with public static inner classes and enumerations at once.

The rules to deal with them in Golo are as follows.

Inner classes are identified by their real name in the JVM, with nested classes being separated by a $ sign. Hence, Thread.State in Java is written Thread$State in Golo.
Enumerations are just normal objects. They expose each entry as a static field, and each entry is an instance of the enumeration class.

Let us consider the following example:

module sample.EnumsThreadState

import java.lang.Thread$State

function main = |args| {

  # Call the enum entry like a function
  let new = Thread$State.NEW()
  println("name=" + new: name() + ", ordinal=" + new: ordinal())

  # Walk through all enum entries
  foreach element in Thread$State.values() {
    println("name=" + element: name() + ", ordinal=" + element: ordinal())
  }
}

Running it yields the following console output:

$ golo golo --files samples/enums-thread-state.golo
name=NEW, ordinal=0
name=NEW, ordinal=0
name=RUNNABLE, ordinal=1
name=BLOCKED, ordinal=2
name=WAITING, ordinal=3
name=TIMED_WAITING, ordinal=4
name=TERMINATED, ordinal=5
$