PHP 8.5 adds pipe operator(thephp.foundation)

  sum 1 2
  |> multiply 3

  let multiply b c = b \* c

  sum 1 2 |> (fun x -> multiply 3 x)

  let (|>) x f = f x

  let (>>) f g x = g (f x)
  let (<<) f g x = f (g x)

  let add1 x = x + 1
  let multiply2 x = x \* 2
  let composed = add1 >> multiply2 

    $result = $arr
        |> fn($x) => array_column($x, 'values')
        |> fn($x) => array_merge(...$x)
        |> fn($x) => array_reduce($x, fn($carry, $item) => $carry + $item, 0)
        |> fn($x) => str_repeat('x', $x);

    $values = array_merge(...array_column($arr, 'values'));
    $total  = array_reduce($values, fn($carry, $item) => $carry + $item, 0);

    $result = str_repeat('x', $x);

  $arr = [
    new Widget(tags: ['a', 'b', 'c']),
    new Widget(tags: ['c', 'd', 'e']),
    new Widget(tags: ['x', 'y', 'a']),
  ];
  
  $result = $arr
      |> fn($x) => array_column($x, 'tags') // Gets an array of arrays
      |> fn($x) => array_merge(...$x)       // Flatten into one big array
      |> array_unique(...)                  // Remove duplicates
      |> array_values(...)                  // Reindex the array.
  ;

  $result = $arr->column('tags')->flatten()->unique()->values()

  $result = $arr
    |> fn($x) => array_column($x, 'tags')
    |> fn($x) => array_merge(...$x)
    |> array_unique(...)
    |> array_values(...)

    $arr
        |> fn($x) => array_column($x, 'tags')

    $arr
        |> array_column(..., 'tags')

    $arr
        |> array_unique

  # pipeline functional style
  (1..5)
    ==> map { $_ * 2 }
    ==> grep { $_ > 5 }
    ==> say();              # (6 8 10)

  # method chain OO style
  (1..5)
    .map( * * 2)
    .grep( * > 5)
    .say;                   # (6 8 10)

  s.encode(3).count.println

        $result = $arr
            |> fn($x) => array_column($x, 'tags') // Gets an array of arrays
            |> fn($x) => array_merge(...$x)       // Flatten into one big array
            |> array_unique(...)                  // Remove duplicates
            |> array_values(...)                  // Reindex the array.
        ; // <- wtf

    result = arr.uniq.flatten.map(&:tags)

    |> fn($x) => array_column($x, 'tags')

    |> array_column(..., 'tags')

  $_ = fn_a($in)
  $_ = fb_b($_)
  $out = fn_c($_)