From: Phrogz <phrogz@...>
Date: 2009-02-16T08:03:23+09:00
Subject: Re: Iterating a changing Hash under 1.9.1

On Feb 15, 2:55 pm, Charles Oliver Nutter <charles.nut...@sun.com>
wrote:
> Phrogz wrote:
> > The following code shows that Hash#each under 1.9.1p0 does not iterate
> > over keys added during iteration:
> >   a = [ 1, 2, 3 ]; h = { 0=>0 }
> >   h.each{ |k,v| h[a[k]] = a[k] }
> >   p h
> >   #=> {0=>0, 1=>1}
>
> In this case, you're only reassigning the same keys over and over again.
> Since they're just being reassigned, they don't get pushed to the end of
> the iteration and you don't loop forever.

I think you're wrong.
Initial state: { 0=>0 }
First loop: k is 0, a[0] is 1, assign h[1]=>1
A brand new key/value has been inserted to the hash this point.
If #each then covered the next key/value pair:
Second loop: k is 1, a[1] is 2, assign h[2]=>2 (and so on)