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

@if $int%2 == 0   {
  @return true;
}

@return false;

}

// Checks if an element belongs to a list @function belongs-to($tested-item, $list) {

@each $item in $list {
  @if $item == $tested-item {
    @return true;
  }
}

@return false;

}

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

@if belongs-to(table, $query) or belongs-to(block, $query) or belongs-to(inline-block, $query) or belongs-to(inline, $query) {
  @return true;
}

@return false;

}

// 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;
}

@else {
  @return $grid-columns;
}

}

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

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

@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;
}

@else {
  @return $parent-columns;
}

}

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

$transparent: rgba(0,0,0,0);

$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: nil;

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

@return $direction;

}

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

$direction: nil;

@if $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;

}