dot-equals-grep.p6

use v6;

use Test;

sub expanded-version {
    my @values = <foo bar baz>;
    my %possible-values = (
        foo => (1..9).list,
        bar => (2..9).list,
        baz => (3..9).list,
    );

    for @values -> $value {
        my @matches = %possible-values{$value}.grep: {
            $_ %% 2
        };
        %possible-values{$value} = @matches;
    }

    is(%possible-values<foo>, [2, 4, 6, 8]);
}

sub dot-equals-version {
    my @values = <foo bar baz>;
    my %possible-values = (
        foo => (1..9).list,
        bar => (2..9).list,
        baz => (3..9).list,
    );

    for @values -> $value {
        %possible-values{$value} .= grep: {
            $_ %% 2
        };
    }

    say %possible-values.perl;
    is(%possible-values<foo>, [2, 4, 6, 8]);
}

plan 2;
expanded-version;
dot-equals-version;

output

1..2
ok 1 -
("foo" => ().list.item, "bar" => ().list.item, "baz" => ().list.item).hash
not ok 2 -
#      got: ''
# expected: '2 4 6 8'
# Looks like you failed 1 tests of 2