NB: Order of operations is already dealt with by the grammar. Here we can simply match on the type.

def _expression(expression):
    # type: (QuilParser.ExpressionContext) -> Any
    """
    NB: Order of operations is already dealt with by the grammar. Here we can simply match on the type.
    """
    if isinstance(expression, QuilParser.ParenthesisExpContext):
        return _expression(expression.expression())
    elif isinstance(expression, QuilParser.PowerExpContext):
        if expression.POWER():
            return _binary_exp(expression, operator.pow)
    elif isinstance(expression, QuilParser.MulDivExpContext):
        if expression.TIMES():
            return _binary_exp(expression, operator.mul)
        elif expression.DIVIDE():
            return _binary_exp(expression, operator.truediv)
    elif isinstance(expression, QuilParser.AddSubExpContext):
        if expression.PLUS():
            return _binary_exp(expression, operator.add)
        elif expression.MINUS():
            return _binary_exp(expression, operator.sub)
    elif isinstance(expression, QuilParser.SignedExpContext):
        if expression.sign().PLUS():
            return _expression(expression.expression())
        elif expression.sign().MINUS():
            return -1 * _expression(expression.expression())
    elif isinstance(expression, QuilParser.FunctionExpContext):
        return _apply_function(expression.function(), _expression(expression.expression()))
    elif isinstance(expression, QuilParser.AddrExpContext):
        return _addr(expression.addr())
    elif isinstance(expression, QuilParser.NumberExpContext):
        return _number(expression.number())
    elif isinstance(expression, QuilParser.VariableExpContext):
        return _variable(expression.variable())

    raise RuntimeError("Unexpected expression type:" + expression.getText())