From: Justin Collins <justincollins@...>
Date: 2013-01-07T11:34:10+09:00
Subject: Re: Best practice for &&, ||, and, or

On 01/05/2013 04:35 AM, sto.mar@web.de wrote:
> Hi group,
>
> I really would be interested in your thoughts about this
>
>    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. ???
>
> 1. and 2. might require extra parentheses that often could be
> avoided with 3., but using parentheses might be clearer anyway.
> Especially for students who might have a hard time coping with
> the different precedences.
>
> I tend to 1., and for own projects maybe to 3.
>
> Regards,
> Marcus
>
>
> [1] https://github.com/styleguide/ruby/
>

I think I'm in the minority here, so I'll give my minority opinion: For 
my own projects I prefer and/or and only use &&/|| for assignments. 
Looking through one of my codebases, I see 312 uses of "and" and 8 uses 
of "&&" (mostly from other contributors).

Why? Because I also dislike using parentheses for method calls, which 
again seems to be becoming a minority preference. (Also, by default vim 
highlights and/or but not &&/|| and I like pretty colors.)

irb(main):001:0> def x *args; true; end
=> nil
irb(main):002:0> def y *args; true; end
=> nil
irb(main):003:0> if x 1 and y 2
irb(main):004:1>   puts "all good"
irb(main):005:1> end
all good
=> nil
irb(main):006:0> if x 1 && y 2
irb(main):007:1>   puts "not all good"
irb(main):008:1> end
SyntaxError: (irb):6: syntax error, unexpected tINTEGER, expecting 
keyword_do or '{' or '('
(irb):8: syntax error, unexpected keyword_end, expecting $end
	from /home/justin/.rvm/rubies/ruby-1.9.3-p327/bin/irb:12:in `<main>'


I haven't spent much time teaching others, so I don't really have an 
opinion on that. I assume those coming from other languages would be 
more comfortable with &&/||.

I also prefer to use "not" because that stands out more to me than "!".

-Justin