Generated by SassMeister.com.

SassMeister-input-HTML.html

<div class="Bar">Bar</div>
<div class="Baz">Baz</div>
<div class="Qux">
  Qux
  <div class="Qux_Sub">Qux_Sub</div>
</div>

SassMeister-input.sass

// ----
// Sass (v3.3.3)
// Compass (v1.0.0.alpha.18)
// ----

=extend-variants($module_name, $variants...)
  @each $variant in $variants
    @if type_of($variant) == "list"
      $variant: #{nth($variant, 1)}--#{nth($variant, 2)}
    @extend %#{$module_name}-#{$variant}

=extend($module_name, $variants...)
  @extend %#{$module_name}
  +extend-variants($module_name, $variants...)


=Bat($sel, $vars...)
  .#{ $sel }
    color: red
    @if index($vars, foo)
      color: blue
=Bat_Sub($sel, $vars...)
  .#{ nth($sel,1) }_#{ nth($sel,2) }
    border: 1px solid red
    @if index($vars, foo)
      border-color: yellow
  .#{ nth($sel,1) }.-foo .#{ nth($sel,1) }_#{ nth($sel,2) }
    border-color: green



%Component
  font:
    size: 20px
    family: Helvetica
  &_SubComponent
    border: 1px solid black
  &-foo
    color: red
  &-foo &_SubComponent
    border-color: red


.Bar
  +extend(Component)

.Baz
  +extend(Component, foo)

.Qux
  +extend(Component)
  &.-bar
    +extend-variants(Component, foo)

.Qux_Sub
  +extend(Component_SubComponent)

+Bat(Zonk)
+Bat(Zorp, foo)
+Bat_Sub(Zorp C)
// can't remap variants

SassMeister-output.css

.Bar, .Baz, .Qux {
  font-size: 20px;
  font-family: Helvetica;
}
.Qux_Sub {
  border: 1px solid black;
}
.Baz, .Qux.-bar {
  color: red;
}
.Baz .Qux_Sub, .Qux.-bar .Qux_Sub {
  border-color: red;
}

.Zonk {
  color: red;
}

.Zorp {
  color: red;
  color: blue;
}

.Zorp_C {
  border: 1px solid red;
}

.Zorp.-foo .Zorp_C {
  border-color: green;
}

SassMeister-rendered.html

<div class="Bar">Bar</div>
<div class="Baz">Baz</div>
<div class="Qux">
  Qux
  <div class="Qux_Sub">Qux_Sub</div>
</div>