Parser.cs

public class Parser
{
    // Will cover in next blog post likely
    private readonly ObjectDependencyManager _objectDependencyManager;

    // All available states
    private readonly ObjectHeaderState _objectHeaderState;
    private readonly ObjectPropertiesState _objectPropertiesState;
    private readonly PropertiesState _propertiesState;
    private readonly GlobalVariablesState _globalVariablesState;
    private readonly ProceduresState _proceduresState;
    private readonly CommentBlockState _commentBlockState;

    // tracks current state
    private ParserState _currentState;

    // Will cover in next blog post
    private NavObjectNode _currentObject;

    public Parser(ObjectDependencyManager objectDependencyManager)
    {
        _objectDependencyManager = objectDependencyManager;
        _objectHeaderState = new ObjectHeaderState(this);
        _objectPropertiesState = new ObjectPropertiesState(this);
        _propertiesState = new PropertiesState(this);
        _globalVariablesState = new GlobalVariablesState(this);
        _propertiesState = new PropertiesState(this);
        _proceduresState = new ProceduresState(this);
        _commentBlockState = new CommentBlockState(this);

        // start in the object header state
        _currentState = ObjectHeaderState;
    }

    // One property to expose each state type...
    // I will show first, but remaining are elided
    public ObjectHeaderState ObjectHeaderState
    {
        get { return _objectHeaderState; }
    }

    // Will cover in next blog post likely
    public ObjectDependencyManager ObjectDependencyManager
    {
        get { return _objectDependencyManager; }
    }

    // Will cover in next blog post
    public NavObjectNode CurrentObject
    {
        get { return _currentObject; }
        set
        {
            _currentObject = value;
            _objectDependencyManager.AddNavObjectToCompile(value);
        }
    }

    // the main driver...parse a file
    // and the state machine cogs begin to turn
    public void ParseFile(string file)
    {
        SetState(ObjectHeaderState);
        using (var rdr = new StreamReader(file))
        {
            while (!rdr.EndOfStream)
            {
                var readLine = rdr.ReadLine();
                if (readLine != null) _currentState.ReadLine(readLine.Trim());
            }
        }
    }

    // Called from within the states to change to another state
    public void SetState(ParserState newState)
    {
        _currentState = newState;
        _currentState.Reset();
    }
}