test-mop-construction.pl

#!/usr/bin/env perl

use v5.14;
use mop;
use Data::Printer;

class Foo {
    has $!foo is ro;

    method new($class: $foo) {
        say "# Foo::new($foo)";
        $class->next::method(foo => $foo);
    }

    submethod BUILD($args) {
        say "# Foo::BUILD(", p($args), ")";
        $!foo = $args->{foo} if exists $args->{foo};
    }
}

class Bar extends Foo {
    has $!bar is ro;

    method new($class: $foo, $bar) {
        say "# Bar::new($foo, $bar)";
        $class->next::method($foo);
    }

    submethod BUILD($args) {
        say "# Bar::BUILD(", p($args), ")";
        $!bar = $args->{bar} if exists $args->{bar};
    }
}

my $bar = Bar->new(10, 42);
p mop::dump_object($bar);

Output:

# Bar::new(10, 42)
# Foo::new(10)
# Foo::BUILD(\ {
    foo   10
})
# Bar::BUILD(\ {
    foo   10
})
\ {
    $!bar       undef,
    __CLASS__   "Bar",
    $!foo       10,
    __ID__      24118488,
    __SELF__    Bar  {
        public methods (0)
        private methods (0)
        internals: undef
    }
}

What should change in order to intialize Bar object properly?