Sass list utilities

_list-utilities.scss

/**
 * Search a list ($haystack) for a list of values ($needles). Returns
 * true if any of the $needles are found in the $haystack, or false if not found.
 *
* Example:
*  list-key-exists((value1 value2 value3), 'value1') => true
*  list-key-exists((value1 value2 value3), (thing, value1)) => true
*  list-key-exists((value1 value2 value3), 'nothere') => false
*/
@function list-key-exists($haystack, $needles) {
    @each $needles-item in $needles {
        @each $haystack-item in $haystack {
            @if $needles-item == $haystack-item {
                @return true;
            }
        }
    }

    @return false;
}

/**
 * Search a list of lists ($haystack) for value ($needle) at a given position
 * ($offset). Returns that item in the list, or false if not found.
 *
 * Example:
 *  list-key-search(((key1 value1), (key2 value2)), 'key1', 1) => (key1 value1)
 */
@function list-key-search($haystack, $needle, $offset: 1) {
    @each $haystack-item in $haystack {
        @if $needle == nth($haystack-item, $offset) {
            @return $haystack-item;
        }
    }

    @return false;
}