From: dblack@...
Date: 2003-03-29T06:53:34+09:00
Subject: Re: Need #collect! on partial array

Hi --

On Sat, 29 Mar 2003, Jim Freeze wrote:

> Hi:
>
> Recently I needed to modify an array.
> The array was part of a hash element, so
> it had to be modified in place.
>
> #collect! would have been a great way to go,
> but I did not need to modify the whole array.
>
> For example
>
>   a=%w{one two three}
>
>   a.collect! { |i| i.upcase }
>
> will modify the whole array.
>
>   a[1..-1].collect! { |i| i.upcase }
>
> will modify the anonymous array created by a[1..-1],
> but not a.
>
> This could have been solved with #collect_with_index!
> but AFAIK, this does not exist.

Citizens for MWI [map_with_index] welcomes you to its ranks :-)  But I
think it's been rejected.

> Is there another way to achieve this same affect?

You could do some variant of:

  (0...a.size).each {|i| <do something, or not, with a[i]>}


David

-- 
David Alan Black
home: dblack@superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav