$ cat struct.pm
package struct;
use strict;
use warnings;
sub import
{
shift;
my ( $name, $fields ) = @_;
my $caller = caller;
my %subs;
foreach ( 0 .. $#$fields ) {
my $idx = $_;
$subs{$fields->[$idx]} = sub :lvalue { shift->[$idx] };
}
my $pkg = "struct::impl::$name";
no strict 'refs';
*{$pkg."::$_"} = $subs{$_} for keys %subs;
*{$caller."::$name"} = sub { bless [ @_ ], $pkg };
}
1;
$ perl
use struct Point => [qw( x y )];
my $p = Point(10,20);
printf "Point is at (%d,%d)\n", $p->x, $p->y;
$p->x = 30;
printf "Point is now at (%d,%d)\n", $p->x, $p->y;
$p->z = 40;
__END__
Point is at (10,20)
Point is now at (30,20)
Can't locate object method "z" via package "struct::impl::Point" at - line 6.
It's specifically and intentionally not an object class. You cannot subclass it. You cannot provide methods. You cannot apply roles or mixins or metaclasses or traits or antlers or whatever else is in fashion this week.
On the other hand, it is tiny, single-file, creates cheap lightweight array-backed structures, uses nothing outside of core. And I defy anyone to even measure its startup overhead with a repeatable benchmark.
It's intended simply to be a slightly nicer way to store internal data structures, where otherwise you might be tempted to abuse a hash, complete with the risk of typoing key names.
Would anyone use this, if it were available?
