""" Brainfuck is an esosteric programming langage. There is a memory array (without fixed size) that holds value from 0 to 255. By default, it is initialized to 0. A data pointer is used to access this memory. By default, the data pointer points to the first memory byte. The goal of the langage is manipulating this data pointer in order to get results. Here are the instructions supported : - '>' : increments the data pointer - '<' : decrements the data pointer - '+' : increments value at data pointer - '-' : decrements value at data pointer - '[' : jumps to next ']' if memory at data pointer is 0 - ']' : jumps to previous '[' if memory at data pointer is not 0 - '.' : output memory at data pointer as ASCII char - ',' : reads a byte from stdin and store it at data pointer """ class BrainfuckInterpreter: MEMORY_SIZE = 2000 def __init__(self, code, Input): self.code = code self.input = Input # memory and pointers self.stack = [0 for i in range(self.MEMORY_SIZE)] self.esp = 0 self.eip = 0 # other self.running = True def movPointer(self, direction): """Move the memory pointer left (-1) or right (1)""" self.esp += direction if self.esp == len(self.stack): self.stack.append(0) def incDecMemory(self, n): """Increment or decrement memory at esp following the value of n""" self.stack[self.esp] += n self.stack[self.esp] %= 256 def getMemoryByte(self): """Return the byte at memory address esp""" return self.stack[self.esp] def getInputByte(self, data): """Read a byte from stdin and store it at esp""" self.stack[self.esp] = ord(data) def goBack(self): """Jump to the last [ if memory at esp != 0""" if self.getMemoryByte() == 0: return True count = 0 while count != -1: self.previous() if self.code[self.eip] == "]": count += 1 elif self.code[self.eip] == "[": count -= 1 self.next() def goNext(self): """Jump to next ] if memory at esp is 0""" if self.getMemoryByte() != 0: return True count = 0 while count != -1: self.next() if self.code[self.eip] == "[": count += 1 elif self.code[self.eip] == "]": count -= 1 self.next() def next(self): """Increment the instruction pointer""" self.eip += 1 if self.eip >= len(self.code): self.exit() def previous(self): """Decrement the instruction pointer""" self.eip -= 1 if self.eip < 0: self.exit() def exit(self): """Set running flag to 0 in order to exit""" self.running = False def run(self): """Main loop of the program : run the brainfuck code""" self.output = [] while self.running: increment = True instruction = self.code[self.eip] if instruction == ">": self.movPointer(1) elif instruction == "<": self.movPointer(-1) elif instruction == "+": self.incDecMemory(1) elif instruction == "-": self.incDecMemory(-1) elif instruction == ".": self.output.append(self.getMemoryByte()) elif instruction == ",": self.getInputByte(self.input[0]) self.input = self.input[1:] elif instruction == "[": increment = self.goNext() elif instruction == "]": increment = self.goBack() if increment: self.next() def brain_luck(code, Input): """Take a brainfuck code and a stdin input and execute it""" interpreter = BrainfuckInterpreter(code, Input) interpreter.run() return "".join(map(chr, interpreter.output)) #print(brain_luck(',>,<[>[->+>+<<]>>[-<<+>>]<<<-]>>.', chr(8) + chr(9))) print(brain_luck('++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.', ''))

Brainfuck Interpreter