From: Ben Stephens <foolfodder@...>
Date: 2005-07-20T05:03:55+09:00
Subject: Re: Regarding rand

Thanks guys,

Daniel, I started out with something similar to that, although yours
is alot better, but then thought it would be nice to have something
like random 'a'..'z' aswell or even random Thing.new(1)..Thing.new(6)
. Which i'll probably not need anyway so i'll 'borrow' yours if I may.

Jacob, I'm new to Ruby but seeing code like that fills me with a
feeling of well-being.

Devin, thanks, 1) will do!, i'm going to go and have a look at the
pickaxe to see why. 2) I was vaguely aware that creating the arrays
could be a bad idea for big ranges but couldn't work out how to get
the nth member of a range except by doing something like

value = range.first
for  1..n
  value = value.succ
end

which seemed a bit nasty or by getting the entries which seemed quite
nice in light of the chapter I read about duck typing

Ben (Ruby Newbie)

On 7/19/05, twifkak@comcast.net <twifkak@comcast.net> wrote:
> I like it! Two notes:
> 
> 1. Use #respond_to? instead of ::method_defined? This allows for singleton methods.*
> 
> 2. What other people are saying about the cost of creating an array each time. You might use each_with_index (which is stupidly slow for Arrays), or might implement a different rand method for Range, Array, etc.
> 
> Devin
> 
> > I was reading Learn to Program by Chris Pine yesterday, in one bit it says:
> >       ' Note that I used rand(101) to get back numbers from 0  to 100, and
> > that rand(1) always gives back 0.'
> >
> > I was wondering if rand() could support syntax like:
> >    rand(0..100)
> >
> > Here's my go:
> >
> > def random(value)
> >       if value.class.method_defined? 'entries'
> >               entries = value.entries
> >               entries[rand(entries.length)]
> >       else
> >               rand(value)
> >       end
> > end
> >
> > this works with arrays and hashes too.
> >
> > I'm coming to Ruby via RoR and i'm loving it, I should be writing a
> > web app and i'm playing with Ruby instead.
> >
> > Ben
> >
> 
> 
> 
>