From: Intransition <transfire@...>
Date: 2010-04-17T10:23:31+09:00
Subject: Re: Is it possible, a fully general Enumerable#recursive ?



On Apr 16, 5:44 pm, Robert Dober <robert.do...@gmail.com> wrote:
> On Fri, Apr 16, 2010 at 11:20 PM, Colin Bartlett<colin...@googlemail.com> wrote:
>
> <snip>>   "After working on this for far too long, I have concluded that
> >    a highly generalized implementation of recursion for all
> >    (or at least most) enumerable methods not feasible.")
>
> I beg to differ
> module Enumerable
>   def recursive_each &blk
>     each do | ele |
>       Enumerable === ele ? ele.recursive_each(&blk) : blk[ele]
>     end
>   end
>
>   def rec_enum; enum_for :recursive_each end
> end
>
> x=[ :a, 42, [:b, :c], {:a=> 42, :b => [1,2]}]
>
> rx = x.rec_enum
>
> p rx.to_a
> p rx.any?{ |x| x > 41 rescue false }
> p rx.map{ |x| "<#{x}>" }.join(", ")

Yes and no. See my previous post about preserving structure.