From: Michael Fellinger <m.fellinger@...>
Date: 2010-03-06T05:14:59+09:00
Subject: Re: Conditional keys in hash - out of the box?

On Sat, Mar 6, 2010 at 4:25 AM, Sven S. <svoop@delirium.ch> wrote:
> Hi
>
> Cumbersome title, here's what I'd like to do both elegantly and without
> monkey patching Hash:
>
> Say, I need to pass a hash to a method:
>
> mymethod :this => 'green'
>
> Now I'd like to include a second hash member only if a condition is met:
>
> mymethod :this => 'green, :that => ('blue' if condition)
>
> This of course leaves ":that => nil" in the hash if the condition is not
> met - which is no good, the key should just not be present at all. I
> could delete_if after that, but isn't there a more elegant way?

p({this: 'green'}.merge(1 == 2 ? {that: 'blue'} : {}))
{:this=>"green"}

p({this: 'green'}.merge(1 == 1 ? {that: 'blue'} : {}))
{:this=>"green", :that=>"blue"}


> Thanks for your ideas!
> --
> Posted via http://www.ruby-forum.com/.
>
>



-- 
Michael Fellinger
CTO, The Rubyists, LLC