From: Rob Sanheim <rsanheim@...>
Date: 2007-01-15T08:26:47+09:00
Subject: Re: return_on

On 1/13/07, Trans <transfire@gmail.com> wrote:
>
> Simon Strandgaard wrote:
> > On 1/10/07, Trans <transfire@gmail.com> wrote:
> > > Sometimes i do this:
> > >
> > >   return x if x
> > >
> > > Anyway to code it as:
> > >
> > >   return_on x
> > >
> >
> > I cannot recall I ever have used return, in this way,
> > but my coding style may be 5% different than yours.
> > Maybe I can improve my minimal insight.
> >
> > Any good (larger) examples of this thing?
>
> I don't really have any examples that are repleat with it, but as to
> insight it's especially convenient when caching a return value:
>
>   def x
>     return_on @cache[:x]
>     # do stuff
>     @cache[:x] = result_of_stuff
>   end
>
> this gets rid of an extraneous variable too b/c otherwise, the more
> efficient impl. is:
>
>   def x
>     r = @cache[:x]
>     return r if r
>     # do stuff
>     @cache[:x] = result_of_stuff
>   end
>
> funny thing i just came across a similar case for break. how would you
> DRY this up and get rid of 'result'?
>
>     result = nil
>     files.each do
>       result = require file
>       break if result
>     end
>     if result
>       ...
>
> t.

Much like returning in ActiveSupport:
http://weblog.jamisbuck.org/2006/10/27/mining-activesupport-object-returning

- rob