use strict;
use warnings;

use 5.10.0;

use Devel::Examine::Subs;

my $des = Devel::Examine::Subs->new(file => 'test.pl');

my $subs = $des->objects;

for my $sub (@$subs){
    say $sub->name;
    say "------";
    say $_ for @{ $sub->code };
    say "\n";
}

##</code><code>##

use warnings;
use strict;

three(5);

sub three {
    return two(shift);
}
sub two {
    return one(_helper(shift));
}
sub one {
    my $num = calc(shift);
    display($num);
}
sub calc {
    my $num = shift;
    return $num ** 3;
}
sub display {
    my $num = shift;
    print "$num\n";
}
sub _helper {
    my $num = shift;
    return ++$num;
}

##</code><code>##

spek@scelia ~/scratch $ perl des.pl
display
------
sub display {
    my $num = shift;
    print "$num\n";
}


two
------
sub two {
    return one(_helper(shift));
}


three
------
sub three {
    return two(shift);
}


one
------
sub one {
    my $num = calc(shift);
    display($num);
}


calc
------
sub calc {
    my $num = shift;
    return $num ** 3;
}


_helper
------
sub _helper {
    my $num = shift;
    return ++$num;
}