loop-in-reverse.less

.generate-something(4);

.generate-something(@i) when (@i > 0) {
    // just invoke next iteration *before* styles
    // so the styles output when the loop is unwinded
    // and the whole thing works in reverse:
    .generate-something((@i - 1));
    .something-@{i} {
        left: (@i * 1%);
    }
}