From: Conrad Schneiker <schneiker@...>
Date: 2000-03-25T12:35:20-06:00
Subject: [ruby-talk:02161] Re: ARGF vs. $<

From: Dave Thomas <Dave@thomases.com>

> schneik@us.ibm.com writes:
>
> > Matz wrote:
> > >     on 00/03/23, Dave Thomas <Dave@thomases.com> writes:
> > >
> > > |Apart from the naming convention, is there a reason that ARGF is
> > > |documented as a global constant and $< as a global variable? They
both
> > > |reference the same object, and effectively have the same semantics.
Am
> > > |I missing something subtle here?
> > >
> > > They are same in semantics, but syntactically, $< is a read-only
> > > special variable, and ARGF is a constant.  In reference manual, I
> > > cannot ignore syntactical difference.
> >
> > I don't know if Dave also wants to include the following in his
> > documentation, but in English.rb there is also:
> >
> >     alias $DEFAULT_INPUT           $<
>
> I'm documenting English.rb in the section on library files, although
> matz dislikes it as a Perl-ism ;-)

Very strange that this rather uncharacteristic add-on to make Perl more
readable and more self-documenting would be regarded as a Perl-ism. Besides,
IIRC, some of these items were originally from awk. :-)

I would have preferred a more terse/compact/abbreviated set of names instead
of symbols and aliases. For example, $DEF_IN would seem to be the
Aristotelian Ruby mean between the Perl-ish $< and the Cobol-ish
$DEFAULT_INPUT. Maybe someday if Ruby makes a Perl4 to Perl5 or Python 1.6
to Python 3000 type of transition in a few years, then.... :-)

> However, I'd forgotten to cross
> reference that from my (overly long) table of predefined variables, so
> thanks for the timely reminder.

You're welcome,
Conrad