Why would a red painter be interested in learning blue? Could someone
who only knew one color honestly claim to be a painter to begin with?
Thank you for the opportunity to clarify this.
We (speaking as one who uses Perl as his primary language) all know
and use other languages all day, every day -- like SQL, HTML, XML,
CSS, JavaScript, and so on. Not that these are Turing complete, but
they ARE languages that you must learn in order to use.
Also, most of us have used and continue to use other 'big' languages,
like C, or Java. I came to Perl from Java, and actually revert to Java
when I work on a big project. Java allows you to organize your code in
classes, with attributes and methods, and for a big project with lots
of classes it results in a product much easier to understand than
Perl. It's not that you /couldn't/ write a big app in Perl, it's just
that most use Java, or C++, or C#.
Ruby has a saying that it's Perl done right. Having used a little
Ruby, I can see how this saying makes sense. However, Perl is a more
powerful language than Ruby (my opinion), and a Perlista who learns
Ruby for the purpose of replacing his language of choice with Ruby is
moving in the wrong direction. IOW, it would be like a sports driver
giving up a Porsche for a VW in order to go faster.
I fully agree with you point about learning other languages. I have
been studying Common Lisp and Erlang, and have begun to rewrite some
of my Perl scripts in Lisp. Also, this year (2011) I have been
introduced to Prolog and R, and have placed both of these languages
near the top of my to-learn list. Prolog especially -- it's not a
replacement for Perl, but it will do different things, and you can
certainly use Perl and Prolog in tandem, the first to produce the
facts and rules from a data file and the second to search for your
results.
CC.