Generated by SassMeister.com.

SassMeister-input.sass

// ----
// Sass (v3.3.0.rc.1)
// Compass (v0.13.alpha.10)
// ----

@import "compass"

@mixin arrow( $width, $color, $position )
  $opposite: opposite-position($position)
  
  position: absolute
  border: $width solid transparent
  border-#{$opposite}-color: $color
  left: 50%
  margin-left: -$width/2
  #{$position}: -$width

.test
  @include arrow(10px,black,top)

SassMeister-output.css

.test {
  position: absolute;
  border: 10px solid transparent;
  border-bottom-color: black;
  left: 50%;
  margin-left: -5px;
  top: -10px;
}