sub build_lazy
{
    my ($var, $callback, @params) = @_;

    
    eval <<__EVAL__;
{
    my \$$var;
    sub $var {
        \\\$var = $callback->(@params) unless defined \$$var;
        \$$var;
    };
}
__EVAL__
}

# Later ...

build_lazy( 'dbh', \&build_dbh, @dbh_params );
build_lazy( 'foo', \&build_foo );

[download]

Of course, you might want some dwimmery for hashes vs. arrays vs. scalars, unless you're ok with everything as a reference. I would be, but that's just me. And, you might want to throw BEGIN or CHECK around the calls to build_lazy(), but that's probably overkill.

------
We are the carpenters and bricklayers of the Information Age.

Then there are Damian modules.... *sigh* ... that's not about being less-lazy -- that's about being on some really good drugs -- you know, there is no spoon. - flyingmoose

I shouldn't have to say this, but any code, unless otherwise stated, is untested

In reply to Re^3: Does there exist a CPAN module for lazily initialized variables? by dragonchild
in thread Does there exist a CPAN module for lazily initialized variables? by jryan

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