@mixin deprecate($subject, $instead: false) {
  @warn "\"#{$subject}\" DEPRECATED!#{if($instead, " Use instead: \"#{$instead}\"", '')}";
}

@function isset($v) {
  @return $v != none and $v != false;
}

@function complex-isset($list, $l: length($list)) {
  $i: 1;
  @while $i <= $l and isset(nth($list, $i)) {
    $i: $i + 1;
  }
  @return $i > $l;
}

@function list-rtrim($list, $count: 1) {
  $r: ();
  $l: length($list) - $count;
  $i: 1;
  @while $i <= $l {
    $r: append($r, nth($list, $i));
    $i: $i + 1;
  }
  @return $r;
}

@function complex-list($params) {
  $l: length($params);
  @if $l > 1 and nth($params, $l) == !important {
    $params: list-rtrim($params);
    $l: $l - 1;
  }
  @if $l < 4 {
    @if $l < 3 {
      $params: join($params, nth($params, 1));
    }
    @if $l > 1 {
      $params: join($params, nth($params, 2));
    } @else {
      $params: join($params, $params);
    }
  }
  @return $params;
}

@mixin complex-property($property, $params, $complex-params: false) {
  @if isset($params) {
    $l: length($params);
    @if $l == 1 or complex-isset($params) {
      #{$property}: $params;
    } @else {
      @if $l < 4 {
        $params: if(length($complex-params) >= 4, $complex-params, complex-list($params));
      }
      $i: 0;
      @each $side in top, right, bottom, left {
        $i: $i + 1;
        $p: nth($params, $i);
        @if isset($p) {
          #{$property}-#{$side}: $p;
        }
      }
    }
  }
}

@function strip-px($v) {
  @return if(unit($v) == "px", $v / 1px, $v);
}

@function list-to-string($list, $separator: "") {
  $result: "";
  $first: true;
  @each $cut in $list {
    @if $first {
      $first: false;
      $result: $cut;
    } @else {
      $result: "#{$result}#{$separator}#{$cut}"
    }
  }
  @return $result;
}

@function change-separator($list, $separator: comma) {
  $result: ();
  @each $value in $list {
    $result: append($result, $value, $separator);
  }
  @return $result;
}

@function compact-list($list, $separator: comma) {
  $result: ();
  @each $value in $list {
    @if isset($value) {
      $result: append($result, $value, $separator);
    }
  }
  @return $result;
}

@function hack-ie8($params) {
  @return unquote("#{$params}\0/");
}

@function contains($list, $var) {
  @each $item in $list { @if $item == $var { @return true; } }
  @return false;
}

@function find-typed-item($list, $type, $default: false) {
  @each $item in $list { @if type-of($item) == $type { @return $item; } }
  @return $default;
}

@function find-color($list, $default: false) {
  @return find-typed-item($list, color, $default);
}