Editing Higher-order function (section)

====Raku====
{{further information|Raku (programming language)}}

<syntaxhighlight lang="perl6">
sub twice(Callable:D $f) {
    return sub { $f($f($^x)) };
}

sub plusThree(Int:D $i) {
    return $i + 3;
}

my $g = twice(&plusThree);

say $g(7); # 13
</syntaxhighlight>

In Raku, all code objects are closures and therefore can reference inner "lexical" variables from an outer scope because the lexical variable is "closed" inside of the function. Raku also supports "pointy block" syntax for lambda expressions which can be assigned to a variable or invoked anonymously.