https://github.com/jruby/jruby/jruby-core: JRuby is the effort to recreate the Ruby (https://www.ruby-lang.org) interpreter in Java. (JRuby)
  • headius
  • enebo
  • wmeissner
  • BanzaiMan
  • mkristian 
package org.jruby.ir;

// Just an int-wrapper so that we can modify the counter in-place
// (unlike an Integer which is immutable)
public class Counter {
    public long count = 0;
}