public void ProcessorExecutePerformsNoOpOnHaltState()
{
ITape mockTape = Substitute.For<ITape>();
mockTape.Read().Returns(' ');
IInstructionTable mockTable = Substitute.For<IInstructionTable>();
Processor processor = new Processor(mockTape, mockTable);
Instruction testInstruction = new Instruction();
testInstruction.State = "START";
testInstruction.NextStates[' '] = "HALT";
testInstruction.WriteSymbols[' '] = ' ';
testInstruction.MoveDirections[' '] = MoveDirection.None;
mockTable.GetInstruction(Arg.Any<String>()).Returns(testInstruction);
processor.Execute();
mockTape.ClearReceivedCalls();
mockTable.ClearReceivedCalls();
processor.Execute();
mockTable.Received(0).GetInstruction(Arg.Any<String>());
mockTape.Received(0).Read();
mockTape.Received(0).Write(Arg.Any<char>());
mockTape.Received(0).MoveLeft();
mockTape.Received(0).MoveRight();
}
public void ProcessorDoesNotMoveTapeOnNoMoveInstruction()
{
ITape mockTape = Substitute.For<ITape>();
IInstructionTable mockTable = Substitute.For<IInstructionTable>();
Processor processor = new Processor(mockTape, mockTable);
char symbol = 'a';
Instruction noMoveInstruction = new Instruction();
noMoveInstruction.State = "START";
noMoveInstruction.WriteSymbols[symbol] = symbol;
noMoveInstruction.MoveDirections[symbol] = MoveDirection.None;
noMoveInstruction.NextStates[symbol] = "HALT";
mockTape.Read().Returns(symbol);
mockTable.GetInstruction(Arg.Any<String>()).Returns(noMoveInstruction);
processor.Execute();
mockTable.Received(1).GetInstruction("START");
mockTape.Received(1).Read();
mockTape.Received(1).Write(symbol);
mockTape.Received(0).MoveRight();
mockTape.Received(0).MoveLeft();
}
private static void DrawHead(Processor processor)
{
Console.WriteLine(" _^_");
int stateLength = processor.NextState.Length / 2;
for (int index = 0; index < 39 - stateLength; index++)
{
Console.Write(" ");
}
Console.WriteLine(processor.NextState + " ");
}
public void ProcessorExecuteReturnsFalseOnHaltState()
{
ITape mockTape = Substitute.For<ITape>();
mockTape.Read().Returns(' ');
IInstructionTable mockTable = Substitute.For<IInstructionTable>();
Processor processor = new Processor(mockTape, mockTable);
Instruction testInstruction = new Instruction();
testInstruction.State = "START";
testInstruction.NextStates[' '] = "HALT";
testInstruction.WriteSymbols[' '] = ' ';
testInstruction.MoveDirections[' '] = MoveDirection.None;
mockTable.GetInstruction(Arg.Any<String>()).Returns(testInstruction);
Assert.IsTrue(processor.Execute());
Assert.IsFalse(processor.Execute());
}
public void ProcessorExecutesStartStateFollowedByNextState()
{
ITape mockTape = Substitute.For<ITape>();
mockTape.Read().Returns(' ');
IInstructionTable mockTable = Substitute.For<IInstructionTable>();
Processor processor = new Processor(mockTape, mockTable);
Instruction testInstruction = new Instruction();
testInstruction.State = "START";
testInstruction.NextStates[' '] = "A";
testInstruction.WriteSymbols[' '] = ' ';
testInstruction.MoveDirections[' '] = MoveDirection.None;
mockTable.GetInstruction(Arg.Any<String>()).Returns(testInstruction);
processor.Execute();
mockTable.Received(1).GetInstruction("START");
mockTape.Received(1).Read();
mockTape.Received(1).Write(' ');
mockTape.Received(0).MoveRight();
mockTape.Received(0).MoveLeft();
processor.Execute();
mockTable.Received(1).GetInstruction(testInstruction.NextStates[' ']);
}
public void ProcessorThrowsExceptionOnNullTape()
{
IInstructionTable mockTable = Substitute.For<IInstructionTable>();
Processor processor = new Processor(null, mockTable);
}
public void ProcessorThrowsExceptionOnNullInstructionTable()
{
ITape mockTape = Substitute.For<ITape>();
Processor processor = new Processor(mockTape, null);
}
static void Main(string[] args)
{
Console.OutputEncoding = Encoding.Default;
ITape tape = null;
try
{
tape = new Tape(File.ReadAllText("./init.tap"));
}
catch(Exception)
{
tape = new Tape();
}
IInstructionTable instructionTable = null;
try
{
instructionTable = ParseInstructions(args);
}
catch(Exception ex)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("Failed to load instruction table. " + ex.Message);
Console.ReadLine();
return;
}
Processor processor = new Processor(tape, instructionTable);
Console.CursorVisible = false;
int clockDelay = 500;
try
{
clockDelay = Int32.Parse(ConfigurationManager.AppSettings.Get("ClockDelay"));
}
catch(Exception)
{
}
while(true)
{
Console.SetCursorPosition(0, 0);
DrawTape(tape);
DrawHead(processor);
Console.WriteLine();
Console.WriteLine("Tick: " + processor.Tick);
if(!processor.Execute())
{
break;
}
Thread.Sleep(clockDelay);
}
Console.WriteLine("Execution completed!");
Console.ReadLine();
}