in reply to Re: Module vs Singleton
in thread Module vs Singleton

What you have explained here clears my understanding.

Actually, I had searched around and found Class::Singleton and had followed the documentation in that to work with the singleton objects. I was deriving from Class::Singleton. What you have explained is perhaps a simpler way of doing it without requiring the inheritance.

Also, it had never occurred to me that I could use modules for some of these instead of Singletons.

For example, if I had a set of utility functions, I created a Singleton class for it where a module perhaps would have been more appropriate.

It works. But perhaps it is not the right way and less efficient. Should I go back to clean this up and convert some of the Singletons to modules?

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Re^3: Module vs Singleton
by Khen1950fx (Canon) on Jul 16, 2011 at 06:43 UTC
    There's nothing wrong with singletons. This would be a good time to explore Moose, especially MooseX::Singleton. Following up on Anonymous Monk's "new", here's what I tried: 
    
package Foo;
use MooseX::Singleton;

has stuff => (
    is      => 'rw',
    isa     => 'HashRef[Str]',
    default => sub { { default => 'new' } },
);

package main;

my $instance = Foo->instance;
my $same     = Foo->instance;

use Data::Dumper::Concise;
print Dumper($same);

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Re^3: Module vs Singleton
by locked_user sundialsvc4 (Abbot) on Jul 16, 2011 at 12:03 UTC

    Oh, no, no ... if you have found a CPAN module to do what you are looking for, I am always in favor of going that route, because doing so usually gives you a more-robust and well-thought-out solution with less work.   Those CPAN contributors are gooood ...

    Nevermind any concerns for the computer’s “efficiency.”   (At however-many billion operations per second, no one can hear you scream ...)   Rather, think only about your own.   What is the easiest and most reliable to build ... the most serviceable and maintainable ... the most obvious, both now and six months from now when your own code has become the work of a perfect stranger.   (How soon we forget, especially as we get old... aww, forget it...)   ;-)   If you have already put your hand to the plow, it’s rarely a good idea to look back.

    You will soon hear around here this familiar mantra:   TMTOWTDI.™   (a.k.a. “Tim Toady.”)   And you will soon know why we say it.

      I do appreciate the knowledge shared here. I have much reading to do. I will keep in mind the advice received.

      Thank you.

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