/// <summary>
/// Runs the provided Brainfuck code.
/// </summary>
/// <param name="code">
/// The code to run.
/// </param>
/// <param name="stdin">
/// Optional. The input stream. Console is used if not specified.
/// </param>
/// <param name="stdout">
/// Optional. The ouput stream. Console is used if not specified.
/// </param>
public static void Run(string code, Stream stdin = null, Stream stdout = null)
{
Tape tape = new Tape();
char[] program = code.ToCharArray();
int brackets = 0;
int codePointer = 0;
if (stdin == null)
stdin = Console.OpenStandardInput();
if (stdout == null)
stdout = Console.OpenStandardOutput();
while (codePointer >= 0 && codePointer < program.Length)
{
switch (program[codePointer])
{
case '+':
tape.Cell++;
codePointer++;
break;
case '-':
tape.Cell--;
codePointer++;
break;
case '>':
tape.MoveRight();
codePointer++;
break;
case '<':
tape.MoveLeft();
codePointer++;
break;
case '[':
if (tape.Cell == 0)
{
brackets++;
while (brackets != 0 && ++codePointer < program.Length)
{
if (program[codePointer] == '[')
brackets++;
else if (program[codePointer] == ']')
brackets--;
}
codePointer++;
break;
}
codePointer++;
break;
case ']':
brackets++;
while (brackets != 0 && --codePointer >= 0)
{
if (program[codePointer] == ']')
brackets++;
else if (program[codePointer] == '[')
brackets--;
}
break;
case '.':
stdout.WriteByte((byte)tape.Cell);
codePointer++;
break;
case ',':
tape.Cell = stdin.ReadByte();
codePointer++;
break;
default:
codePointer++;
break;
}
}
}
