@use 'sass:list';

/**
 * Extracts a slice of a given list.
 *
 * @param    {list}      $list           The input list.
 * @param    {number}    $start-at       Starting index (inclusive).
 * @param    {number}    $end-at [-1]    Ending index (inclusive).
 *
 * @return   {list}      The slice of the input list.
 */
@function list-slice($list, $start-at, $end-at: -1) {
	$output: ();
	$start: if($start-at < 0, list.length($list) + $start-at + 1, $start-at);
	$end: if($end-at < 0, list.length($list) + $end-at + 1, $end-at);

	@if ($end < $start) {
		@return ();
	}

	@for $i from $start through $end {
		@if ($i >= 1 and $i <= list.length($list)) {
			$output: list.append($output, list.nth($list, $i), list.separator($list));
		}
	}

	@return $output;
}