From: Robert Klemme <bob.news@...>
Date: 2004-10-18T21:44:22+09:00
Subject: Re: [Chocolate Ketchup Dressing] A working Ruby source code filter


"Edgardo Hames" <ehames@gmail.com> schrieb im Newsbeitrag
news:478c16ae041018053737c72bec@mail.gmail.com...
> On Sat, 16 Oct 2004 09:34:28 +0900, Florian Gross <flgr@ccan.de> wrote:
> > Moin!
> >
> > I've implemented a Ruby source code filter for the frequently
requested
> > ".=" operator. (Replace by result of method call)
> >
> > Here's a boring example of how it is used:
> >
> > #!/usr/bin/ruby -rfilter
> > obj = "foobar"
> > obj .= reverse
> > p obj # => "raboof"
>
> Hi, Florian. How does .= differ from bang methods?
> I mean obj.reverse seems to be the same as obj.reverse!

Not quite: the bang method usually saves an intermediate instance *and* it
might have undesirable side effects (if someone else holds a reference to
the instance and doesn't expect it to be modified).  As a consequence,
".=" will work with frozen objects, while bang methods usually don't.  As
usual it's a tradeoff / design decision which of both approaches you use.

Kind regards

    robert