From: Mathieu Bouchard <matju@...>
Date: 2000-12-10T13:33:36+09:00
Subject: [ruby-talk:6996] Re: parallel array traversal

> Is there a way to do a parallel traversal of a group of arrays in Ruby?
> Or more generally move a collection of index variables in lock-step?
> Currently, in Ruby:
>    for (x,y,z) in [a1, a2,a3]
> has a different and vary valid semantics.     

code below:

class Array
	def each2(&p)
		collect {|a|
			a.length
		}.min.times {|i|
			yield collect {|a|a[i]}
		}
	end
end



note that turning the above into Common Lisp's "map" function should
be fairly easy. (about 8 more chars.)

matju