Scala example source code file (Tuple2.scala)

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Java - Scala tags/keywords

boolean, cbf, el1, el1, el2, el2, ilike, repr2, repr2, t1, t2, to, to, zipped

The Scala Tuple2.scala source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2002-2011, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */
// GENERATED CODE: DO NOT EDIT. See scala.Function0 for timestamp.

package scala

import scala.collection.{ TraversableLike => TLike, IterableLike => ILike }
import scala.collection.generic.{ CanBuildFrom => CBF }


/** A tuple of 2 elements; the canonical representation of a [[scala.Product2]].
 *
 *  @constructor  Create a new tuple with 2 elements. Note that it is more idiomatic to create a Tuple2 via `(t1, t2)`
 *  @param  _1   Element 1 of this Tuple2
 *  @param  _2   Element 2 of this Tuple2
 */
case class Tuple2[@specialized(Int, Long, Double) +T1, @specialized(Int, Long, Double) +T2](_1: T1, _2: T2)
  extends Product2[T1, T2]
{  
  override def toString() = "(" + _1 + "," + _2 + ")"  
  
  /** Swaps the elements of this `Tuple`.
   * @return a new Tuple where the first element is the second element of this Tuple and the 
   * second element is the first element of this Tuple.
   */
  def swap: Tuple2[T2,T1] = Tuple2(_2, _1)

  @deprecated("Use `zipped` instead.", "2.9.0")
  def zip[Repr1, El1, El2, To](implicit w1:   T1 => TLike[El1, Repr1],
                                        w2:   T2 => Iterable[El2],
                                        cbf1: CBF[Repr1, (El1, El2), To]): To = {
    zipped map ((x, y) => ((x, y)))
  }

  /** Wraps a tuple in a `Zipped`, which supports 2-ary generalisations of `map`, `flatMap`, `filter`, etc.
   * Note that there must be an implicit value to convert this tuple's types into a [[scala.collection.TraversableLike]]
   * or [[scala.collection.IterableLike]].
   * {{{
   * scala> val tuple = (List(1,2,3),List('a','b','c'))
   * tuple: (List[Int], List[Char]) = (List(1, 2, 3),List(a, b, c))
   *
   * scala> tuple.zipped map { (x,y) => x + ":" + y }
   * res6: List[java.lang.String] = List(1:a, 2:b, 3:c)
   * }}}
   *
   * @see Zipped
   * Note: will not terminate for infinite-sized collections.
   */
  def zipped[Repr1, El1, Repr2, El2](implicit w1: T1 => TLike[El1, Repr1], w2: T2 => ILike[El2, Repr2]): Zipped[Repr1, El1, Repr2, El2]
    = new Zipped[Repr1, El1, Repr2, El2](_1, _2)

  class Zipped[+Repr1, +El1, +Repr2, +El2](coll1: TLike[El1, Repr1], coll2: ILike[El2, Repr2]) { // coll2: ILike for filter
    def map[B, To](f: (El1, El2) => B)(implicit cbf: CBF[Repr1, B, To]): To = {
      val b = cbf(coll1.repr)
      b.sizeHint(coll1)
      val elems2 = coll2.iterator

      for (el1 <- coll1) {
        if (elems2.hasNext)
          b += f(el1, elems2.next)
        else
          return b.result
      }

      b.result
    }

    def flatMap[B, To](f: (El1, El2) => TraversableOnce[B])(implicit cbf: CBF[Repr1, B, To]): To = {
      val b = cbf(coll1.repr)
      val elems2 = coll2.iterator

      for (el1 <- coll1) {
        if (elems2.hasNext)
          b ++= f(el1, elems2.next)
        else
          return b.result
      }

      b.result
    }

    def filter[To1, To2](f: (El1, El2) => Boolean)(implicit cbf1: CBF[Repr1, El1, To1], cbf2: CBF[Repr2, El2, To2]): (To1, To2) = {
      val b1 = cbf1(coll1.repr)
      val b2 = cbf2(coll2.repr)
      val elems2 = coll2.iterator

      for (el1 <- coll1) {
        if (elems2.hasNext) {
          val el2 = elems2.next
          if (f(el1, el2)) {
            b1 += el1
            b2 += el2
          }
        }
        else return (b1.result, b2.result)
      }

      (b1.result, b2.result)
    }

    def exists(f: (El1, El2) => Boolean): Boolean = {
      val elems2 = coll2.iterator

      for (el1 <- coll1) {
        if (elems2.hasNext) {
          if (f(el1, elems2.next))
            return true
        }
        else return false
      }
      false
    }

    def forall(f: (El1, El2) => Boolean): Boolean =
      !exists((x, y) => !f(x, y))

    def foreach[U](f: (El1, El2) => U): Unit = {
      val elems2 = coll2.iterator
      
      for (el1 <- coll1) {
        if (elems2.hasNext)
          f(el1, elems2.next)
        else
          return
      }
    }
  }

}