public Stack Apply(Stack s)
{
if (innerInstruction == null)
{
throw new Exception("NYI");
}
else
{
return(innerInstruction.Apply(s));
}
}
private static int FindLargestValue(IEnumerable <string> rawInstructions)
{
var registers = new Dictionary <string, int>();
foreach (string rawInstruction in rawInstructions)
{
Instruction instr = CreateInstruction(rawInstruction);
instr.Apply(registers);
}
return(registers.Values.Max());
}
private static int FindLargestValueAtAnyTime(IEnumerable <string> rawInstructions)
{
var registers = new Dictionary <string, int>();
int maxValue = int.MinValue;
foreach (string rawInstruction in rawInstructions)
{
Instruction instr = CreateInstruction(rawInstruction);
int newValue = instr.Apply(registers);
maxValue = Math.Max(newValue, maxValue);
}
return(maxValue);
}
/// <summary>
/// "Steps" on instruction forwards - Executes a single instruction.
/// </summary>
/// <param name="instruction">The instruction to execute.</param>
public void Step(Instruction instruction)
{
Machine = instruction.Apply(Machine);
}
public virtual Stack Apply(Stack stack)
{
var acceptedArguments = new Stack();
var binding = new Dictionary <string, Type>();
Instruction foundInstruction = null;
int[] acceptedArgumentsCount = new int[instructions.Count()];
int i = 0;
foreach (var instruction in instructions)
{
acceptedArguments.Clear();
binding.Clear();
IEnumerator stackContents = stack.GetEnumerator();
foreach (Type consume in instruction.inputTypes)
{
if (!stackContents.MoveNext())
{
// Not enough elements.
// break;
if (tryBestFit)
{
return(stack);
}
else
{
throw new Exception("Not enough arguments.");
}
// goto notFound;
// return NotEnoughElements(stack, acceptedArguments);
}
object o = stackContents.Current;
var t = o.GetType();
Type consumeType = consume;
// if (t == consume) {
if (Variable.IsVariableType(consume))
{
// XXX What is going on here?
// We accept it. But we should track that it now means this type
// and fail it it changes.
var v = Variable.Instantiate(consume);
if (binding.TryGetValue(v.name, out Type vType))
{
consumeType = vType;
}
else
{
binding.Add(v.name, t);
consumeType = t;
}
}
if (consumeType.IsAssignableFrom(t))
{
acceptedArgumentsCount[i]++;
acceptedArguments.Push(o);
}
else
{
goto notFound;
// break;
}
}
foundInstruction = instruction;
// break;
notFound:
;
i++;
}
// Then run the real instruction.
if (foundInstruction != null)
{
return(foundInstruction.Apply(stack));
}
else
{
if (!tryBestFit)
{
throw new Exception($"Unable to find an instruction that matches the types.");
}
else
{
var max = acceptedArgumentsCount.Max();
// We're going to do a little reordering of the first argument that
// doesn't match the max number of arguments.
var temp = new Stack();
// Capture the good arguments.
for (int j = 0; j < max; j++)
{
temp.Push(stack.Pop());
}
// Create a continuation for the bad argument.
var code = new Stack();
code.Push(stack.Pop());
code.Push(this);
// Push the good arguments back onto the stack.
while (temp.Any())
{
stack.Push(temp.Pop());
}
stack.Push(new Continuation(code));
return(stack);
}
}
}
