Collections

Raku has both mutable and immutable containers of various sorts. Here are some of the most common ones:

Mutable

# Array
my @array = 1,2,3;
@array.push: 4,5,6;

# Hash
my %hash = 'a' => 1, 'b' => 2;
%hash<c d> = 3,4;
%hash.push: 'e' => 5, 'f' => 6;

# SetHash
my $s = SetHash.new: <a b c>;
$s ∪= <d e f>;

# BagHash
my $b = BagHash.new: <b a k l a v a>;
$b ⊎= <a b c>;

Immutable

# List
my @list := 1,2,3;
my @newlist := |@list, 4,5,6; # |@list will slip @list into the surrounding list instead of creating a list of lists

# Set
my $set = set <a b c>;
my $newset = $set ∪ <d e f>;

# Bag
my $bag = bag <b a k l a v a>;
my $newbag = $bag ⊎ <b e e f>;

Pair list (cons list)

my $tail = d => e => f => Nil;
my $new = a => b => c => $tail;

P6opaque object (immutable in structure)

class Something { has $.foo; has $.bar };
my $obj = Something.new: foo => 1, bar => 2;
my $newobj = $obj but role { has $.baz = 3 } # anonymous mixin