Rails - Jan 2007 - nested looping

Is there a different way to nest multiple loops?

arr = []
var1.each do |a|
  var2.each do |b|
     var3.each do |c|
        function(a,b,c)
        arr << b if !arr.include?(b)
     end
  end
end

Just wondering if there was a way to clean up these 8 lines in order to
run the 2 lines inside.

its possible to write a single loop
var1.each {|a| single_line_of_code(a)}

but would this work and follow conventions to just dump the rest inside?

-- 
Posted via http://www.ruby-forum.com/.

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

Alex Treber wrote:
> Is there a different way to nest multiple loops?
Not built into the Ruby language as far as I know, but there''s nothing 
stopping you from rolling your own code if you need to do a lot of this:

array1 = [ 1, 2, 3 ]
array2 = [ 4, 5, 6 ]
array3 = [ 7, 8, 9 ]

def iterate_over(*args, &block)
  def _over(memo, rest, block)
    if rest.empty?
      block.call(memo)
    else
      (head, *tail) = rest
      head.each do |x|
        _over(memo + [x], tail, block)
      end
    end
  end
  _over([], args, block)
end

iterate_over(array1, array2, array3) do |x, y, z|
  puts("#{x} #{y} #{z}")
end

-- 
Posted via http://www.ruby-forum.com/.

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---