From: Robert Klemme <shortcutter@...>
Date: 2005-08-31T23:20:54+09:00
Subject: Re: Semantics of << and <<-

2005/8/31, Robert Klemme <shortcutter@googlemail.com>:
> 2005/8/31, Anders H�ckersten <chucky@dtek.chalmers.se>:
> > Hi,
> > I recently joined this list, so please forgive me if this question has
> > been asked recently. I am wondering about the precise semantics of <<
> > and <<-. "Programming Ruby"[1] and the pseudo-BNFs[2][3] say that you
> > can use a quoted string after <<. As I see it, this means I should be
> > able to able to use the #{expr} construct inside this string, like this:
> > print <<"#{2+2}"
> > foobar
> > #{4}
> >
> > This is, however, not the way my installation of Ruby (1.8.1) works.
> > What I am wondering is, is this the expected behaviour and are both the
> > book and the pseudo-BNFs wrong, or is this some form of bug in the
> > interpreter?
> 
> My guess would be that it's an omission in the documentation. I don't
> think you can do interpolation in the string.  Basically it's not a
> Ruby string but an idendifier and the quotation announces differnt
> behaviro. After all, what do you gain by a computed terminator of a
> here document?  I don't think that's useful.
> 
> See http://www.ruby-doc.org/docs/ProgrammingRuby/#UD

Here's the correct link:

http://www.ruby-doc.org/docs/ProgrammingRuby/html/language.html#UD