font-face($name, $file = $name, $folder = $file, $weight = null, $style = null, $exts = eot woff2 woff ttf svg)
  $src = null
  $extmods = {eot: "?", svg: "#" + replace(" ", "_", $name)}
  $formats = {eot: "embedded-opentype", otf: "opentype", ttf: "truetype"}

  for $ext in $exts
    $extmod = $ext
    $format = $ext
    if $ext in $extmods
      $extmod = $ext + $extmods[$ext]
    if $ext in $formats
      $format = $formats[$ext]

    $path = pathjoin($folder, ($file + '.' + $extmod))
    $fontdecl = font($path) + ' format("' + $format + '")'

    if $src == null
      $src = $fontdecl
    else
      $src = join(', ', $src, $fontdecl)



  @font-face
    font-family: $name

    if $weight
      font-weight: $weight
      
    if $style
      font-style: $style

    if index($exts, eot)
      $path = pathjoin($folder, ($file + '.eot'))
      $fontdecl = font($path)
      src: unquote($fontdecl)

    src: unquote($src)