AI BF.py

"""
Make a brainfuck interpreter.
"""

import sys

bf = "++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>."

def run(program):
    inputptr = 0
    data = [0]
    ptr = 0
    head = 0

    while head < len(program):
        if program[head] == ">":
            ptr += 1
            if ptr == len(data):
                data.append(0)
        elif program[head] == "<":
            ptr -= 1
        elif program[head] == "+":
            data[ptr] = (data[ptr] + 1) % 256
        elif program[head] == "-":
            data[ptr] = (data[ptr] - 1) % 256
        elif program[head] == ".":
            sys.stdout.write(chr(data[ptr]))
        elif program[head] == ",":
            data[ptr] = ord(sys.stdin.read(1))
        elif program[head] == "[":
            if data[ptr] == 0:
                count = 1
                while count != 0:
                    head += 1
                    if program[head] == "[":
                        count += 1
                    elif program[head] == "]":
                        count -= 1
        elif program[head] == "]":
            if data[ptr] != 0:
                count = 1
                while count != 0:
                    head -= 1
                    if program[head] == "]":
                        count += 1
                    elif program[head] == "[":
                        count -= 1
        head += 1

if __name__ == "__main__":
    if len(sys.argv) == 2:
        run(sys.argv[1])
    else:
        run(bf)