## StateMachine processing algorithm

### StubbleNotify structure

StubbleNotify {
    int type; // - notify type
    int char; // - processed symbol code
    dynamic value; // - некоторое передаваемое значение
}

### Insert data by path

```
  { { b i l l N u m }  }
0 1 2 3 4 5 6 7 8 9 10 11
```

0. RootState (initial state)
1. (`{`) `RootState` -> `OpenBracketState`: since the opening bracket is met, go to the standby state of the second bracket; -> `OpenBracketState`
2. (`{`) `OpenBracketState` -> `RootState.notify()` : since the character is a bracket, we return the flag that the second opening bracket is found with the requirement to notify the previous state; -> `GetSequenceState`
3. ({`b`) `GetSequenceState` -> `RootState.notify()` : the `b` character indicates that structure is a `path`; notify the previous state by passing the corresponding flag in notify and the first character `b`; -> `InsertContextDataState.init()` with character `b` -> `GetPathState  ` 
4-9. Adding symbols to GetPathState.path variable
10. (`}`) `GetPathState` -> `InsertContextDataState.notify()`: since the symbol `}` is not one of the allowed in the path, the parent state is notified with a structure of the following form:

```
    type: notify.PATH_STATE_RESULT,
    char: '}',
    value: 'billNum'
```

This will cause a transition to the CloseBracketState state - waiting for the second closing bracket

11. (`}`) CloseBracketState -> InsertContextDataState.notify: pass the flag that the second bracket is. After that InsertContextDataState using the saved name billNum tries to find in the context a value with that `path`, and if it is (not null) then returns its string representation as a result and goes back to `RootState`. Otherwise, it will return `null` as the result.

```mermaid
sequenceDiagram
  participant RootState
  participant OpenBracketState
  participant GetSequenceState
  participant InsertContextDataState
  participant GetPathState
  participant CloseBracketState
  Note right of RootState: character: {
  RootState->>OpenBracketState:  
  Note right of OpenBracketState: character: {
  OpenBracketState->>RootState: notify: SECOND_OPEN_BRACKET_FOUND
  RootState->>GetSequenceState:  
  Note right of GetSequenceState: character: b
  GetSequenceState->>RootState: CONTEXT_DATA_SEQUENCE
  RootState->>InsertContextDataState: init('b')
  InsertContextDataState->>GetPathState: init('b')
    loop characters 4-9
        GetPathState->>GetPathState: add character to path
    end
  Note right of GetPathState: character: {
  GetPathState->>InsertContextDataState: notify: `type: .PATH_STATE_RESULT, char: '}', value: 'billNum'`
  InsertContextDataState->>InsertContextDataState: save 'billNum' to 'path' variable

  InsertContextDataState->>CloseBracketState:  
  Note right of CloseBracketState: character: }
  CloseBracketState->>InsertContextDataState: notify: CLOSE_BRACKET_FOUND
  InsertContextDataState->>RootState: result: 'value of 'billNum' in context'
```