Scala example source code file (Product.scala)

This example Scala source code file (Product.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

any, equals, int, iterator, product

The Product.scala Scala example source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2002-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

package scala

/** Base trait for all products, which in the standard library include at
 *  least [[scala.Product1]] through [[scala.Product22]] and therefore also
 *  their subclasses [[scala.Tuple1]] through [[scala.Tuple22]].  In addition,
 *  all case classes implement `Product` with synthetically generated methods.
 *
 *  @author  Burak Emir
 *  @version 1.0
 *  @since   2.3
 */
trait Product extends Any with Equals {
  /** The n^th^ element of this product, 0-based.  In other words, for a
   *  product `A(x,,1,,, ..., x,,k,,)`, returns `x,,(n+1),,` where `0 < n < k`.
   *
   *  @param    n   the index of the element to return
   *  @throws       `IndexOutOfBoundsException`
   *  @return       the element `n` elements after the first element
   */
  def productElement(n: Int): Any

  /** The size of this product.
   *  @return     for a product `A(x,,1,,, ..., x,,k,,)`, returns `k`
   */
  def productArity: Int

  /** An iterator over all the elements of this product.
   *  @return     in the default implementation, an `Iterator[Any]`
   */
  def productIterator: Iterator[Any] = new scala.collection.AbstractIterator[Any] {
    private var c: Int = 0
    private val cmax = productArity
    def hasNext = c < cmax
    def next() = { val result = productElement(c); c += 1; result }
  }

  /** A string used in the `toString` methods of derived classes.
   *  Implementations may override this method to prepend a string prefix
   *  to the result of `toString` methods.
   *
   *  @return   in the default implementation, the empty string
   */
  def productPrefix = ""
}