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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: Memorizing C operator precedence
Date: Mon, 25 Apr 2022 14:48:48 -0700
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Paul N <gw7rib@aol.com> writes:

> On Saturday, April 16, 2022 at 3:28:00 PM UTC+1, Alan Mackenzie wrote:
>
>> Stefan Ram <r...@zedat.fu-berlin.de> wrote:
>>
>>> Alan Mackenzie <a...@muc.de> writes:
>>>
>>>> Breaking up a complicated expression _fragments_ it
>>>
>>> Example for the refactor "extract variable" in pseudocode:
>>>
>>> return quantity * item_price -
>>> max(0, quantity - 500) * item_price * 0.05 +
>>> min(quantity * item_price * 0.1, 100);
>>>
>>> ------------------>
>>>
>>> const base_price = quantity * item_price;
>>> const quantity_discount =
>>> max( 0, quantity - 500 )* item_price * 0.05;
>>> const shipping = min( base_price * 0.1, 100 );
>>> return base_price - quantity_discount + shipping;
>
> How about a compromise?
>
> return quantity * item_price
> - max(0, quantity - 500) * item_price * 0.05  // quantity discount
> + min(quantity * item_price * 0.1, 100);  // shipping

Speaking for myself I would rather see something like this:

   [...]
        unsigned n = quantity;
        double price = item_price;
        return  sale_charge( n, price ) + shipping_charge( n, price );


    double
    sale_charge( unsigned n, double price ){
        return  base_charge( n, price ) - quantity_discount( n, price );
    }

    double
    shipping_charge( unsigned n, double price ){
        return  min( base_charge( n, price ) * 0.1, 100.0 );
    }

    double
    base_charge( unsigned n, double price ){
        return  n * price;
    }

    double
    quantity_discount( unsigned n, double price ){
        return  n > 500 ? (n-500) * price * 0.05  :  0;
    }