From: Pit Capitain <pit@...>
Date: 2006-03-28T21:31:25+09:00
Subject: Re: Noob: The ruby way to multiple Array by multiple?

Ryan Davis schrieb:
> a = [1, 2, 3]
> b = [4, 5]
> 
> (a * b.size).zip(b * a.size).sort
> # => [[1, 4], [1, 5], [2, 4], [2, 5], [3, 4], [3, 5]]
> 
> ...
> 
> class Array
>   def x(b)
>     a = self
>     (a * b.size).zip(b * a.size)
>   end
> end
> 
> a.x b
> => [[1, 4], [2, 5], [3, 6], [1, 4], [2, 5], [3, 6], [1, 4], [2, 5],  [3, 
> 6]]

Ryan, this works only if a.size and b.size are relatively prime, as in 
your first example. The second example shows the error. If you use sort 
in a different place it should work, though:

   (a * b.size).sort.zip(b * a.size)

Regards,
Pit