public BrainfuckSteps(BrainfuckToken first, BrainfuckMemoryTape memoryTape, IBrainfuckStream stream)
{
_first = first ?? throw new ArgumentNullException(nameof(first));
_memoryTape = memoryTape ?? throw new ArgumentNullException(nameof(memoryTape));
_stream = stream;
}
public static BrainfuckSteps Create(IEnumerable <BrainfuckToken> tokens, BrainfuckMemoryTape memoryTape,
IBrainfuckStream stream)
{
return(new BrainfuckSteps(tokens.FirstOrDefault(), memoryTape, stream));
}
public BrainfuckTokenSequence Parse(TextReader streamReader, BrainfuckMemoryTape memoryTape = null)
{
memoryTape = memoryTape ?? new BrainfuckMemoryTape();
var leftBracketStack = new Stack <LeftBracketToken>();
BrainfuckToken first = null;
BrainfuckToken prev = null;
var index = -1;
while (0 <= streamReader.Peek())
{
++index;
var c = (char)streamReader.Read();
BrainfuckToken current = null;
switch (c)
{
case '>':
current = new RightShiftToken();
break;
case '<':
current = new LeftShiftToken();
break;
case '+':
current = new PlusToken();
break;
case '-':
current = new MinusToken();
break;
case '.':
current = new DotToken();
break;
case ',':
current = new SemicolonToken();
break;
case '[':
{
var leftBracket = new LeftBracketToken();
leftBracketStack.Push(leftBracket);
current = leftBracket;
}
break;
case ']':
{
if (leftBracketStack.Count == 0)
{
throw new InvalidOperationException();
}
var leftBracket = leftBracketStack.Pop();
var rightBracket = new RightBracketToken();
leftBracket.RightBracketToken = rightBracket;
rightBracket.LeftBracketToken = leftBracket;
current = rightBracket;
}
break;
default:
break;
}
if (current == null)
{
continue;
}
current.MemoryTape = memoryTape;
current.Index = index;
if (prev != null && prev.Next == null)
{
prev.SetNextIndexToken(current);
}
prev = current;
if (first != null)
{
continue;
}
first = current;
}
if (leftBracketStack.Count != 0)
{
throw new InvalidOperationException();
}
return(new BrainfuckTokenSequence(first));
}
