在Sass中将斜杠添加到CSS类名中

Question

我有这段代码;

@each $viewport, $viewport-val in $viewport-vars {

    // Classes only apply once certain breakpoint is triggered.

    @include media-query(nth($viewport-val, 1)) {

    $_cols: nth($viewport-val, 2);

      @while $_cols > 1 {
        @for $i from 1 through $_cols {
          @if $i == $_cols {
            .pull-#{$viewport}-1/0 {
              $col-width: (100 / $_cols * $i);
              right: (percentage($col-width / 100));
            } 
          } @else {
           .pull-#{$viewport}-#{$i}-#{$_cols} {
              $col-width: (100 / $_cols * $i);
              right: (percentage($col-width / 100));
            } 
          }
        }
        $_cols: $_cols - 1;
      }

    }

  }

我有这行.pull-#{$viewport}-#{$i}-#{$_cols}，我想在类名中添加斜杠，#{$i}/#{$_cols}

不幸的是，这会引发错误，有人知道为什么吗？

乙