Re: Moose and default values

[tobyink]

I wrote PerlX::Maybe precisely for this purpose!

use v5.14;
use strict;
use warnings;

use PerlX::Maybe;

package Foo {
    use Moose;
    has foo => (is => 'ro', default => 'whatever');
}

my $value = 'hello';
print Foo->new(maybe foo => $value)->dump;

$value = undef;
print Foo->new(maybe foo => $value)->dump;

As you can see, the maybe keyword is applied at the "consumer side" - i.e. in the code that is using the class.

Within the class itself, you could try MooseX::UndefTolerant though that has a major caveat listed in the documentation!

[Ovid]

That is a lovely little module!

[morgon]

Nice, but why does it live in "PerlX" and not in "Moose" or "MooseX"?

[choroba]

Probably you can use it outside Moose, too.

[tobyink]

Indeed; it has no ties to Moose. It's simply a function that takes a list and returns a (possibly smaller) list. While it's handy to use it with Moose/Mouse/Moo constructors, it can be used with any functions that take a list of key-value pairs that you want to filter out undefs from.