From: Christopher Dicely <cmdicely@...>
Date: 2009-10-14T13:51:26+09:00
Subject: Re: no Enumerator#[] ?

On Tue, Oct 13, 2009 at 2:49 PM, Roger Pack <rogerpack2005@gmail.com> wrote:
> Currently
>
>>> "ab\r\nc".lines[0]
> NoMethodError: undefined method `[]' for #<Enumerator:0x155f220>
>        from (irb):1
>        from C:/installs/ruby191p243p2/bin/irb:12:in `<main>'
>
> Doesn't it seem reasonable for this to exist?

Enumerators may not be rewindable, so [], which would presumably
provide random access to the values returned by the Enumerator may not
be all that reasonable. On the other hand, any Enumerator for which
rewind is usable also could support [], though any general
implementation using rewind and each would be fairly inefficient.