say "Insertion Sort

LEGEND:
!   mark to the left of which the array is sorted
|   placeholder for above mark while invariant may be temporarily violated
>   pointer to pair of items that will be swapped if out of order
";

my @list = split "", chomp =$IN;

sub display (@separators) {
    say (join ' ', (@separators ¥ @list,' '));
}
sub swap (@_ is rw) { @_[0,1] = @_[1,0] }

OUTER: for 1..@list.end -> $sorted {
    display (' ' xx $sorted, '!', ' ' xx (1+@list.end-$sorted));

    for reverse (0..$sorted-1) -> $idx {
        display (' ' xx $idx, '>', ' ' xx ($sorted-$idx-1), '|', ' ' xx (@list.elems-$sorted));

        if @list[$idx] gt @list[$idx+1] {
            swap @list[$idx, $idx+1];
        } else {
            next OUTER;
        }
    }
    display (' ' xx $sorted, '|', ' ' xx (1+@list.end-$sorted));
}

display (' ' xx @list.elems, "!");