From: "Stephan J. Schmidt" <stephan.schmidt@...>
Date: 2002-05-29T22:12:45+09:00
Subject: Re: Idioms

Thanks for your reply, I will use this.
Thanks to the other people,  too, I will look into
the supplied URLS,
bye
-stephan

On Wed, 2002-05-29 at 14:35, nobu.nokada@softhome.net wrote:
> Hi,
> 
> At Wed, 29 May 2002 20:58:59 +0900,
> Stephan J. Schmidt <stephan.schmidt@neotis.de> wrote:
> > Could someone point me to idioms about ruby, e.g. 
> > something shorter to
> > 
> > if not hash.key?(key)
> >   hash[key] << value
> > end 
> 
> If you want to add `value' only when the `hash' doesn't have
> the `key':
> 
>   hash.fetch(key) {hash[key] = [value]}
> 
>   hash[key] ||= [value]
> 
> If you want to add `value' to the `hash' with making a list
> automatically:
> 
>   (hash[key] ||= []) << value
> 
>   hash.fetch(key) {hash[key] = []} << value
> 
>   hash = Hash.new([])
>   hash[key] += [value]
> 
>   # 1.7 feature
>   hash = Hash.new {|h, i| h[i] = []}
>   hash[key] << value
> 

> -- 
> Nobu Nakada