Dirty script to render the Mandelbrot set to the terminal

mandelbrot.pl6

sub terminal-width(:$default=100) {
    my $width = run('tput', 'cols', :out).out.slurp-rest.trim.Int;
    return $width < $default ?? $default !! $width;
}

sub is-mandelbrot(Complex $z0, int $max=100) {
    my Complex $z = $z0;
    for ^$max -> $n {
        return $n if ($z.abs() > 2e0);
        $z = $z**2 + $z0;
    }
    return $max;
}

my @shades = [" ","░","▒","▓","█"];

sub MAIN(num :$mid-x=-0.4e0, num :$mid-y=0e0, num :$zoom=2e0, int :$width = terminal-width(:default<100>), int :$height=50) {

    for ^$height -> $j {
        my $row = "";
        for ^$width -> $i {
            my num $x = $mid-x - $zoom/2e0 + $zoom*$i/$width;
            my num $y = $mid-y - $zoom/2e0 + $zoom*$j/$height;
            my Complex $z0 = Complex.new($x, $y);
            if $zoom == 2e0 {
                $row ~= @shades[floor(is-mandelbrot($z0,10) / 2.5e0)];
            } else {
                $row ~= @shades[floor(is-mandelbrot($z0) / 25e0)];
            }
        }
        say $row;
    }
}