Method Evaluate

extensions/select_optimization.cc:697–739

}

absl::Status StackMachineImpl::Evaluate(ExecutionFrame* frame) const {
  // Default empty.
  AttributeTrail attribute_trail;
  // TODO(uncreated-issue/51): add support for variable qualifiers and string literal
  // variable names.
  constexpr size_t kStackInputs = 1;

  // For now, we expect the operand to be top of stack.
  const Value& operand = frame->value_stack().Peek();

  if (operand->Is<ErrorValue>() || operand->Is<UnknownValue>()) {
    // Just forward the error which is already top of stack.
    return absl::OkStatus();
  }

  if (frame->enable_attribute_tracking()) {
    // Compute the attribute trail then check for any marked values.
    // When possible, this is computed at plan time based on the optimized
    // select arguments.
    // TODO(uncreated-issue/51): add support variable qualifiers
    attribute_trail = GetAttributeTrail(frame);
    CEL_ASSIGN_OR_RETURN(absl::optional<Value> value,
                         CheckForMarkedAttributes(*frame, attribute_trail));
    if (value.has_value()) {
      frame->value_stack().Pop(kStackInputs);
      frame->value_stack().Push(std::move(value).value(),
                                std::move(attribute_trail));
      return absl::OkStatus();
    }
  }

  if (!operand->Is<StructValue>()) {
    return absl::InvalidArgumentError(
        "Expected struct type for select optimization.");
  }

  CEL_ASSIGN_OR_RETURN(Value result,
                       impl_.ApplySelect(*frame, operand.GetStruct()));

  frame->value_stack().Pop(kStackInputs);
  frame->value_stack().Push(std::move(result), std::move(attribute_trail));
  return absl::OkStatus();
}

class RecursiveImpl : public DirectExpressionStep {
 public: