LOG(ERROR) << "Unexpected non-primitive attribute value.";
      return "/* ERROR */";
  }
}

string AttrView::VariableStrLen() const {
  return Call("strlen", {VariableName()});
}

string AttrView::VariableSpanData() const {
  return Call(VariableName(), "data", {}, ".");
}

string AttrView::VariableSpanLen() const {
  return Call(VariableName(), "length", {}, ".");
}