from error import *

CMDs = ["add", "sub", "mul", "div"]


def CheckArg(operand):
    run = False
    if operand[0].isRegister():
        if operand[1].isRegister():
            run = True
    elif operand[0].isRegister():
        if operand[1].isImmediate():
            run = True
    else:
        raise BadOperand()
    return run


def add(self, operand):
    run = CheckArg(operand)
    if run:
        a = operand[0].get()
        b = operand[1].get()
        operand[0].set(a + b)


def sub(self, operand):
    run = CheckArg(operand)
    if run:
        a = operand[0].get()
        b = operand[1].get()
        operand[0].set(a - b)


def mul(self, operand):
    run = CheckArg(operand)
    if run:
        a = operand[0].get()
        b = operand[1].get()
        operand[0].set(a * b)


def div(self, operand):
    run = CheckArg(operand)
    if run:
        a = operand[0].get()
        b = operand[1].get()
        operand[0].set(a // b)