CODEWITHSUNDEEP
perlmoo
Dallaylaen
Dallaylaen

Reputation: 5318

Readonly mutators with Moo

I'd like to have an immutable objects with modifiable fields, so that $foo->bar() returns the bar of foo, and $foo->bar(42) returns a new object with bar set to 42, leaving $foo intact.

Of course, I can do that with Moo[se]:

package Foo;
use Moo;

has bar => is => 'lazy', builder => sub { 0 };
around bar => sub {
    my ($orig, $self, $set) = @_;
    if (@_ < 3) {
        return $orig->($self);
    } else {
        return (ref $self)->new( %$self, bar => $set );
    }
};

But this is a bit tedious, so is there a module to add accessors with such signatures?

Upvotes: 3

Views: 88

Answers (0)

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