Brainfuck Interpreter in Python

brainfuck.py

from __future__ import annotations

import curses


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

INCREMENT_PTR = ">"
DECREMENT_PTR = "<"
INCREMENT_VAL = "+"
DECREMENT_VAL = "-"
OUTPUT_VAL = "."
INPUT_VAL = ","
LOOP_START = "["
LOOP_END = "]"


def main(stdscr: curses._CursesWindow) -> None:
    """Main function."""
    stdscr.clear()

    data: list[int] = [0] * 30000
    jump_stack: list[int] = []
    data_pointer = 0
    instruction_pointer = 0
    op_code = CODE[instruction_pointer]

    while op_code:
        next_instruction = instruction_pointer + 1

        if data_pointer >= len(data) or data_pointer < 0:
            raise IndexError("Pointer out of bounds")

        if op_code == INCREMENT_PTR:
            data_pointer += 1
        elif op_code == DECREMENT_PTR:
            data_pointer -= 1
        elif op_code == INCREMENT_VAL:
            data[data_pointer] += 1
        elif op_code == DECREMENT_VAL:
            data[data_pointer] -= 1
        elif op_code == OUTPUT_VAL:
            stdscr.addstr(chr(data[data_pointer]))
        elif op_code == INPUT_VAL:
            data[data_pointer] = ord(stdscr.getkey())
        elif op_code == LOOP_START:
            if data[data_pointer] == 0:
                counter = 0
                while instruction_pointer < len(CODE):
                    instruction_pointer += 1
                    counter += CODE[instruction_pointer] == LOOP_START
                    if CODE[instruction_pointer] == LOOP_END:
                        if counter:
                            counter -= 1
                        else:
                            break
            else:
                jump_stack.append(instruction_pointer)
        elif op_code == LOOP_END:
            jump_to = jump_stack.pop()
            if data[data_pointer]:
                next_instruction = jump_to

        try:
            instruction_pointer = next_instruction
            op_code = CODE[instruction_pointer]
        except IndexError:
            break

    stdscr.addstr("\n\nProgram finished. Press any key to exit.")
    stdscr.getkey()


if __name__ == "__main__":
    curses.wrapper(main)