Brain Fuck Intepreter

brainfuck.py

def match(code, start, reverse=False):
    count = 0
    begin, end = "[", "]"
    if reverse:
        begin, end = end, begin
    search = code[:start][::-1] if reverse else code[start:]
    for i, c in enumerate(search):
        if c == begin:
            count += 1
        elif c == end:
            if count == 0:
                return start - i - 1 if reverse else start + i
            count -= 1


def brain_luck(code, input):
    memory = {}
    p = 0  # memory pointer
    i = 0  # code pointer
    j = 0  # input pointer
    output = ""
    while i < len(code):
        c = code[i]
        if c == ">":
            p += 1
        elif c == "<":
            p -= 1
        elif c == "+":
            memory[p] = (memory.get(p, 0) + 1) % 256
        elif c == "-":
            memory[p] = (memory.get(p, 0) - 1 + 256) % 256
        elif c == ".":
            output += chr(memory.get(p, 0))
        elif c == ",":
            memory[p] = ord(input[j])
            j += 1
        elif c == "[":
            if memory.get(p, 0) == 0:
                i = match(code, i)
                continue
        elif c == "]":
            if memory.get(p, 0) != 0:
                i = match(code, i, reverse=True) + 1
                continue
        i += 1
    return output

s = ',>+>>>>++++++++++++++++++++++++++++++++++++++++++++>++++++++++++++++++++++++++++++++<<<<<<[>[>>>>>>+>+<<<<<<<-]>>>>>>>[<<<<<<<+>>>>>>>-]<[>++++++++++[-<-[>>+>+<<<-]>>>[<<<+>>>-]+<[>[-]<[-]]>[<<[>>>+<<<-]>>[-]]<<]>>>[>>+>+<<<-]>>>[<<<+>>>-]+<[>[-]<[-]]>[<<+>>[-]]<<<<<<<]>>>>>[++++++++++++++++++++++++++++++++++++++++++++++++.[-]]++++++++++<[->-<]>++++++++++++++++++++++++++++++++++++++++++++++++.[-]<<<<<<<<<<<<[>>>+>+<<<<-]>>>>[<<<<+>>>>-]<-[>>.>.<<<[-]]<<[>>+>+<<<-]>>>[<<<+>>>-]<<[<+>-]>[<+>-]<<<-]'
input = chr(10)

print brain_luck(s, input)