From: Calvin Bornhofen <calvin.bornhofen@...>
Date: 2013-01-06T01:00:16+09:00
Subject: Re: Best practice for &&, ||, and, or

Hello,

I want to use a consistent style so I don't have to think about the 
precedences that much. This and the fact that I more frequently use && 
and || brings me to the conclusion that 1. is just more useful, because 
I have to write less parentheses which in turn make the code easier to 
read (at least imo). This also makes it easier to learn Ruby/programming 
for newbies.

Compare:

   foo = hsh[:bar] || hsh[:alternative] || "" # I think lines like these 
are quite common, because many libraries like to use hashes as 
parameters and initialization like this is very expressive

to

   foo = ( hsh[:bar] or hsh[:alternative] or "" ) # I think the 
additional parentheses just distract from what I want to accomplish, 
which is just an initialization. Parentheses to me always smell like 
complex computation (which this is not)

In my opinion using || in this case is more clear, because you can read 
the || as "or".

And one thing I want to add to your third proposed practice: In the case 
of "loot = give_money or die" I'd almost certainly think that the or is 
evaluated before the assignment (just because of the different 
precedences) at first.

Just my two cents.

Regards,
Calvin

On 05.01.2013 13:35, sto.mar@web.de wrote:
>   a. in the context of your own projects, and
>   b. with regard to teaching programming newbies
>
> The GitHub Ruby Styleguide [1] states: "The and and or keywords are 
> banned. It's just not worth it. Always use && and || instead".
>
> So what's your practice/recommendation:
>
>   1. use only &&, ||
>   2. use only `and', `or'
>   3. distinguish between boolean expressions (if this && that)
>      and control flow (loot = give_money  or die)
>   4. ???