From: Brian Adkins <lojicdotcom@...>
Date: 2007-11-28T04:25:02+09:00
Subject: Re: Most elegant way to do this?

On Nov 27, 11:53 am, Robert Klemme <shortcut...@googlemail.com> wrote:
> 2007/11/27, Brian Adkins <lojicdot...@gmail.com>:
>
>
>
> > On Nov 26, 7:17 pm, rbysam...@gmail.com wrote:
> > > Are there any more elegant, concise, pithy, and more Rubyish ways of
> > > doing this?
>
> > > def roll(number_of_dice)
> > >     sum = 0
> > >     number_of_dice.times do
> > >         sum += rand(5).next
> > >     end
> > >     sum
> > > end
>
> > > Thanks in advance!
>
> > As others have pointed out, you need rand(6).next to get (1..6);
> > otherwise, it's hard to improve on what you have here. This is a
> > simple, iterative mathematical function. I personally don't think
> > using map, inject, etc. is more "Rubyish" in this context, just 2 to 3
> > times slower.
>
> > The interface is "roll n" regardless of the underlying implementation,
> > so you might as well make it fast.
>
> > One style improvement might be to use a one line block:
>
> > def roll num_dice
> >   sum = 0
> >   num_dice.times { sum += rand(6).next }
> >   sum
> > end
>
> > You can make it ~10% faster (with the loss of some readability) by not
> > invoking next each time and just summing at the end:
>
> > def roll num_dice
> >   sum = 0
> >   num_dice.times { sum += rand(6) }
> >   sum + num_dice
> > end
>
> I guess there is even more room for improvement by doing this:
>
> def roll num_dice
>   sum = roll num_dice
>   num_dice.times { sum += rand(6) }
>   sum
> end
>
> SCNR ;-)

No apology necessary, I beat you to it :) (I assume you meant sum =
num_dice)