From: Robert Klemme <shortcutter@...>
Date: 2007-11-28T04:35:02+09:00
Subject: Re: Most elegant way to do this?

On 27.11.2007 20:24, Brian Adkins wrote:
> 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)

Yes, of course.  Copy & paste...

Cheers

	robert