// =============================================================================
// =ALEKSI - PREVIOUS
// =============================================================================
////
//// @group aleksi-lists
//// @author [Yoannis Jamar](https://yoannis.com)

@import "aleksi/general/throw";

// =previous( $list, $value )
// -----------------------------------------------------------------------------
/// Returns the item sitting previous to the given value in alist. If the value
/// is found multiple times, it will use the first one. If the value was not
/// found or is in first position in the list, it will return `null`.
///
/// @param {list} $list - The list in which to search.
/// @param {list} $value - The value to search in `$list`.
///
/// @return {any} - The value sitting next to `$value` in `$list`.
/// @throw Warning if `$value` was not found in `$list`.
/// @throw Warning if `$value` is the first value in `$list`.
///
/// @example scss
///   $foo: next( 'foo' 'bar' 'baz', 'bar');
///     // => 'foo'
///   $bar: next( 'foo' 'bar' 'baz', 'foo');
///     // => null
///   $baz: next( 'foo' 'bar' 'baz', 'wiz');
///     // => null
///
/// @access public
/// @since 0.1.0

@function previous( $list, $value )
{
  $index: index($list, $value);

  @if $index == null {
    @return throw-warning('previous():: #{inspect($value)} could not be found in #{inspect($list)}.');
  }

  @else if $index == 1 {
    @return throw-warning('previous():: #{inspect($value)} is the first item in #{inspect($list)}.');
  }

  @return nth($list, $index - 1);
}