scala.collection.Traversable

object Traversable extends GenTraversableFactory[Traversable] with TraversableFactory[Traversable]

This object provides a set of operations to create Traversable values. The current default implementation of a Traversable is a List .

Type Members

type Coll = Traversable[_]

The underlying collection type with unknown element type

  • Attributes
    • protected[this]
  • Definition Classes
    • GenericCompanion

class GenericCanBuildFrom[A] extends CanBuildFrom[CC[_], A, CC[A]]

A generic implementation of the CanBuildFrom trait, which forwards all calls to apply(from) to the genericBuilder method of collection from , and which forwards all calls of apply() to the newBuilder method of this factory.

  • Definition Classes
    • GenTraversableFactory

Value Members From scala.collection.Traversable

implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, Traversable[A]]

The standard CanBuildFrom instance for Traversable objects. The created value is an instance of class GenericCanBuildFrom , which forwards calls to create a new builder to the genericBuilder method of the requesting collection.

(defined at scala.collection.Traversable)

def newBuilder[A]: Builder[A, Traversable[A]]

The default builder for Traversable objects.

  • A
    • the type of the collection’s elements
  • Definition Classes
    • Traversable → GenericCompanion

(defined at scala.collection.Traversable)

Value Members From scala.collection.generic.GenTraversableFactory

def ReusableCBF: GenericCanBuildFrom[Nothing]

  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def concat[A](xss: Traversable[A]*): Traversable[A]

Concatenates all argument collections into a single collection.

  • xss
    • the collections that are to be concatenated.
  • returns
    • the concatenation of all the collections.
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def fill[A](n: Int)(elem: ⇒ A): Traversable[A]

Produces a collection containing the results of some element computation a number of times.

  • n
    • the number of elements contained in the collection.
  • elem
    • the element computation
  • returns
    • A collection that contains the results of n evaluations of elem .
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def fill[A](n1: Int, n2: Int)(elem: ⇒ A): Traversable[Traversable[A]]

Produces a two-dimensional collection containing the results of some element computation a number of times.

  • n1
    • the number of elements in the 1st dimension
  • n2
    • the number of elements in the 2nd dimension
  • elem
    • the element computation
  • returns
    • A collection that contains the results of n1 x n2 evaluations of elem .
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def fill[A](n1: Int, n2: Int, n3: Int)(elem: ⇒ A): Traversable[Traversable[Traversable[A]]]

Produces a three-dimensional collection containing the results of some element computation a number of times.

  • n1
    • the number of elements in the 1st dimension
  • n2
    • the number of elements in the 2nd dimension
  • n3
    • the number of elements in the 3nd dimension
  • elem
    • the element computation
  • returns
    • A collection that contains the results of n1 x n2 x n3 evaluations of elem .
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def fill[A](n1: Int, n2: Int, n3: Int, n4: Int)(elem: ⇒ A): Traversable[Traversable[Traversable[Traversable[A]]]]

Produces a four-dimensional collection containing the results of some element computation a number of times.

  • n1
    • the number of elements in the 1st dimension
  • n2
    • the number of elements in the 2nd dimension
  • n3
    • the number of elements in the 3nd dimension
  • n4
    • the number of elements in the 4th dimension
  • elem
    • the element computation
  • returns
    • A collection that contains the results of n1 x n2 x n3 x n4 evaluations of elem .
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def fill[A](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(elem: ⇒ A): Traversable[Traversable[Traversable[Traversable[Traversable[A]]]]]

Produces a five-dimensional collection containing the results of some element computation a number of times.

  • n1
    • the number of elements in the 1st dimension
  • n2
    • the number of elements in the 2nd dimension
  • n3
    • the number of elements in the 3nd dimension
  • n4
    • the number of elements in the 4th dimension
  • n5
    • the number of elements in the 5th dimension
  • elem
    • the element computation
  • returns
    • A collection that contains the results of n1 x n2 x n3 x n4 x n5 evaluations of elem .
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def iterate[A](start: A, len: Int)(f: (A) ⇒ A): Traversable[A]

Produces a collection containing repeated applications of a function to a start value.

  • start
    • the start value of the collection
  • len
    • the number of elements contained inthe collection
  • f
    • the function that’s repeatedly applied
  • returns
    • a collection with len values in the sequence start, f(start), f(f(start)), ...
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def range[T](start: T, end: T)(implicit arg0: Integral[T]): Traversable[T]

Produces a collection containing a sequence of increasing of integers.

  • start
    • the first element of the collection
  • end
    • the end value of the collection (the first value NOT contained)
  • returns
    • a collection with values start, start + 1, ..., end - 1
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def range[T](start: T, end: T, step: T)(implicit arg0: Integral[T]): Traversable[T]

Produces a collection containing equally spaced values in some integer interval.

  • start
    • the start value of the collection
  • end
    • the end value of the collection (the first value NOT contained)
  • step
    • the difference between successive elements of the collection (must be positive or negative)
  • returns
    • a collection with values start, start + step, ... up to, but excluding end
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def tabulate[A](n: Int)(f: (Int) ⇒ A): Traversable[A]

Produces a collection containing values of a given function over a range of integer values starting from 0.

  • n
    • The number of elements in the collection
  • f
    • The function computing element values
  • returns
    • A collection consisting of elements f(0), ..., f(n -1)
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def tabulate[A](n1: Int, n2: Int)(f: (Int, Int) ⇒ A): Traversable[Traversable[A]]

Produces a two-dimensional collection containing values of a given function over ranges of integer values starting from 0.

  • n1
    • the number of elements in the 1st dimension
  • n2
    • the number of elements in the 2nd dimension
  • f
    • The function computing element values
  • returns
    • A collection consisting of elements f(i1, i2) for 0 <= i1 < n1 and 0 <= i2 < n2 .
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def tabulate[A](n1: Int, n2: Int, n3: Int)(f: (Int, Int, Int) ⇒ A): Traversable[Traversable[Traversable[A]]]

Produces a three-dimensional collection containing values of a given function over ranges of integer values starting from 0.

  • n1
    • the number of elements in the 1st dimension
  • n2
    • the number of elements in the 2nd dimension
  • n3
    • the number of elements in the 3nd dimension
  • f
    • The function computing element values
  • returns
    • A collection consisting of elements f(i1, i2, i3) for 0 <= i1 < n1 , 0 <= i2 < n2 , and 0 <= i3 < n3 .
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def tabulate[A](n1: Int, n2: Int, n3: Int, n4: Int)(f: (Int, Int, Int, Int) ⇒ A): Traversable[Traversable[Traversable[Traversable[A]]]]

Produces a four-dimensional collection containing values of a given function over ranges of integer values starting from 0.

  • n1
    • the number of elements in the 1st dimension
  • n2
    • the number of elements in the 2nd dimension
  • n3
    • the number of elements in the 3nd dimension
  • n4
    • the number of elements in the 4th dimension
  • f
    • The function computing element values
  • returns
    • A collection consisting of elements f(i1, i2, i3, i4) for 0 <= i1 < n1 , 0 <= i2 < n2 , 0 <= i3 < n3 , and 0 <= i4 < n4 .
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

def tabulate[A](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(f: (Int, Int, Int, Int, Int) ⇒ A): Traversable[Traversable[Traversable[Traversable[Traversable[A]]]]]

Produces a five-dimensional collection containing values of a given function over ranges of integer values starting from 0.

  • n1
    • the number of elements in the 1st dimension
  • n2
    • the number of elements in the 2nd dimension
  • n3
    • the number of elements in the 3nd dimension
  • n4
    • the number of elements in the 4th dimension
  • n5
    • the number of elements in the 5th dimension
  • f
    • The function computing element values
  • returns
    • A collection consisting of elements f(i1, i2, i3, i4, i5) for 0 <= i1 < n1 , 0 <= i2 < n2 , 0 <= i3 < n3 , 0 <= i4 < n4 , and 0 <= i5 < n5 .
  • Definition Classes
    • GenTraversableFactory

(defined at scala.collection.generic.GenTraversableFactory)

Value Members From scala.collection.generic.GenericCompanion

def apply[A](elems: A*): Traversable[A]

Creates a collection with the specified elements.

  • A
    • the type of the collection’s elements
  • elems
    • the elements of the created collection
  • returns
    • a new collection with elements elems
  • Definition Classes
    • GenericCompanion

(defined at scala.collection.generic.GenericCompanion)

def empty[A]: Traversable[A]

An empty collection of type CC[A]

  • A
    • the type of the collection’s elements
  • Definition Classes
    • GenericCompanion (defined at scala.collection.generic.GenericCompanion)

Full Source:

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

package scala
package collection

import generic._
import mutable.Builder
import scala.util.control.Breaks

/** A trait for traversable collections.
 *  All operations are guaranteed to be performed in a single-threaded manner.
 *
 *  $traversableInfo
 */
trait Traversable[+A] extends TraversableLike[A, Traversable[A]]
                         with GenTraversable[A]
                         with TraversableOnce[A]
                         with GenericTraversableTemplate[A, Traversable] {
  override def companion: GenericCompanion[Traversable] = Traversable

  override def seq: Traversable[A] = this

  /* The following methods are inherited from TraversableLike
   *
  override def isEmpty: Boolean
  override def size: Int
  override def hasDefiniteSize
  override def ++[B >: A, That](xs: GenTraversableOnce[B])(implicit bf: CanBuildFrom[Traversable[A], B, That]): That
  override def map[B, That](f: A => B)(implicit bf: CanBuildFrom[Traversable[A], B, That]): That
  override def flatMap[B, That](f: A => GenTraversableOnce[B])(implicit bf: CanBuildFrom[Traversable[A], B, That]): That
  override def filter(p: A => Boolean): Traversable[A]
  override def remove(p: A => Boolean): Traversable[A]
  override def partition(p: A => Boolean): (Traversable[A], Traversable[A])
  override def groupBy[K](f: A => K): Map[K, Traversable[A]]
  override def foreach[U](f: A => U): Unit
  override def forall(p: A => Boolean): Boolean
  override def exists(p: A => Boolean): Boolean
  override def count(p: A => Boolean): Int
  override def find(p: A => Boolean): Option[A]
  override def foldLeft[B](z: B)(op: (B, A) => B): B
  override def /: [B](z: B)(op: (B, A) => B): B
  override def foldRight[B](z: B)(op: (A, B) => B): B
  override def :\ [B](z: B)(op: (A, B) => B): B
  override def reduceLeft[B >: A](op: (B, A) => B): B
  override def reduceLeftOption[B >: A](op: (B, A) => B): Option[B]
  override def reduceRight[B >: A](op: (A, B) => B): B
  override def reduceRightOption[B >: A](op: (A, B) => B): Option[B]
  override def head: A
  override def headOption: Option[A]
  override def tail: Traversable[A]
  override def last: A
  override def lastOption: Option[A]
  override def init: Traversable[A]
  override def take(n: Int): Traversable[A]
  override def drop(n: Int): Traversable[A]
  override def slice(from: Int, until: Int): Traversable[A]
  override def takeWhile(p: A => Boolean): Traversable[A]
  override def dropWhile(p: A => Boolean): Traversable[A]
  override def span(p: A => Boolean): (Traversable[A], Traversable[A])
  override def splitAt(n: Int): (Traversable[A], Traversable[A])
  override def copyToBuffer[B >: A](dest: Buffer[B])
  override def copyToArray[B >: A](xs: Array[B], start: Int, len: Int)
  override def copyToArray[B >: A](xs: Array[B], start: Int)
  override def toArray[B >: A : ClassTag]: Array[B]
  override def toList: List[A]
  override def toIterable: Iterable[A]
  override def toSeq: Seq[A]
  override def toStream: Stream[A]
  override def sortWith(lt : (A,A) => Boolean): Traversable[A]
  override def mkString(start: String, sep: String, end: String): String
  override def mkString(sep: String): String
  override def mkString: String
  override def addString(b: StringBuilder, start: String, sep: String, end: String): StringBuilder
  override def addString(b: StringBuilder, sep: String): StringBuilder
  override def addString(b: StringBuilder): StringBuilder
  override def toString
  override def stringPrefix : String
  override def view
  override def view(from: Int, until: Int): TraversableView[A, Traversable[A]]
  */
}

/** $factoryInfo
 *  The current default implementation of a $Coll is a `List`.
 */
object Traversable extends TraversableFactory[Traversable] { self =>

  /** Provides break functionality separate from client code */
  private[collection] val breaks: Breaks = new Breaks

  /** $genericCanBuildFromInfo */
  implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, Traversable[A]] = ReusableCBF.asInstanceOf[GenericCanBuildFrom[A]]

  def newBuilder[A]: Builder[A, Traversable[A]] = immutable.Traversable.newBuilder[A]
}

/** Explicit instantiation of the `Traversable` trait to reduce class file size in subclasses. */
abstract class AbstractTraversable[+A] extends Traversable[A]