code: function Scope(data, affix, parent) {
    if (data !== undefined) {
      this.data = data;
    } else {
      this.data = {};
    }
    if (parent) {
      this.parent = parent;
      this.root = parent.root;
    } else {
      this.parent = undefined;
      this.root = this;
    }
    this.affix = affix || {};
    this.ready = false;
  }
docs: scope resolution for xtemplate like function in javascript but keep original data unmodified
  @author yiminghe@gmail.com