public static OpcodeInstruction FromLine(string line)
{
OpcodeInstruction op = new OpcodeInstruction();
op.LineOrigin = line;
string[] parts = line.Split(' ');
op.Argument = Int32.Parse(parts[1]);
switch (parts[0])
{
case "nop":
op.Action = op.NoOperation;
op.FlipAction = op.Jump;
op.Undo = op.UndoNoOperation;
op.UndoFlip = op.UndoJump;
break;
case "acc":
op.Action = op.Accumulate;
op.Undo = op.UndoAccumulate;
break;
case "jmp":
op.Action = op.Jump;
op.FlipAction = op.NoOperation;
op.Undo = op.UndoJump;
op.UndoFlip = op.UndoNoOperation;
break;
}
return(op);
}
private void ExecuteOrThrow(OpcodeInstruction opcode)
{
if (opcode.AlreadyExecuted)
{
throw new OpcodeAlreadyExecutedException(Accumulator, InstructionPointer, Opcodes[InstructionPointer]);
}
Execute(opcode);
}
private void ExecuteOrRewindAndBranch(OpcodeInstruction opcode)
{
if (opcode.AlreadyExecuted)
{
Console.WriteLine($"Blocked at IP {InstructionPointer}. Undoing...");
OpcodeInstruction previousOpcode;
do
{
previousOpcode = OpcodeHistory.Pop();
previousOpcode.AlreadyExecuted = false;
previousOpcode.Undo(this);
Console.WriteLine("Undoing {" + InstructionPointer + "} " + previousOpcode);
} while (!previousOpcode.IsJumpOrNop());
while (true)
{
Console.WriteLine("Flipping {" + InstructionPointer + "} " + previousOpcode);
previousOpcode.AlreadyExecuted = true;
previousOpcode.FlipAction(this);
OpcodeHistory.Push(previousOpcode);
try
{
RunUntilTheEnd();
Console.WriteLine("Run successful, accumulator is " + Accumulator);
return;
}
catch (Exception)
{
OpcodeInstruction branchOpCode = OpcodeHistory.Pop();
while (branchOpCode != previousOpcode)
{
branchOpCode.AlreadyExecuted = false;
branchOpCode.Undo(this);
Console.WriteLine("Undoing {" + InstructionPointer + "} " + branchOpCode);
branchOpCode = OpcodeHistory.Pop();
}
branchOpCode.AlreadyExecuted = false;
Console.WriteLine("Undoing flip {" + InstructionPointer + "} " + branchOpCode);
branchOpCode.UndoFlip(this);
do
{
previousOpcode = OpcodeHistory.Pop();
previousOpcode.AlreadyExecuted = false;
previousOpcode.Undo(this);
Console.WriteLine("Undoing {" + InstructionPointer + "} " + previousOpcode);
} while (!previousOpcode.IsJumpOrNop());
}
}
}
else
{
Console.WriteLine("Doing {" + InstructionPointer + "} " + opcode);
Execute(opcode);
}
}
public OpcodeAlreadyExecutedException(int accumulator, int instructionPointer, OpcodeInstruction opcode)
{
Accumulator = accumulator;
InstructionPointer = instructionPointer;
Opcode = opcode;
}
private void Execute(OpcodeInstruction opcode)
{
OpcodeHistory.Push(opcode);
opcode.AlreadyExecuted = true;
opcode.Action(this);
}