From: "David A. Black" <dblack@...>
Date: 2004-08-19T21:18:55+09:00
Subject: Re: When to use parentheses around method args?

Hi --

On Wed, 18 Aug 2004, Richard Dale wrote:

> My problem was the the method:
> 
>   def << aNode
>     @children << aNode
>   end
> 
> I wondered what is this strange new ruby syntax? But as soon as I saw it
> meant this I could follow the code:
> 
>   def <<(aNode)
>     @children << aNode
>   end
> 
> It's like one of the 'Escher mind teasers' where you seen a cube from one
> perspective, and then suddenly your brain flip-flops to another one.
> 
> Are there any rules of thumb for when it's a good idea to leave out the
> brackets and when to use them?

Personally I like to adhere as much as possible to the style
established by Matz and the other core developers, though I know this
attitude has lost popularity in recent years.  Anyway, if you want to
be a conformist sheep like me, you can use the Ruby distribution as
a source of information about coding style:

# These are almost certainly not 100% correct counts, but they give
# you a very good indication of standard practice.  This is
# Ruby 1.8.1.

# All def's:

$ grep "^[[:space:]]*def" `find . -name "*.rb"` | wc -l
   7484

# All the def's with no parentheses:

$ grep "^[[:space:]]*def " `find . -name "*.rb"` | cut -d# -f1 |\
  grep -v "(" | wc -l
   2438

# All of the above which have more than one word other than "def"
# (filtering out one-line defs):

$ grep "^[[:space:]]*def" `find . -name "*.rb"` | cut -d# -f1 | \
  grep -v "(" | grep -v "end$"| ruby -ne "print if split.size > 3" | wc -l
    160

So about 94% of all def's with arguments in the Ruby distribution use
parentheses.

You'll find similar stats for camelCase method/variable names,
indentation by more than two spaces, and other points of style where
Ruby will accept non-conventional practice but conventions and
traditions do exist.  How you deal with these things is up to you.


David

-- 
David A. Black
dblack@wobblini.net