code: function ConsNode(cons, children) {
      this.cons = cons;
      for(var i = 0; i < children.length; i++) {
          this[i] = children[i];
      }
      this.length = children.length;
  }
docs: Represents a constructor node
  
  Example: Add(Num("1"), Num("2")) is constucted
  using new ConsNode(new ConsNode("Num", [new StringNode("1")]),
  new ConsNode("Num", [new StringNode("2")]))
  or, more briefly:
  tree.cons("Add", [tree.cons("Num", [ast.string("1"), ast.string("2")])])