Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.2)
// Compass (v1.0.0.alpha.18)
// ----

$state-when--types: (
  'active':  ('&.is--active, &:active, &:hover'),
  'current': ('&.is--current'),
  'visible': ('&.is--visible')
) !global;

@mixin state-when ($states) {
  @each $state in $states {
    $selector: map-get($state-when--types, $state);
    
    #{$selector} {
      @content;
    }
  }
}

.example {
  @include state-when('active') {
    display: block;
  };
}

.example2 {
  $states: 'active', 'current';
  @include state-when($states) {
    background-color: red;
  }
}

SassMeister-output.css

.example.is--active, .example:active, .example:hover {
  display: block;
}

.example2.is--active, .example2:active, .example2:hover {
  background-color: red;
}
.example2.is--current {
  background-color: red;
}