An Idea

gistfile1.pl

#!/usr/bin/perl
use Modern::Perl;
use Coro;

sub do_a_thing {
    my @args = @_;
    my $cb = pop @args;
    async {
        for my $thing (@args) {
            say "Thing $thing";
            cede;
        }
        $cb->('done');
    };
}

sub wait_call {
    my ($sub, @args) = @_;
    $sub->(@args, Coro::rouse_cb);
    return Coro::rouse_wait;
}

async {
    say 'this is async';
    cede;
    say 'still async';
};

my @stuff = wait_call \&do_a_thing, 1, 2, 3;
say @stuff;