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.parser;

import org.jruby.lexer.yacc.RubyLexer;

public interface ParserState {
    public Object execute(ParserSupport support, RubyLexer lexer, Object yyVal, Object[] yyVals, int yyTop);
}