public static TuringMachine FromText(string[] lines)
{
TuringMachineData data = null;
string initialState = null;
string[] goalStates = new string[0];
List <TuringMachineInstruction> instructions = new List <TuringMachineInstruction>();
foreach (var line in lines)
{
//Check if is comment
var cleanedLine = line.Trim();
if (cleanedLine.StartsWith("@"))
{
continue;
}
if (cleanedLine.StartsWith("fita "))
{
if (data != null)
{
throw new ArgumentException($"Cannot redefine data", nameof(lines));
}
data = new TuringMachineData(cleanedLine.Substring(5)); //Ignore 'fita '
}
else if (cleanedLine.StartsWith("init "))
{
if (initialState != null)
{
throw new ArgumentException($"Cannot redefine initial state", nameof(lines));
}
initialState = cleanedLine.Substring(5);
}
else if (cleanedLine.StartsWith("accept "))
{
if (goalStates.Any())
{
throw new ArgumentException($"Cannot redefine goal states", nameof(lines));
}
goalStates = cleanedLine.Substring(7).Trim().Split(",");
}
else if (!string.IsNullOrWhiteSpace(cleanedLine))
{
try
{
var instruction = TuringMachineInstruction.FromString(cleanedLine);
instructions.Add(instruction);
}
catch (ArgumentException e)
{
throw new ArgumentException($"Could not parse line {cleanedLine}: {e.Message}", e);
}
}
}
return(new TuringMachine(data, initialState, goalStates, instructions.ToArray()));
}
private TuringMachine(TuringMachineData data,
string initialState,
string[] goalStates,
TuringMachineInstruction[] instructions)
{
Data = data;
CurrentState = initialState;
GoalStates = goalStates;
Instructions = instructions;
MachineState = State.Ready;
Result = null;
}
