Payload for {:done, %__MODULE__{}} - the terminal effect exit_interpreter (Appendix D) produces once, after top-level final entry, when Statifier.MachineState.status becomes :done. donedata is the top-level final's resolved <donedata> content, or :undefined (the SCXML datamodel's "undefined" value) when the final carries none. donedata_error is that resolution's failure channel (ADR-0021's 2026-09-02 note): nil when the donedata resolved cleanly and nil for a bare final that declared none, and otherwise the data of the error.execution the resolution raised. Without it, donedata: :undefined is the same value for a failed <content expr> and for a final carrying no <donedata> at all, because exit_interpreter/1 discards the internal queue the raise landed in before returning. A <donedata> whose <param>s fail can raise more than one; this field carries the first in document order, and the rest are still lost with the queue. configuration is the full configuration (ADR-0005, ancestors included) as it stood at exit: the full set, so a consumer can observe the terminal position without switching tracing on, since MachineState.configuration is empty by then and Statifier.active_leaf_states/1 correctly reports nothing active. See Statifier.Interpreter.exit_interpreter/1.

There is no c_index: this effect is produced by exit_interpreter itself, not by one executable-content node. macrostep/microstep/ round are the counters as they stand at the moment of termination. See Statifier.Effect.Trace.Done for the trace-effect counterpart, built from the same configuration_at_exit binding.