From: Robert Dober <robert.dober@...>
Date: 2008-06-11T19:37:52+09:00
Subject: Re: each with else

On Wed, Jun 11, 2008 at 11:09 AM, Thorsten Müller <thorsten@80beans.com> wrote:
> Hi all,
>
> that's just an idea I came up with and thought worth a discussion.
>
> Would it be possible to give each an else part?
>
> For Rails programmers it is very common to do something like this:
>
> In controller search for records:
>
> @orders = Order. find(:all)
>
> In view:
>
> <% unless @orders.empty? then %>
>  <%   @orders.each do |order| %>
>    <%= output order somehow %>
>  <% end %>
> <% else %>
>  output message, that there are no orders
> <% end %>
>
> If each would have it's own else which runs if the
> used array, enumerable or whatever is empty,
> that code could look much nicer:
>
> <% @orders.each do |order| %>
>    <%= output order somehow %>
> <% else %>
>  output message, that there are no orders
> <% end %>
>
> I guess, that would be true for any other Ruby code, too.
>
> Please give your opinions to that idea and if you think
> there would be a chance to get this implemented one day...
>
>
Hmmm maybe you should use map than

As you claimed that this is a Ruby issue I will not write Rails code here

@orders.map{ |order| whatever }.empty? and puts "there are no orders"

I know map with side effects is maybe a little bit counterproductive
for readability and maintenance but in order to use each you have to
enhance Enumerable first.

module Enumerable
    def empty?; first > last end
end

@orders.each{ |order| ... }.empty? and ...

but honestly would it not be better to write

if @orders.empty? then
else
end
?

BTW the implementation of Enumerable#empty? looks much more like a RCR to me.

Cheers
Robert




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---
As simple as possible, but not simpler.
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