Byte Code ABC - 1

bytecode_abc_1.py

class Num:
    def __init__(self, value):
        self.value = value

    def evaluate(self, stack):
        push(stack, self.value)
        return stack

class Add:
    def __init__(self, left, right):
        self.left = left
        self.right = right

    def evaluate(self, stack):
        self.left.evaluate(stack)
        self.right.evaluate(stack)
        add(stack)
        return stack

class Mul:
    def __init__(self, left, right):
        self.left = left
        self.right = right

    def evaluate(self, stack):
        self.left.evaluate(stack)
        self.right.evaluate(stack)
        mul(stack)
        return stack

# Byte Code Instructions    
def push(stack, value):
    stack.append(value)

def add(stack):
    r = stack.pop()
    l = stack.pop()
    stack.append(l + r)

def mul(stack):
    r = stack.pop()
    l = stack.pop()
    stack.append(l * r)

# 1 + 2    
print(Add(Num(1), Num(2)).evaluate([]))

# 1 + 2 + 3
print(Add(Add(Num(1), Num(2)), Num(3)).evaluate([]))

# 5 + 2 * 3
print(Add(Num(5), Mul(Num(2), Num(3))).evaluate([]))