Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.9)
// Compass (v1.0.0.alpha.20)
// ----

/**
 * Base font size
 *
 * @type Number
 */
$base-font-size: 16px !default;

/**
 * Base spacing unit
 *
 * @type Number
 */
$base-spacing-unit: 1rem !default;

/**
 * Shortcut for half the base spacing unit
 * 
 * @requires {variable} base-spacing-unit
 *
 * @type Number
 */
$half-spacing-unit: $base-spacing-unit / 2;

/**
 * Defines whether rem values should have a px fallback.
 *
 * @type Bool
 */
$rem-fallback: true !default;
 
/**
 * Spacing mixin
 *
 * @access private
 *
 * @requires {variable} rem-fallback
 * @requires {variable} base-font-size
 *
 * @type Number
 */
@mixin spacing($spacing-type, $args) {
  @if $rem-fallback {
    $fallback: ();
    $regular: ();
  
    @each $value in $args {
      @if type-of($value) == "number" and unit($value) == "px" {
        $fallback: append($fallback, $value);
        $regular: append($regular, $value / $base-font-size * 1rem);
      }
      
      @else if type-of($value) == "number" and unit($value) == "rem" {
        $fallback: append($fallback, $value / 1rem * $base-font-size);
        $regular: append($regular, $value);
      }
      
      @else {
        $fallback: append($fallback, $value);
        $regular: append($regular, $value);
      }
    }
  
    #{$spacing-type}: $fallback;
    #{$spacing-type}: $regular;
  }
  
  @else {
    #{$spacing-type}: $args;
  }
}

/**
 * Short cut for `spacing(padding, ...)`
 *
 * @requires {mixin} spacing
 */
@mixin padding($args) {
  @include spacing(padding, $args);
}

/**
 * Short cut for `spacing(margin, ...)`
 *
 * @requires {mixin} spacing
 */
@mixin margin($args) {
  @include spacing(margin, $args);
}

// Demo
el {
  @include padding(0 $half-spacing-unit auto);
}

SassMeister-output.css

/**
 * Base font size
 *
 * @type Number
 */
/**
 * Base spacing unit
 *
 * @type Number
 */
/**
 * Shortcut for half the base spacing unit
 * 
 * @requires {variable} base-spacing-unit
 *
 * @type Number
 */
/**
 * Defines whether rem values should have a px fallback.
 *
 * @type Bool
 */
/**
 * Spacing mixin
 *
 * @access private
 *
 * @requires {variable} rem-fallback
 * @requires {variable} base-font-size
 *
 * @type Number
 */
/**
 * Short cut for `spacing(padding, ...)`
 *
 * @requires {mixin} spacing
 */
/**
 * Short cut for `spacing(margin, ...)`
 *
 * @requires {mixin} spacing
 */
el {
  padding: 0 8px auto;
  padding: 0 0.5rem auto;
}