Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.7)
// Compass (v1.0.0.alpha.18)
// ----

$fonticons: 
  glass '\f000',
  music '\f001',
  star-empty '\f006';


@each $item in $fonticons{
  $name: nth($item, 1);
  $code: nth($item, 2);
  .icon-#{$name}:before,
  .icon-#{$name}-left:before,
  .icon-#{$name}-right:after {
    content: $code;
  }
}

@mixin font-icon($icon-name){
  @each $item in $fonticons{
    $name: nth($item, 1);
    $code: nth($item, 2);
    @if $name == $icon-name{
      content: $code;
    }@else {
      @warn ("icon name not found");
    }
  }
}

.mi-clase:before{
  @extend .icon-music;
}
.mi-otra-clase:after{
  @include font-icon('music');
}

SassMeister-output.css

.icon-glass:before,
.icon-glass-left:before,
.icon-glass-right:after {
  content: "\f000";
}

.icon-music:before, .mi-clase:before,
.icon-music-left:before,
.icon-music-right:after {
  content: "\f001";
}

.icon-star-empty:before,
.icon-star-empty-left:before,
.icon-star-empty-right:after {
  content: "\f006";
}

.mi-otra-clase:after {
  content: "\f001";
}