!7

srecord Superposition(Cl options) {
  *(O... options) { this.options = asList(options); }
}

sclass Executable {
  void step(ProbabilisticMachine2 pm, ImmutableListWalker<S> inputWalker) {}
}

srecord Sequence(L steps) > Executable {
  O continuation;
  *(O... steps) { this.steps = asList(steps); }
  
  void step(ProbabilisticMachine2 pm, ImmutableListWalker<S> inputWalker) }
  
asclass GrammarClass {}
sclass Statement > GrammarClass {}

srecord grab(what) > Executable {
  void step(ProbabilisticMachine2 pm, ImmutableListWalker<S> inputWalker) {
  }
} // what: string or a GrammarClass

cprint {
  start-thread {
    Superposition main = Superposition(
      Sequence(
        grab("I"),
        grab("think"),
        Superposition(
          Sequence(
            grab("that"),
            grab(Statement)
          ),
          grab(Statement)
        )
      ),
    
      Sequence(
        grab("Do"),
        grab("you"),
        grab("think"),
        grab("that"),
        grab(Statement),
        grab("?")
      ),
    
      grab(Statement)
    );
    
    printIndentedStruct(main);
    
    S input = "I think that you're right";
    new ProbabilisticMachine2 pm;
    ImmutableListWalker<S> inputWalker = new(javaTokC(input));
    process(pm, inputWalker, main);
  }
  
  void process(ProbabilisticMachine2 pm, ImmutableListWalker<S> inputWalker, O code) {
    if (code cast Superposition) {
      fOr (O option : code.options)
        pm.addState(new ProbabilisticMachine2.State {
          void step {
            process(pm, inputWalker, option);
          }
        });
    } else if (code cast Executable) {
      pm.addState(new ProbabilisticMachine2.State {
        void step {
          code.step(pm, inputWalker, code);
        }
      });
    } else
      fail("Unknown code type: " + code);
  }
}