def cross-product [...tables] {                                                                              05/12/2026 08:21:49 PM
  let indexed = (
    $tables
    | enumerate
    | each { |t|
        let prefix = $"t($t.index)_"
        $t.item
        | rename --block { |col| $"($prefix)($col)" }
      }
  )

  $indexed
  | reduce --fold [ ] { |table, acc|
      if ($acc | is-empty) {
        $table
      } else {
        $acc
        | each { |row|
            $table | each { |other| $row | merge $other }
          }
        | flatten
      }
    }
}