use Perl

"Persistence" implies that data will be saved and loaded from disk, to a database, or some other persistent storage. That's not what the module does, so I think it needs a new name.

Lexical::Persistence objects are closures that make the values of lexical variables stick (or persist) in everything they call. In the following example, the Lexical::Persistence object makes sure that getter()'s version of $x contains the value stored by setter().

use Lexical::Persistence;

my $lp = Lexical::Persistence->new();
$lp->call(\&setter);
$lp->call(\&getter);

sub setter { my $x = "some value" }
sub getter { print my $x, "\n" }

Lexical::Persistence's closures are objects. Programs may examine and manipulate their contents between calls. The following code displays something like this:

My mind is going. I can feel it.
My is going. I can feel it.
My is going. I feel it.
My going. I feel it.
My going. I feel
My I feel
My I
My

Here's the example:

use Lexical::Persistence;

my $lp = Lexical::Persistence->new();
$lp->set_context(
    _ => {
        '@mind' => [qw(My mind is going. I can feel it.)]
    }
);

while (1) {
    $lp->call(\&display);
    my $mind = $lp->get_context("_")->{'@mind'};
    splice @$mind, rand(@$mind), 1;
    last unless @$mind;
}

sub display {
    my @mind;
    print "@mind\n";
}

So, what would be a better name for this module?