From: Robert Klemme <bob.news@...>
Date: 2004-12-02T21:27:43+09:00
Subject: Re: singleton methods : when are they not permitted?


"Brian Schr�der" <ruby@brian-schroeder.de> schrieb im Newsbeitrag
news:20041202123358.431849d2@black.wg...
> On Thu, 2 Dec 2004 19:12:43 +0900
> "Robert Klemme" <bob.news@gmx.net> wrote:
>
>
> > I prefer to view a literal as a special kind of expression that yields
an
> > instance on each execution.  Whether this is always the same instance
(as
> > for symbols, Fixnum and surprisingly also for Bignum and Regexp) or
> > whether it's a different instance (as for strings, arrays and hashes)
> > depends on the literal.
>
> That regexps are always the same surprised me also, but it is nice. So
it is
> not optimization to extract a regexp into a constant instead of writing
it in
> the loop.

Except you need some interpolation. :-)

> (Btw: Always when I'm trying to optimze something in ruby, it gets
slower. Ruby
> follows exactly my mindset when programming, and when I try to change my
mind
> on how the computer actually works it out, I'm running in the wrong
> direction.;)

:-)

> irb(main):005:0> 2.times do |i| puts /abc/.id end
> 538420744
> 538420744
> => 2
>
> But it can't always be true
>
> irb(main):006:0> 2.times do |i| puts /abc#{i}/.id end
> 538396754
> 538396704
> => 2
>
> Or maybe one should clarify it such, that a regexp with interpolation is
no
> longer a literal.

But

>> 2.times do |i| puts /abc#{i}/o.id end
135012888
135012888
=> 2

Note the usage of flag "o".

Kind regards

    robert