Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.8)
// Compass (v1.0.0.alpha.19)
// ----

// Sass: Type hinting with function.
// by https://twitter.com/phize

// Dependency Injection: @content injection
// http://sassmeister.com/gist/3686b8eb3462fef52013

// Dependency Injection: Mixin injection
// http://sassmeister.com/gist/5122325c0c29889b91c3

// Polymorphic components:
// http://sassmeister.com/gist/1a10ec1c1556dfd3d6b5

@function is-spacing($value) {
  @if length($value) >= 1 and length($value) <= 4 {
      @return true;
  }

  // You may also test the unit of value.

  @return false;
}

// spacing pseudo-type
@function spacing($value) {
  @if not is-spacing($value) {
      @warn "throw an exception here.";
  }

  @return $value;
}

@mixin margin($value) {
  margin: spacing(10px);
}

.margin {
  @include margin( spacing(10px) );
  
  // You may also crate and use px():
  // @include margin( spacing( px(10) ) );
}

SassMeister-output.css

.margin {
  margin: 10px;
}