From: Patrick Fernie <patrick.fernie@...>
Date: 2007-02-06T00:29:42+09:00
Subject: Re: Proc vs lambda vs proc

I found the following:
http://innig.net/software/ruby/closures-in-ruby.rb
to be an interesting read on the different flavors of closures in
ruby; I think it takes into account some of the 1.9 changes, but it
may be slightly outdated...

-P

On 2/5/07, Minkoo Seo <minkoo.seo@gmail.com> wrote:
> On Feb 5, 4:37 am, Jim Weirich <j...@weirichhouse.org> wrote:
> > Minkoo Seo wrote:
> > > [...]
> > > The secondis that lambda returns as we expect, i.e., it
> > > returns value, while Proc.new does not.
> >
> > lambda and Proc.new do handle the return statement in different ways.
> > Return in lambda returns from the lambda, treating the lambda as an
> > anonymous function.
> >
> > Return in Proc.new returns from the enclosing method, treating the block
> > as an inline piece of code.
> >
> > The Proc.new behavior is useful where the block is simply a bit the
> > algorithm.  For example:
> >
>
> I guess the following block (do |item| ... end)
>
> >   def member?(target, list)
> >     list.each do |item|
> >        return true if target == item
> >     end
> >     false
> >   end
> > The explicit return should return from the member? method, not just from
> > the loop.
> >
> > -- Jim Weirich
>
> is block and not a proc.
>
> AFAIK, block is not converted to proc unless the block is captured by
> parameter like &blk. Am I wrong?
>
> Sincerely,
> Minkoo Seo
>
>
>