!7

sclass Parser {

  new StringTree2 tree;

  L<S> tok(S s) { ret javaTok(s); }

  L<S> tokC(S s) { ret javaTokC(s); }

  void register(S text, O action) {

    addToStringTree(tree, tokC(text), action);

  }

  Parsing parse(S text) {

    ret nu(Parsing,

      parser := this, it := tokC(text).iterator(),

      treesInFlight := ll(new InFlight(tree)));

  }

}

sclass InFlight {

  new L history;

  StringTree2 tree;

  *() {}

  *(StringTree2 *tree) {}

  *(L *history, StringTree2 *tree) {}

}

sclass Parsing {

  Parser parser;

  Iterator<S> it;

  new L<InFlight> treesInFlight;

  void run {

    while (it.hasNext()) step();

  }

  void step {

    S token = it.next();

    for i over treesInFlight: {

      InFlight tree = treesInFlight.get(i);

      StringTree2 tree2 = tree.tree.get(token);

      if (tree2 == null) treesInFlight.remove(i--);

      else treesInFlight.set(i, new InFlight(tree.history, tree2));

    }

    actions();

  }

  void actions {

    for (StringTree2 tree : treesInFlight)

      if (tree! != null)

        runAction(tree!);

  }

  void runAction(O o) {

    print("Action! " + struct(o));

  }

}

p {

  new Parser p;

  p.register("I am here", "I-am-here");

  Parsing pp = p.parse("yo I am here");

  pp.run();

}