Method DoEvaluate

eval/eval/function_step.cc:244–269

}

absl::StatusOr<Value> AbstractFunctionStep::DoEvaluate(
    ExecutionFrame* frame) const {
  // Create Span object that contains input arguments to the function.
  auto input_args = frame->value_stack().GetSpan(num_arguments_);

  std::vector<cel::Value> unknowns_args;
  // Preprocess args. If an argument is partially unknown, convert it to an
  // unknown attribute set.
  if (frame->enable_unknowns()) {
    auto input_attrs = frame->value_stack().GetAttributeSpan(num_arguments_);
    unknowns_args = CheckForPartialUnknowns(frame, input_args, input_attrs);
    input_args = absl::MakeConstSpan(unknowns_args);
  }

  // Derived class resolves to a single function overload or none.
  CEL_ASSIGN_OR_RETURN(ResolveResult matched_function,
                       ResolveFunction(input_args, frame));

  // Overload found and is allowed to consume the arguments.
  if (matched_function.has_value() &&
      ShouldAcceptOverload(matched_function->descriptor, input_args)) {
    return Invoke(*matched_function, id(), input_args, *frame);
  }

  return NoOverloadResult(name_, input_args, receiver_style_, *frame);
}

absl::Status AbstractFunctionStep::Evaluate(ExecutionFrame* frame) const {
  if (!frame->value_stack().HasEnough(num_arguments_)) {