Compass sprite generator with before pseudo class

sprite-before-generator

$files: sprite-map("file/*.png");
%file-sprite {
    display: inline-block;
    margin-right: 8px;
    @include sprite-dimensions($files, 'doc');
    background: sprite-url($files) no-repeat;
    content: '';
    vertical-align: middle;
}

@each $i in sprite_names($files) {
    .file--#{$i}:before {
        @extend %file-sprite;
        background-position: sprite-position($files, $i);
    }
}