/ 
lexicals-0.16
River stage one • 1 direct dependent • 3 total dependents
/ lexicals

NAME

lexicals - Get a hash of your current 'my' variables

SYNOPSIS

use Template::Toolkit::Simple;
use lexicals;

sub mail {
    my $self = shift;
    my $name = 'Mr. ' . $self->get_name;
    my $address = $self->fetch_address($name);
    my $stamp = Postage::Stamp->new(0.44);
    my $envelope = tt->render('envelope', lexicals);
}

DESCRIPTION

Python has a builtin function called `locals()` that returns the lexically scoped variables in a name/value mapping. This is a very useful idiom. Instead of needing to create a hash like this:

my $hash = {
    foo => $foo,
    bar => $bar,
};

Just say:

my $hash = lexicals;

Assuming you have a $foo and $bar defined, you get the same thing.

The `lexicals` module exports a function called `lexicals`. This function returns the lexicals as a hash reference (in scalar or list context).

ARRAYS AND HASHES

The above examples deal with lexical scalars. You can also get back lexical arrays and hashes. Note: since there is no sigil to tell scalars from arrays from hashes, you can't get back a scalar and an array or hash of the same name. In this case, SCALAR beats HASH beats ARRAY. Why? Because I said so! (Actually I just used the sort order of the sigils).

sub foo {
    my %h = ( O => 'HAI' );
    my @a = [ qw( foo bar baz ) ];
    my $s = 42;
    my %x = ( O => 'HAI' );
    my @x = [ qw( foo bar baz ) ];
    my $x = 42;
    print Dump lexicals;
}

would yield:

---
a:
- foo
- bar
- baz
h:
  O: HAI
s: 42
x: 42

NOTE

The lexicals function only reports the lexical variables variables that were defined before where it gets called.

DEBUGGING TRICK

This could be a handy idiom for debugging:

use XXX;

sub foo {
    ...
    XXX lexicals;     # See your lexicals in the nude.
    ...
}

SEE ALSO

AUTHOR

Ingy döt Net <ingy@ingy.net>

COPYRIGHT AND LICENSE

Copyright (c) 2011. Ingy döt Net.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

See http://www.perl.com/perl/misc/Artistic.html