# NOTE: Even though there are two final states - Error and Done,
#       plantuml shows it as one done state.
statechart:
  name: MappedRangeResultStateMachine Statechart
  preamble: |
    **Context:** Root State
    -----------------------
    Immutable:
      transaction
      snapshot
      mode
      reverse
      mapper

    Mutable:
      iteration
      limit
      begin_sel
      end_sel
    ---------------------------
    **Context:** Fetching State
    ---------------------------
    Immutable:
      fdb_future_key_value_array
    -----------------------------------------------
    **Context:** MappedKeyValueArrayAvailable State
    -----------------------------------------------
    Immutable:
      count
      mkvs
      more

    Mutable:
      index
    --------------------------------
    **Context:** Error State (final)
    --------------------------------
    Immutable:
      fdb_error
  root state:
    name: MappedRangeResultStateMachine
    initial: Fetching
    states:
      - name: Fetching
        transitions:
          - event: FetchOk{mkvs, index, count, more}
            target: MappedKeyValueArrayAvailable
            action: |
              update limit, iteration, begin_sel, end_sel
          - event: FetchDone
            target: Done
          - event: FetchError{fdb_error}
            target: Error
      - name: MappedKeyValueArrayAvailable
        transitions:
          - event: FetchNextBatch{fdb_future_mapped_key_value_array}
            target: Fetching
          - event: FetchDone
            target: Done
      - name: Error
        type: final
      - name: Done
        type: final