From: Dave Burt <dave@...>
Date: 2005-08-08T07:46:07+09:00
Subject: Re: cartesian product

walter a kehowski wrote...
> cartprod.rb:24: syntax error
>        (c ||= []) << ae,be
>                         ^
> cartprod.rb:26: syntax error
> cartprod.rb:132: syntax error

class Array
  def cartprod(b)
    each do |ae|
      b.each do |be|
        if block_given?
          yield ae, be  # <-- you can yield multiple objects
        else
          (c ||= []) << [ae, be]   # <-- you need to put (ae, be) in a 
single
                                   # object (i.e. an array) to put in an 
array
        end
      end   # <-- you had missed 2 closing braces (line 132 error)
    end
    c  # <-- you want to return this if no block was given
  end
end

Cheers,
Dave