// Not function for Libsass compatibility // github.com/sass/libsass/issues/368 @function is-not($value) {

@return if($value, false, true);

}

// Checks if a number is even @function is-even($int) {

@return $int % 2 == 0;

}

// Checks if an element belongs to a list or not @function belongs-to($tested-item, $list) {

@return is-not(not-belongs-to($tested-item, $list));

}

@function not-belongs-to($tested-item, $list) {

@return is-not(index($list, $tested-item));

}

// Contains display value @function contains-display-value($query) {

@return belongs-to(table, $query)
     or belongs-to(block, $query)
     or belongs-to(inline-block, $query)
     or belongs-to(inline, $query);

}

// Parses the first argument of span-columns() @function container-span($span: $span) {

@if length($span) == 3 {
  $container-columns: nth($span, 3);
  @return $container-columns;
} @else if length($span) == 2 {
  $container-columns: nth($span, 2);
  @return $container-columns;
}

@return $grid-columns;

}

@function container-shift($shift: $shift) {

$parent-columns: $grid-columns !default !global;

@if length($shift) == 3 {
  $container-columns: nth($shift, 3);
  @return $container-columns;
} @else if length($shift) == 2 {
  $container-columns: nth($shift, 2);
  @return $container-columns;
}

@return $parent-columns;

}

// Generates a striped background @function gradient-stops($grid-columns, $color: $visual-grid-color) {

$transparent: transparent;

$column-width: flex-grid(1, $grid-columns);
$gutter-width: flex-gutter($grid-columns);
$column-offset: $column-width;

$values: ($transparent 0, $color 0);

@for $i from 1 to $grid-columns*2 {
  @if is-even($i) {
    $values: append($values, $transparent $column-offset, comma);
    $values: append($values, $color $column-offset, comma);
    $column-offset: $column-offset + $column-width;
  } @else {
    $values: append($values, $color $column-offset, comma);
    $values: append($values, $transparent $column-offset, comma);
    $column-offset: $column-offset + $gutter-width;
  }
}

@return $values;

}

// Layout direction @function get-direction($layout, $default) {

$direction: null;

@if to-upper-case($layout) == "LTR" or to-upper-case($layout) == "RTL" {
  $direction: direction-from-layout($layout);
} @else {
  $direction: direction-from-layout($default);
}

@return $direction;

}

@function direction-from-layout($layout) {

$direction: null;

@if to-upper-case($layout) == "LTR" {
  $direction: right;
} @else {
  $direction: left;
}

@return $direction;

}

@function get-opposite-direction($direction) {

$opposite-direction: left;

@if $direction == "left" {
  $opposite-direction: right;
}

@return $opposite-direction;

}