Method Evaluate

eval/eval/comprehension_step.cc:447–484

}  // namespace

absl::Status ComprehensionInitStep::Evaluate(ExecutionFrame* frame) const {
  if (!frame->value_stack().HasEnough(1)) {
    return absl::Status(absl::StatusCode::kInternal, "Value stack underflow");
  }

  const Value& top = frame->value_stack().Peek();
  if (top.IsError() || top.IsUnknown()) {
    return frame->JumpTo(error_jump_offset_);
  }

  if (frame->enable_unknowns() && top.IsMap()) {
    const AttributeTrail& top_attr = frame->value_stack().PeekAttribute();
    if (frame->attribute_utility().CheckForUnknownPartial(top_attr)) {
      frame->value_stack().PopAndPush(
          frame->attribute_utility().CreateUnknownSet(top_attr.attribute()));
      return frame->JumpTo(error_jump_offset_);
    }
  }

  switch (top.kind()) {
    case ValueKind::kList: {
      CEL_ASSIGN_OR_RETURN(auto iterator, top.GetList().NewIterator());
      frame->iterator_stack().Push(std::move(iterator));
    } break;
    case ValueKind::kMap: {
      CEL_ASSIGN_OR_RETURN(auto iterator, top.GetMap().NewIterator());
      frame->iterator_stack().Push(std::move(iterator));
    } break;
    default:
      // Replace <iter_range> with an error and jump past
      // ComprehensionFinishStep.
      frame->value_stack().PopAndPush(
          cel::ErrorValue(CreateNoMatchingOverloadError("<iter_range>")));
      return frame->JumpTo(error_jump_offset_);
  }

  return absl::OkStatus();
}

absl::Status ComprehensionNextStep::Evaluate1(ExecutionFrame* frame) const {
  if (!frame->value_stack().HasEnough(2)) {