scala.collection.generic

# TraversableForwarder

#### trait TraversableForwarder[+A] extends Traversable[A]

This trait implements a forwarder for traversable objects. It forwards all calls to a different traversable, except for:

- `toString`, `hashCode`, `equals`, `stringPrefix`
- `newBuilder`, `view`

All calls creating a new traversable of the same kind.

Annotations
  @deprecated
Deprecated

  (Since version 2.11.0) Forwarding is inherently unreliable since it is not automated and new methods can be forgotten.

Version

  2.8

Since

  2.8

Linear Supertypes
Traversable[A], GenTraversable[A], GenericTraversableTemplate[A, Traversable], TraversableLike[A, Traversable[A]], GenTraversableLike[A, Traversable[A]], Parallelizable[A, ParIterable[A]], TraversableOnce[A], GenTraversableOnce[A], FilterMonadic[A, Traversable[A]], HasNewBuilder[A, Traversable[A]], AnyRef, Any
Known Subclasses
IterableForwarder, ListBuffer, SeqForwarder
Type Hierarchy Learn more about scaladoc diagrams
Ordering

1. Alphabetic
2. By inheritance

Inherited

1. TraversableForwarder
2. Traversable
3. GenTraversable
4. GenericTraversableTemplate
5. TraversableLike
6. GenTraversableLike
7. Parallelizable
8. TraversableOnce
9. GenTraversableOnce
10. FilterMonadic
11. HasNewBuilder
12. AnyRef
13. Any

Implicitly

1. by CollectionsHaveToParArray
2. by MonadOps
3. by any2stringadd
4. by StringFormat
5. by Ensuring
6. by ArrowAssoc
7. by alternateImplicit

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Visibility

1. Public
2. All

### Type Members

1. #### type Self = Traversable[A]

   The type implementing this traversable

   The type implementing this traversable

   Attributes
     protected[this]
   Definition Classes
     TraversableLike

2. #### class WithFilter extends FilterMonadic[A, Repr]

   A class supporting filtered operations.

### Abstract Value Members

1. #### abstract def underlying: Traversable[A]

   The traversable object to which calls are forwarded.

   The traversable object to which calls are forwarded.

   Attributes
     protected

### Concrete Value Members

1. #### final def !=(arg0: Any): Boolean

   Definition Classes
     AnyRef → Any

2. #### final def ##(): Int

   Definition Classes
     AnyRef → Any

3. #### def +(other: String): String

   Implicit information
     This member is added by an implicit conversion from TraversableForwarder[A] to any2stringadd[TraversableForwarder[A]] performed by method any2stringadd in scala.Predef.
   Definition Classes
     any2stringadd

4. #### def ++[B](that: GenTraversableOnce[B]): CC[B]

   [use case] Returns a new collection containing the elements from the left hand operand followed by the elements from the right hand operand.

   [use case]

   Returns a new collection containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the collection is the most specific superclass encompassing the element types of the two operands.

   Example:

       scala> val a = List(1)
       a: List[Int] = List(1)

       scala> val b = List(2)
       b: List[Int] = List(2)

       scala> val c = a ++ b
       c: List[Int] = List(1, 2)

       scala> val d = List('a')
       d: List[Char] = List(a)

       scala> val e = c ++ d
       e: List[AnyVal] = List(1, 2, a)

   B

     the element type of the returned collection.

   that

     the traversable to append.

   returns

     a new collection which contains all elements of this collection followed by all elements of `that`.

   Definition Classes
     TraversableLike → GenTraversableLike
   Full Signature

   #### def ++[B >: A, That](that: GenTraversableOnce[B])(implicit bf: CanBuildFrom[Traversable[A], B, That]): That

5. #### def ++:[B >: A, That](that: Traversable[B])(implicit bf: CanBuildFrom[Traversable[A], B, That]): That

   As with `++`, returns a new collection containing the elements from the left operand followed by the elements from the right operand.

   As with `++`, returns a new collection containing the elements from the left operand followed by the elements from the right operand.

   It differs from `++` in that the right operand determines the type of the resulting collection rather than the left one. Mnemonic: the COLon is on the side of the new COLlection type.

   Example:

       scala> val x = List(1)
       x: List[Int] = List(1)

       scala> val y = LinkedList(2)
       y: scala.collection.mutable.LinkedList[Int] = LinkedList(2)

       scala> val z = x ++: y
       z: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)

   This overload exists because: for the implementation of `++:` we should reuse that of `++` because many collections override it with more efficient versions.

   Since `TraversableOnce` has no `++` method, we have to implement that directly, but `Traversable` and down can use the overload.

   B

     the element type of the returned collection.

   That

     the class of the returned collection. Where possible, `That` is the same class as the current collection class `Repr`, but this depends on the element type `B` being admissible for that class, which means that an implicit instance of type `CanBuildFrom[Repr, B, That]` is found.

   that

     the traversable to append.

   bf

     an implicit value of class `CanBuildFrom` which determines the result class `That` from the current representation type `Repr` and and the new element type `B`.

   returns

     a new collection of type `That` which contains all elements of this traversable collection followed by all elements of `that`.

   Definition Classes
     TraversableLike

6. #### def ++:[B](that: TraversableOnce[B]): CC[B]

   [use case] As with `++`, returns a new collection containing the elements from the left operand followed by the elements from the right operand.

   [use case]

   As with `++`, returns a new collection containing the elements from the left operand followed by the elements from the right operand.

   It differs from `++` in that the right operand determines the type of the resulting collection rather than the left one. Mnemonic: the COLon is on the side of the new COLlection type.

   Example:

       scala> val x = List(1)
       x: List[Int] = List(1)

       scala> val y = LinkedList(2)
       y: scala.collection.mutable.LinkedList[Int] = LinkedList(2)

       scala> val z = x ++: y
       z: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)

   B

     the element type of the returned collection.

   that

     the traversable to append.

   returns

     a new collection which contains all elements of this collection followed by all elements of `that`.

   Definition Classes
     TraversableLike
   Full Signature

   #### def ++:[B >: A, That](that: TraversableOnce[B])(implicit bf: CanBuildFrom[Traversable[A], B, That]): That

7. #### def ->[B](y: B): (TraversableForwarder[A], B)

   Implicit information
     This member is added by an implicit conversion from TraversableForwarder[A] to ArrowAssoc[TraversableForwarder[A]] performed by method ArrowAssoc in scala.Predef.
   Definition Classes
     ArrowAssoc
   Annotations
     @inline()

8. #### def /:[B](z: B)(op: (B, A) ⇒ B): B

   Applies a binary operator to a start value and all elements of this collection, going left to right.

   Applies a binary operator to a start value and all elements of this collection, going left to right.

   Note: `/:` is alternate syntax for `foldLeft`; `z /: xs` is the same as `xs foldLeft z`.

   Examples:

   Note that the folding function used to compute b is equivalent to that used to compute c.

       scala> val a = List(1,2,3,4)
       a: List[Int] = List(1, 2, 3, 4)

       scala> val b = (5 /: a)(_+_)
       b: Int = 15

       scala> val c = (5 /: a)((x,y) => x + y)
       c: Int = 15

   Note: will not terminate for infinite-sized collections.

   Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

   B

     the result type of the binary operator.

   z

     the start value.

   op

     the binary operator.

   returns

     the result of inserting `op` between consecutive elements of this collection, going left to right with the start value `z` on the left:

         op(...op(op(z, x_1), x_2), ..., x_n)

     where `x1, ..., xn` are the elements of this collection.

   Definition Classes
     TraversableForwarder → TraversableOnce → GenTraversableOnce

9. #### def :\[B](z: B)(op: (A, B) ⇒ B): B

   Applies a binary operator to all elements of this collection and a start value, going right to left.

   Applies a binary operator to all elements of this collection and a start value, going right to left.

   Note: `:\` is alternate syntax for `foldRight`; `xs :\ z` is the same as `xs foldRight z`.

   Note: will not terminate for infinite-sized collections.

   Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

   Examples:

   Note that the folding function used to compute b is equivalent to that used to compute c.

       scala> val a = List(1,2,3,4)
       a: List[Int] = List(1, 2, 3, 4)

       scala> val b = (a :\ 5)(_+_)
       b: Int = 15

       scala> val c = (a :\ 5)((x,y) => x + y)
       c: Int = 15

   B

     the result type of the binary operator.

   z

     the start value

   op

     the binary operator

   returns

     the result of inserting `op` between consecutive elements of this collection, going right to left with the start value `z` on the right:

         op(x_1, op(x_2, ... op(x_n, z)...))

     where `x1, ..., xn` are the elements of this collection.

   Definition Classes
     TraversableForwarder → TraversableOnce → GenTraversableOnce

10. #### final def ==(arg0: Any): Boolean

    Definition Classes
      AnyRef → Any

11. #### def addString(b: mutable.StringBuilder): mutable.StringBuilder

    Appends all elements of this collection to a string builder.

    Appends all elements of this collection to a string builder. The written text consists of the string representations (w.r.t. the method `toString`) of all elements of this collection without any separator string.

    Example:

        scala> val a = List(1,2,3,4)
        a: List[Int] = List(1, 2, 3, 4)

        scala> val b = new StringBuilder()
        b: StringBuilder =

        scala> val h = a.addString(b)
        h: StringBuilder = 1234

    b

      the string builder to which elements are appended.

    returns

      the string builder `b` to which elements were appended.

    Definition Classes
      TraversableForwarder → TraversableOnce

12. #### def addString(b: mutable.StringBuilder, sep: String): mutable.StringBuilder

    Appends all elements of this collection to a string builder using a separator string.

    Appends all elements of this collection to a string builder using a separator string. The written text consists of the string representations (w.r.t. the method `toString`) of all elements of this collection, separated by the string `sep`.

    Example:

        scala> val a = List(1,2,3,4)
        a: List[Int] = List(1, 2, 3, 4)

        scala> val b = new StringBuilder()
        b: StringBuilder =

        scala> a.addString(b, ", ")
        res0: StringBuilder = 1, 2, 3, 4

    b

      the string builder to which elements are appended.

    sep

      the separator string.

    returns

      the string builder `b` to which elements were appended.

    Definition Classes
      TraversableForwarder → TraversableOnce

13. #### def addString(b: mutable.StringBuilder, start: String, sep: String, end: String): mutable.StringBuilder

    Appends all elements of this collection to a string builder using start, end, and separator strings.

    Appends all elements of this collection to a string builder using start, end, and separator strings. The written text begins with the string `start` and ends with the string `end`. Inside, the string representations (w.r.t. the method `toString`) of all elements of this collection are separated by the string `sep`.

    Example:

        scala> val a = List(1,2,3,4)
        a: List[Int] = List(1, 2, 3, 4)

        scala> val b = new StringBuilder()
        b: StringBuilder =

        scala> a.addString(b , "List(" , ", " , ")")
        res5: StringBuilder = List(1, 2, 3, 4)

    b

      the string builder to which elements are appended.

    start

      the starting string.

    sep

      the separator string.

    end

      the ending string.

    returns

      the string builder `b` to which elements were appended.

    Definition Classes
      TraversableForwarder → TraversableOnce

14. #### def aggregate[B](z: ⇒ B)(seqop: (B, A) ⇒ B, combop: (B, B) ⇒ B): B

    Aggregates the results of applying an operator to subsequent elements.

    Aggregates the results of applying an operator to subsequent elements.

    This is a more general form of `fold` and `reduce`. It has similar semantics, but does not require the result to be a supertype of the element type. It traverses the elements in different partitions sequentially, using `seqop` to update the result, and then applies `combop` to results from different partitions. The implementation of this operation may operate on an arbitrary number of collection partitions, so `combop` may be invoked an arbitrary number of times.

    For example, one might want to process some elements and then produce a `Set`. In this case, `seqop` would process an element and append it to the list, while `combop` would concatenate two lists from different partitions together. The initial value `z` would be an empty set.

        pc.aggregate(Set[Int]())(_ += process(_), _ ++ _)

    Another example is calculating geometric mean from a collection of doubles (one would typically require big doubles for this).

    B

      the type of accumulated results

    z

      the initial value for the accumulated result of the partition - this will typically be the neutral element for the `seqop` operator (e.g. `Nil` for list concatenation or `0` for summation) and may be evaluated more than once

    seqop

      an operator used to accumulate results within a partition

    combop

      an associative operator used to combine results from different partitions

    Definition Classes
      TraversableOnce → GenTraversableOnce

15. #### final def asInstanceOf[T0]: T0

    Definition Classes
      Any

16. #### def clone(): AnyRef

    Attributes
      protected[java.lang]
    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

17. #### def collect[B](pf: PartialFunction[A, B]): CC[B]

    [use case] Builds a new collection by applying a partial function to all elements of this collection on which the function is defined.

    [use case]

    Builds a new collection by applying a partial function to all elements of this collection on which the function is defined.

    B

      the element type of the returned collection.

    pf

      the partial function which filters and maps the collection.

    returns

      a new collection resulting from applying the given partial function `pf` to each element on which it is defined and collecting the results. The order of the elements is preserved.

    Definition Classes
      TraversableLike → GenTraversableLike
    Full Signature

    #### def collect[B, That](pf: PartialFunction[A, B])(implicit bf: CanBuildFrom[Traversable[A], B, That]): That

18. #### def collectFirst[B](pf: PartialFunction[A, B]): Option[B]

    Finds the first element of the traversable or iterator for which the given partial function is defined, and applies the partial function to it.

    Finds the first element of the traversable or iterator for which the given partial function is defined, and applies the partial function to it.

    Note: may not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    pf

      the partial function

    returns

      an option value containing pf applied to the first value for which it is defined, or `None` if none exists.

    Definition Classes
      TraversableOnce
    Example:

    1. `Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)`

19. #### def companion: GenericCompanion[Traversable]

    The factory companion object that builds instances of class CC.

    The factory companion object that builds instances of class CC. (or its `Iterable` superclass where class CC is not a `Seq`.)

    Definition Classes
      Traversable → GenTraversable → GenericTraversableTemplate

20. #### def copyToArray(xs: Array[A]): Unit

    [use case] Copies values of this collection to an array.

    [use case]

    Copies values of this collection to an array. Fills the given array `xs` with values of this collection. Copying will stop once either the end of the current collection is reached, or the end of the array is reached.

    Note: will not terminate for infinite-sized collections.

    xs

      the array to fill.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce
    Full Signature

    #### def copyToArray[B >: A](xs: Array[B]): Unit

21. #### def copyToArray(xs: Array[A], start: Int): Unit

    [use case] Copies values of this collection to an array.

    [use case]

    Copies values of this collection to an array. Fills the given array `xs` with values of this collection, beginning at index `start`. Copying will stop once either the end of the current collection is reached, or the end of the array is reached.

    Note: will not terminate for infinite-sized collections.

    xs

      the array to fill.

    start

      the starting index.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce
    Full Signature

    #### def copyToArray[B >: A](xs: Array[B], start: Int): Unit

22. #### def copyToArray(xs: Array[A], start: Int, len: Int): Unit

    [use case] Copies elements of this collection to an array.

    [use case]

    Copies elements of this collection to an array. Fills the given array `xs` with at most `len` elements of this collection, starting at position `start`. Copying will stop once either the end of the current collection is reached, or the end of the array is reached, or `len` elements have been copied.

    Note: will not terminate for infinite-sized collections.

    xs

      the array to fill.

    start

      the starting index.

    len

      the maximal number of elements to copy.

    Definition Classes
      TraversableForwarder → TraversableLike → TraversableOnce → GenTraversableOnce
    Full Signature

    #### def copyToArray[B >: A](xs: Array[B], start: Int, len: Int): Unit

23. #### def copyToBuffer[B >: A](dest: Buffer[B]): Unit

    Copies all elements of this collection to a buffer.

    Copies all elements of this collection to a buffer.

    Note: will not terminate for infinite-sized collections.

    dest

      The buffer to which elements are copied.

    Definition Classes
      TraversableForwarder → TraversableOnce

24. #### def count(p: (A) ⇒ Boolean): Int

    Counts the number of elements in the collection which satisfy a predicate.

    Counts the number of elements in the collection which satisfy a predicate.

    p

      the predicate used to test elements.

    returns

      the number of elements satisfying the predicate `p`.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce

25. #### def drop(n: Int): Traversable[A]

    Selects all elements except first n ones.

    Selects all elements except first n ones.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    n

      the number of elements to drop from this traversable collection.

    returns

      a traversable collection consisting of all elements of this traversable collection except the first `n` ones, or else the empty traversable collection, if this traversable collection has less than `n` elements.

    Definition Classes
      TraversableLike → GenTraversableLike

26. #### def dropWhile(p: (A) ⇒ Boolean): Traversable[A]

    Drops longest prefix of elements that satisfy a predicate.

    Drops longest prefix of elements that satisfy a predicate.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      the longest suffix of this traversable collection whose first element does not satisfy the predicate `p`.

    Definition Classes
      TraversableLike → GenTraversableLike

27. #### def ensuring(cond: (TraversableForwarder[A]) ⇒ Boolean, msg: ⇒ Any): TraversableForwarder[A]

    Implicit information
      This member is added by an implicit conversion from TraversableForwarder[A] to Ensuring[TraversableForwarder[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring

28. #### def ensuring(cond: (TraversableForwarder[A]) ⇒ Boolean): TraversableForwarder[A]

    Implicit information
      This member is added by an implicit conversion from TraversableForwarder[A] to Ensuring[TraversableForwarder[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring

29. #### def ensuring(cond: Boolean, msg: ⇒ Any): TraversableForwarder[A]

    Implicit information
      This member is added by an implicit conversion from TraversableForwarder[A] to Ensuring[TraversableForwarder[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring

30. #### def ensuring(cond: Boolean): TraversableForwarder[A]

    Implicit information
      This member is added by an implicit conversion from TraversableForwarder[A] to Ensuring[TraversableForwarder[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring

31. #### final def eq(arg0: AnyRef): Boolean

    Definition Classes
      AnyRef

32. #### def equals(arg0: Any): Boolean

    Definition Classes
      AnyRef → Any

33. #### def exists(p: (A) ⇒ Boolean): Boolean

    Tests whether a predicate holds for some of the elements of this collection.

    Tests whether a predicate holds for some of the elements of this collection.

    Note: may not terminate for infinite-sized collections.

    p

      the predicate used to test elements.

    returns

      `true` if the given predicate `p` holds for some of the elements of this collection, otherwise `false`.

    Definition Classes
      TraversableForwarder → TraversableLike → TraversableOnce → GenTraversableOnce

34. #### def filter(p: (A) ⇒ Boolean): Traversable[A]

    Selects all elements of this traversable collection which satisfy a predicate.

    Selects all elements of this traversable collection which satisfy a predicate.

    p

      the predicate used to test elements.

    returns

      a new traversable collection consisting of all elements of this traversable collection that satisfy the given predicate `p`. The order of the elements is preserved.

    Definition Classes
      TraversableLike → GenTraversableLike

35. #### def filterNot(p: (A) ⇒ Boolean): Traversable[A]

    Selects all elements of this traversable collection which do not satisfy a predicate.

    Selects all elements of this traversable collection which do not satisfy a predicate.

    p

      the predicate used to test elements.

    returns

      a new traversable collection consisting of all elements of this traversable collection that do not satisfy the given predicate `p`. The order of the elements is preserved.

    Definition Classes
      TraversableLike → GenTraversableLike

36. #### def finalize(): Unit

    Attributes
      protected[java.lang]
    Definition Classes
      AnyRef
    Annotations
      @throws( classOf[java.lang.Throwable] )

37. #### def find(p: (A) ⇒ Boolean): Option[A]

    Finds the first element of the collection satisfying a predicate, if any.

    Finds the first element of the collection satisfying a predicate, if any.

    Note: may not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    p

      the predicate used to test elements.

    returns

      an option value containing the first element in the collection that satisfies `p`, or `None` if none exists.

    Definition Classes
      TraversableForwarder → TraversableLike → TraversableOnce → GenTraversableOnce

38. #### def flatMap[B](f: (A) ⇒ GenTraversableOnce[B]): CC[B]

    [use case] Builds a new collection by applying a function to all elements of this collection and using the elements of the resulting collections.

    [use case]

    Builds a new collection by applying a function to all elements of this collection and using the elements of the resulting collections.

    For example:

        def getWords(lines: Seq[String]): Seq[String] = lines flatMap (line => line split "\\W+")

    The type of the resulting collection is guided by the static type of collection. This might cause unexpected results sometimes. For example:

        // lettersOf will return a Seq[Char] of likely repeated letters, instead of a Set
        def lettersOf(words: Seq[String]) = words flatMap (word => word.toSet)

        // lettersOf will return a Set[Char], not a Seq
        def lettersOf(words: Seq[String]) = words.toSet flatMap (word => word.toSeq)

        // xs will be an Iterable[Int]
        val xs = Map("a" -> List(11,111), "b" -> List(22,222)).flatMap(_._2)

        // ys will be a Map[Int, Int]
        val ys = Map("a" -> List(1 -> 11,1 -> 111), "b" -> List(2 -> 22,2 -> 222)).flatMap(_._2)

    B

      the element type of the returned collection.

    f

      the function to apply to each element.

    returns

      a new collection resulting from applying the given collection-valued function `f` to each element of this collection and concatenating the results.

    Definition Classes
      TraversableLike → GenTraversableLike → FilterMonadic
    Full Signature

    #### def flatMap[B, That](f: (A) ⇒ GenTraversableOnce[B])(implicit bf: CanBuildFrom[Traversable[A], B, That]): That

39. #### def flatten[B]: CC[B]

    [use case] Converts this collection of traversable collections into a collection formed by the elements of these traversable collections.

    [use case]

    Converts this collection of traversable collections into a collection formed by the elements of these traversable collections.

    The resulting collection's type will be guided by the static type of collection. For example:

        val xs = List(
                   Set(1, 2, 3),
                   Set(1, 2, 3)
                 ).flatten
        // xs == List(1, 2, 3, 1, 2, 3)

        val ys = Set(
                   List(1, 2, 3),
                   List(3, 2, 1)
                 ).flatten
        // ys == Set(1, 2, 3)

    B

      the type of the elements of each traversable collection.

    returns

      a new collection resulting from concatenating all element collections.

    Definition Classes
      GenericTraversableTemplate
    Full Signature

    #### def flatten[B](implicit asTraversable: (A) ⇒ GenTraversableOnce[B]): Traversable[B]

40. #### def fold[A1 >: A](z: A1)(op: (A1, A1) ⇒ A1): A1

    Folds the elements of this traversable or iterator using the specified associative binary operator.

    Folds the elements of this traversable or iterator using the specified associative binary operator.

    The order in which operations are performed on elements is unspecified and may be nondeterministic.

    A1

      a type parameter for the binary operator, a supertype of `A`.

    z

      a neutral element for the fold operation; may be added to the result an arbitrary number of times, and must not change the result (e.g., `Nil` for list concatenation, 0 for addition, or 1 for multiplication.)

    op

      a binary operator that must be associative

    returns

      the result of applying fold operator `op` between all the elements and `z`

    Definition Classes
      TraversableOnce → GenTraversableOnce

41. #### def foldLeft[B](z: B)(op: (B, A) ⇒ B): B

    Applies a binary operator to a start value and all elements of this collection, going left to right.

    Applies a binary operator to a start value and all elements of this collection, going left to right.

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

    B

      the result type of the binary operator.

    z

      the start value.

    op

      the binary operator.

    returns

      the result of inserting `op` between consecutive elements of this collection, going left to right with the start value `z` on the left:

          op(...op(z, x_1), x_2, ..., x_n)

      where `x1, ..., xn` are the elements of this collection.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce

42. #### def foldRight[B](z: B)(op: (A, B) ⇒ B): B

    Applies a binary operator to all elements of this collection and a start value, going right to left.

    Applies a binary operator to all elements of this collection and a start value, going right to left.

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

    B

      the result type of the binary operator.

    z

      the start value.

    op

      the binary operator.

    returns

      the result of inserting `op` between consecutive elements of this collection, going right to left with the start value `z` on the right:

          op(x_1, op(x_2, ... op(x_n, z)...))

      where `x1, ..., xn` are the elements of this collection.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce

43. #### def forall(p: (A) ⇒ Boolean): Boolean

    Tests whether a predicate holds for all elements of this collection.

    Tests whether a predicate holds for all elements of this collection.

    Note: may not terminate for infinite-sized collections.

    p

      the predicate used to test elements.

    returns

      `true` if the given predicate `p` holds for all elements of this collection, otherwise `false`.

    Definition Classes
      TraversableForwarder → TraversableLike → TraversableOnce → GenTraversableOnce

44. #### def foreach(f: (A) ⇒ Unit): Unit

    [use case]

    [use case]
    f

      the function that is applied for its side-effect to every element. The result of function `f` is discarded.

    Definition Classes
      TraversableForwarder → GenericTraversableTemplate → TraversableLike → GenTraversableLike → TraversableOnce → GenTraversableOnce → FilterMonadic
    Full Signature

    #### def foreach[B](f: (A) ⇒ B): Unit

45. #### def formatted(fmtstr: String): String

    Returns string formatted according to given `format` string.

    Returns string formatted according to given `format` string. Format strings are as for `String.format` (@see java.lang.String.format).

    Implicit information
      This member is added by an implicit conversion from TraversableForwarder[A] to StringFormat[TraversableForwarder[A]] performed by method StringFormat in scala.Predef.
    Definition Classes
      StringFormat
    Annotations
      @inline()

46. #### def genericBuilder[B]: Builder[B, Traversable[B]]

    The generic builder that builds instances of CC at arbitrary element types.

    The generic builder that builds instances of CC at arbitrary element types.

    Definition Classes
      GenericTraversableTemplate

47. #### final def getClass(): Class[_]

    Definition Classes
      AnyRef → Any

48. #### def groupBy[K](f: (A) ⇒ K): immutable.Map[K, Traversable[A]]

    Partitions this traversable collection into a map of traversable collections according to some discriminator function.

    Partitions this traversable collection into a map of traversable collections according to some discriminator function.

    Note: this method is not re-implemented by views. This means when applied to a view it will always force the view and return a new traversable collection.

    K

      the type of keys returned by the discriminator function.

    f

      the discriminator function.

    returns

      A map from keys to traversable collections such that the following invariant holds:

          (xs groupBy f)(k) = xs filter (x => f(x) == k)

      That is, every key `k` is bound to a traversable collection of those elements `x` for which `f(x)` equals `k`.

    Definition Classes
      TraversableLike → GenTraversableLike

49. #### def hasDefiniteSize: Boolean

    Tests whether this collection is known to have a finite size.

    Tests whether this collection is known to have a finite size. All strict collections are known to have finite size. For a non-strict collection such as `Stream`, the predicate returns `true` if all elements have been computed. It returns `false` if the stream is not yet evaluated to the end.

    Note: many collection methods will not work on collections of infinite sizes.

    returns

      `true` if this collection is known to have finite size, `false` otherwise.

    Definition Classes
      TraversableForwarder → TraversableLike → TraversableOnce → GenTraversableOnce

50. #### def hashCode(): Int

    Definition Classes
      AnyRef → Any

51. #### def head: A

    Selects the first element of this collection.

    Selects the first element of this collection.

    returns

      the first element of this collection.

    Definition Classes
      TraversableForwarder → GenericTraversableTemplate → TraversableLike → GenTraversableLike
    Exceptions thrown
      `NoSuchElementException`

      if the collection is empty.

52. #### def headOption: Option[A]

    Optionally selects the first element.

    Optionally selects the first element.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      the first element of this collection if it is nonempty, `None` if it is empty.

    Definition Classes
      TraversableForwarder → TraversableLike → GenTraversableLike

53. #### def init: Traversable[A]

    Selects all elements except the last.

    Selects all elements except the last.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      a traversable collection consisting of all elements of this traversable collection except the last one.

    Definition Classes
      TraversableLike → GenTraversableLike
    Exceptions thrown
      `UnsupportedOperationException`

      if the traversable collection is empty.

54. #### def inits: Iterator[Traversable[A]]

    Iterates over the inits of this traversable collection.

    Iterates over the inits of this traversable collection. The first value will be this traversable collection and the final one will be an empty traversable collection, with the intervening values the results of successive applications of `init`.

    returns

      an iterator over all the inits of this traversable collection

    Definition Classes
      TraversableLike
    Example:

    1. `List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)`

55. #### def isEmpty: Boolean

    Tests whether this collection is empty.

    Tests whether this collection is empty.

    returns

      `true` if the collection contain no elements, `false` otherwise.

    Definition Classes
      TraversableForwarder → GenericTraversableTemplate → TraversableLike → TraversableOnce → GenTraversableOnce

56. #### final def isInstanceOf[T0]: Boolean

    Definition Classes
      Any

57. #### final def isTraversableAgain: Boolean

    Tests whether this traversable collection can be repeatedly traversed.

    Tests whether this traversable collection can be repeatedly traversed.

    returns

      `true`

    Definition Classes
      TraversableLike → GenTraversableLike → GenTraversableOnce

58. #### def last: A

    Selects the last element.

    Selects the last element.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      The last element of this collection.

    Definition Classes
      TraversableForwarder → TraversableLike → GenTraversableLike
    Exceptions thrown
      NoSuchElementException

      If the collection is empty.

59. #### def lastOption: Option[A]

    Optionally selects the last element.

    Optionally selects the last element.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      the last element of this collection$ if it is nonempty, `None` if it is empty.

    Definition Classes
      TraversableForwarder → TraversableLike → GenTraversableLike

60. #### def map[B](f: (A) ⇒ B): CC[B]

    [use case] Builds a new collection by applying a function to all elements of this collection.

    [use case]

    Builds a new collection by applying a function to all elements of this collection.

    B

      the element type of the returned collection.

    f

      the function to apply to each element.

    returns

      a new collection resulting from applying the given function `f` to each element of this collection and collecting the results.

    Definition Classes
      TraversableLike → GenTraversableLike → FilterMonadic
    Full Signature

    #### def map[B, That](f: (A) ⇒ B)(implicit bf: CanBuildFrom[Traversable[A], B, That]): That

61. #### def max: A

    [use case] Finds the largest element.

    [use case]

    Finds the largest element.

    returns

      the largest element of this collection.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce
    Full Signature

    #### def max[B >: A](implicit cmp: Ordering[B]): A

62. #### def maxBy[B](f: (A) ⇒ B): A

    [use case] Finds the first element which yields the largest value measured by function f.

    [use case]

    Finds the first element which yields the largest value measured by function f.

    B

      The result type of the function f.

    f

      The measuring function.

    returns

      the first element of this collection with the largest value measured by function f.

    Definition Classes
      TraversableOnce → GenTraversableOnce
    Full Signature

    #### def maxBy[B](f: (A) ⇒ B)(implicit cmp: Ordering[B]): A

63. #### def min: A

    [use case] Finds the smallest element.

    [use case]

    Finds the smallest element.

    returns

      the smallest element of this collection

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce
    Full Signature

    #### def min[B >: A](implicit cmp: Ordering[B]): A

64. #### def minBy[B](f: (A) ⇒ B): A

    [use case] Finds the first element which yields the smallest value measured by function f.

    [use case]

    Finds the first element which yields the smallest value measured by function f.

    B

      The result type of the function f.

    f

      The measuring function.

    returns

      the first element of this collection with the smallest value measured by function f.

    Definition Classes
      TraversableOnce → GenTraversableOnce
    Full Signature

    #### def minBy[B](f: (A) ⇒ B)(implicit cmp: Ordering[B]): A

65. #### def mkString: String

    Displays all elements of this collection in a string.

    Displays all elements of this collection in a string.

    returns

      a string representation of this collection. In the resulting string the string representations (w.r.t. the method `toString`) of all elements of this collection follow each other without any separator string.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce

66. #### def mkString(sep: String): String

    Displays all elements of this collection in a string using a separator string.

    Displays all elements of this collection in a string using a separator string.

    sep

      the separator string.

    returns

      a string representation of this collection. In the resulting string the string representations (w.r.t. the method `toString`) of all elements of this collection are separated by the string `sep`.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce
    Example:

    1. `List(1, 2, 3).mkString("|") = "1|2|3"`

67. #### def mkString(start: String, sep: String, end: String): String

    Displays all elements of this collection in a string using start, end, and separator strings.

    Displays all elements of this collection in a string using start, end, and separator strings.

    start

      the starting string.

    sep

      the separator string.

    end

      the ending string.

    returns

      a string representation of this collection. The resulting string begins with the string `start` and ends with the string `end`. Inside, the string representations (w.r.t. the method `toString`) of all elements of this collection are separated by the string `sep`.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce
    Example:

    1. `List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"`

68. #### final def ne(arg0: AnyRef): Boolean

    Definition Classes
      AnyRef

69. #### def newBuilder: Builder[A, Traversable[A]]

    The builder that builds instances of type CC[A]

    The builder that builds instances of type CC[A]

    Attributes
      protected[this]
    Definition Classes
      GenericTraversableTemplate → HasNewBuilder

70. #### def nonEmpty: Boolean

    Tests whether the collection is not empty.

    Tests whether the collection is not empty.

    returns

      `true` if the collection contains at least one element, `false` otherwise.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce

71. #### final def notify(): Unit

    Definition Classes
      AnyRef

72. #### final def notifyAll(): Unit

    Definition Classes
      AnyRef

73. #### def par: ParIterable[A]

    Returns a parallel implementation of this collection.

    Returns a parallel implementation of this collection.

    For most collection types, this method creates a new parallel collection by copying all the elements. For these collection, `par` takes linear time. Mutable collections in this category do not produce a mutable parallel collection that has the same underlying dataset, so changes in one collection will not be reflected in the other one.

    Specific collections (e.g. `ParArray` or `mutable.ParHashMap`) override this default behaviour by creating a parallel collection which shares the same underlying dataset. For these collections, `par` takes constant or sublinear time.

    All parallel collections return a reference to themselves.

    returns

      a parallel implementation of this collection

    Definition Classes
      Parallelizable

74. #### def parCombiner: Combiner[A, ParIterable[A]]

    The default `par` implementation uses the combiner provided by this method to create a new parallel collection.

    The default `par` implementation uses the combiner provided by this method to create a new parallel collection.

    returns

      a combiner for the parallel collection of type `ParRepr`

    Attributes
      protected[this]
    Definition Classes
      TraversableLike → Parallelizable

75. #### def partition(p: (A) ⇒ Boolean): (Traversable[A], Traversable[A])

    Partitions this traversable collection in two traversable collections according to a predicate.

    Partitions this traversable collection in two traversable collections according to a predicate.

    p

      the predicate on which to partition.

    returns

      a pair of traversable collections: the first traversable collection consists of all elements that satisfy the predicate `p` and the second traversable collection consists of all elements that don't. The relative order of the elements in the resulting traversable collections is the same as in the original traversable collection.

    Definition Classes
      TraversableLike → GenTraversableLike

76. #### def product: A

    [use case] Multiplies up the elements of this collection.

    [use case]

    Multiplies up the elements of this collection.

    returns

      the product of all elements in this collection of numbers of type `Int`. Instead of `Int`, any other type `T` with an implicit `Numeric[T]` implementation can be used as element type of the collection and as result type of `product`. Examples of such types are: `Long`, `Float`, `Double`, `BigInt`.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce
    Full Signature

    #### def product[B >: A](implicit num: Numeric[B]): B

77. #### def reduce[A1 >: A](op: (A1, A1) ⇒ A1): A1

    Reduces the elements of this traversable or iterator using the specified associative binary operator.

    Reduces the elements of this traversable or iterator using the specified associative binary operator.

    The order in which operations are performed on elements is unspecified and may be nondeterministic.

    A1

      A type parameter for the binary operator, a supertype of `A`.

    op

      A binary operator that must be associative.

    returns

      The result of applying reduce operator `op` between all the elements if the traversable or iterator is nonempty.

    Definition Classes
      TraversableOnce → GenTraversableOnce
    Exceptions thrown
      UnsupportedOperationException

      if this traversable or iterator is empty.

78. #### def reduceLeft[B >: A](op: (B, A) ⇒ B): B

    Applies a binary operator to all elements of this collection, going left to right.

    Applies a binary operator to all elements of this collection, going left to right.

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

    B

      the result type of the binary operator.

    op

      the binary operator.

    returns

      the result of inserting `op` between consecutive elements of this collection, going left to right:

          op( op( ... op(x_1, x_2) ..., x_{n-1}), x_n)

      where `x1, ..., xn` are the elements of this collection.

    Definition Classes
      TraversableForwarder → TraversableOnce
    Exceptions thrown
      `UnsupportedOperationException`

      if this collection is empty.

79. #### def reduceLeftOption[B >: A](op: (B, A) ⇒ B): Option[B]

    Optionally applies a binary operator to all elements of this collection, going left to right.

    Optionally applies a binary operator to all elements of this collection, going left to right.

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

    B

      the result type of the binary operator.

    op

      the binary operator.

    returns

      an option value containing the result of `reduceLeft(op)` is this collection is nonempty, `None` otherwise.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce

80. #### def reduceOption[A1 >: A](op: (A1, A1) ⇒ A1): Option[A1]

    Reduces the elements of this traversable or iterator, if any, using the specified associative binary operator.

    Reduces the elements of this traversable or iterator, if any, using the specified associative binary operator.

    The order in which operations are performed on elements is unspecified and may be nondeterministic.

    A1

      A type parameter for the binary operator, a supertype of `A`.

    op

      A binary operator that must be associative.

    returns

      An option value containing result of applying reduce operator `op` between all the elements if the collection is nonempty, and `None` otherwise.

    Definition Classes
      TraversableOnce → GenTraversableOnce

81. #### def reduceRight[B >: A](op: (A, B) ⇒ B): B

    Applies a binary operator to all elements of this collection, going right to left.

    Applies a binary operator to all elements of this collection, going right to left.

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

    B

      the result type of the binary operator.

    op

      the binary operator.

    returns

      the result of inserting `op` between consecutive elements of this collection, going right to left:

          op(x_1, op(x_2, ..., op(x_{n-1}, x_n)...))

      where `x1, ..., xn` are the elements of this collection.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce
    Exceptions thrown
      `UnsupportedOperationException`

      if this collection is empty.

82. #### def reduceRightOption[B >: A](op: (A, B) ⇒ B): Option[B]

    Optionally applies a binary operator to all elements of this collection, going right to left.

    Optionally applies a binary operator to all elements of this collection, going right to left.

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

    B

      the result type of the binary operator.

    op

      the binary operator.

    returns

      an option value containing the result of `reduceRight(op)` is this collection is nonempty, `None` otherwise.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce

83. #### def repr: Traversable[A]

    The collection of type traversable collection underlying this `TraversableLike` object.

    The collection of type traversable collection underlying this `TraversableLike` object. By default this is implemented as the `TraversableLike` object itself, but this can be overridden.

    Definition Classes
      TraversableLike → GenTraversableLike

84. #### def reversed: List[A]

    Attributes
      protected[this]
    Definition Classes
      TraversableOnce

85. #### def scan[B >: A, That](z: B)(op: (B, B) ⇒ B)(implicit cbf: CanBuildFrom[Traversable[A], B, That]): That

    Computes a prefix scan of the elements of the collection.

    Computes a prefix scan of the elements of the collection.

    Note: The neutral element `z` may be applied more than once.

    B

      element type of the resulting collection

    That

      type of the resulting collection

    z

      neutral element for the operator `op`

    op

      the associative operator for the scan

    cbf

      combiner factory which provides a combiner

    returns

      a new traversable collection containing the prefix scan of the elements in this traversable collection

    Definition Classes
      TraversableLike → GenTraversableLike

86. #### def scanLeft[B, That](z: B)(op: (B, A) ⇒ B)(implicit bf: CanBuildFrom[Traversable[A], B, That]): That

    Produces a collection containing cumulative results of applying the operator going left to right.

    Produces a collection containing cumulative results of applying the operator going left to right.

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    B

      the type of the elements in the resulting collection

    That

      the actual type of the resulting collection

    z

      the initial value

    op

      the binary operator applied to the intermediate result and the element

    bf

      an implicit value of class `CanBuildFrom` which determines the result class `That` from the current representation type `Repr` and and the new element type `B`.

    returns

      collection with intermediate results

    Definition Classes
      TraversableLike → GenTraversableLike

87. #### def scanRight[B, That](z: B)(op: (A, B) ⇒ B)(implicit bf: CanBuildFrom[Traversable[A], B, That]): That

    Produces a collection containing cumulative results of applying the operator going right to left.

    Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result.

    Note: will not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    Example:

        List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)

    B

      the type of the elements in the resulting collection

    That

      the actual type of the resulting collection

    z

      the initial value

    op

      the binary operator applied to the intermediate result and the element

    bf

      an implicit value of class `CanBuildFrom` which determines the result class `That` from the current representation type `Repr` and and the new element type `B`.

    returns

      collection with intermediate results

    Definition Classes
      TraversableLike → GenTraversableLike
    Annotations
      @migration
    Migration

      (Changed in version 2.9.0) The behavior of `scanRight` has changed. The previous behavior can be reproduced with scanRight.reverse.

88. #### def seq: Traversable[A]

    A version of this collection with all of the operations implemented sequentially (i.

    A version of this collection with all of the operations implemented sequentially (i.e. in a single-threaded manner).

    This method returns a reference to this collection. In parallel collections, it is redefined to return a sequential implementation of this collection. In both cases, it has O(1) complexity.

    returns

      a sequential view of the collection.

    Definition Classes
      Traversable → GenTraversable → Parallelizable → TraversableOnce → GenTraversableOnce

89. #### def size: Int

    The size of this collection.

    The size of this collection.

    Note: will not terminate for infinite-sized collections.

    returns

      the number of elements in this collection.

    Definition Classes
      TraversableForwarder → GenTraversableLike → TraversableOnce → GenTraversableOnce

90. #### def slice(from: Int, until: Int): Traversable[A]

    Selects an interval of elements.

    Selects an interval of elements. The returned collection is made up of all elements `x` which satisfy the invariant:

        from <= indexOf(x) < until

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      a traversable collection containing the elements greater than or equal to index `from` extending up to (but not including) index `until` of this traversable collection.

    Definition Classes
      TraversableLike → GenTraversableLike

91. #### def span(p: (A) ⇒ Boolean): (Traversable[A], Traversable[A])

    Splits this traversable collection into a prefix/suffix pair according to a predicate.

    Splits this traversable collection into a prefix/suffix pair according to a predicate.

    Note: `c span p` is equivalent to (but possibly more efficient than) `(c takeWhile p, c dropWhile p)`, provided the evaluation of the predicate `p` does not cause any side-effects.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      a pair consisting of the longest prefix of this traversable collection whose elements all satisfy `p`, and the rest of this traversable collection.

    Definition Classes
      TraversableLike → GenTraversableLike

92. #### def splitAt(n: Int): (Traversable[A], Traversable[A])

    Splits this traversable collection into two at a given position.

    Splits this traversable collection into two at a given position. Note: `c splitAt n` is equivalent to (but possibly more efficient than) `(c take n, c drop n)`.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    n

      the position at which to split.

    returns

      a pair of traversable collections consisting of the first `n` elements of this traversable collection, and the other elements.

    Definition Classes
      TraversableLike → GenTraversableLike

93. #### def stringPrefix: String

    Defines the prefix of this object's `toString` representation.

    Defines the prefix of this object's `toString` representation.

    returns

      a string representation which starts the result of `toString` applied to this traversable collection. By default the string prefix is the simple name of the collection class traversable collection.

    Definition Classes
      TraversableLike → GenTraversableLike

94. #### def sum: A

    [use case] Sums up the elements of this collection.

    [use case]

    Sums up the elements of this collection.

    returns

      the sum of all elements in this collection of numbers of type `Int`. Instead of `Int`, any other type `T` with an implicit `Numeric[T]` implementation can be used as element type of the collection and as result type of `sum`. Examples of such types are: `Long`, `Float`, `Double`, `BigInt`.

    Definition Classes
      TraversableForwarder → TraversableOnce → GenTraversableOnce
    Full Signature

    #### def sum[B >: A](implicit num: Numeric[B]): B

95. #### final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
      AnyRef

96. #### def tail: Traversable[A]

    Selects all elements except the first.

    Selects all elements except the first.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      a traversable collection consisting of all elements of this traversable collection except the first one.

    Definition Classes
      TraversableLike → GenTraversableLike
    Exceptions thrown
      `UnsupportedOperationException`

      if the traversable collection is empty.

97. #### def tails: Iterator[Traversable[A]]

    Iterates over the tails of this traversable collection.

    Iterates over the tails of this traversable collection. The first value will be this traversable collection and the final one will be an empty traversable collection, with the intervening values the results of successive applications of `tail`.

    returns

      an iterator over all the tails of this traversable collection

    Definition Classes
      TraversableLike
    Example:

    1. `List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)`

98. #### def take(n: Int): Traversable[A]

    Selects first n elements.

    Selects first n elements.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    n

      the number of elements to take from this traversable collection.

    returns

      a traversable collection consisting only of the first `n` elements of this traversable collection, or else the whole traversable collection, if it has less than `n` elements.

    Definition Classes
      TraversableLike → GenTraversableLike

99. #### def takeWhile(p: (A) ⇒ Boolean): Traversable[A]

    Takes longest prefix of elements that satisfy a predicate.

    Takes longest prefix of elements that satisfy a predicate.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      the longest prefix of this traversable collection whose elements all satisfy the predicate `p`.

    Definition Classes
      TraversableLike → GenTraversableLike

100. #### def thisCollection: Traversable[A]

     The underlying collection seen as an instance of `Traversable`.

     The underlying collection seen as an instance of `Traversable`. By default this is implemented as the current collection object itself, but this can be overridden.

     Attributes
       protected[this]
     Definition Classes
       TraversableLike

101. #### def to[Col[_]]: Col[A]

     [use case] Converts this collection into another by copying all elements.

     [use case]

     Converts this collection into another by copying all elements.

     Note: will not terminate for infinite-sized collections.

     Col

       The collection type to build.

     returns

       a new collection containing all elements of this collection.

     Definition Classes
       TraversableLike → TraversableOnce → GenTraversableOnce
     Full Signature

     #### def to[Col[_]](implicit cbf: CanBuildFrom[Nothing, A, Col[A]]): Col[A]

102. #### def toArray: Array[A]

     [use case] Converts this collection to an array.

     [use case]

     Converts this collection to an array.

     Note: will not terminate for infinite-sized collections.

     returns

       an array containing all elements of this collection. An `ClassTag` must be available for the element type of this collection.

     Definition Classes
       TraversableForwarder → TraversableOnce → GenTraversableOnce
     Full Signature

     #### def toArray[B >: A](implicit arg0: ClassTag[B]): Array[B]

103. #### def toBuffer[B >: A]: Buffer[B]

     Uses the contents of this collection to create a new mutable buffer.

     Uses the contents of this collection to create a new mutable buffer.

     Note: will not terminate for infinite-sized collections.

     returns

       a buffer containing all elements of this collection.

     Definition Classes
       TraversableForwarder → TraversableOnce → GenTraversableOnce

104. #### def toCollection(repr: Traversable[A]): Traversable[A]

     A conversion from collections of type `Repr` to `Traversable` objects.

     A conversion from collections of type `Repr` to `Traversable` objects. By default this is implemented as just a cast, but this can be overridden.

     Attributes
       protected[this]
     Definition Classes
       TraversableLike

105. #### def toIndexedSeq: immutable.IndexedSeq[A]

     Converts this collection to an indexed sequence.

     Converts this collection to an indexed sequence.

     Note: will not terminate for infinite-sized collections.

     returns

       an indexed sequence containing all elements of this collection.

     Definition Classes
       TraversableForwarder → TraversableOnce → GenTraversableOnce

106. #### def toIterable: Iterable[A]

     Converts this collection to an iterable collection.

     Converts this collection to an iterable collection. Note that the choice of target `Iterable` is lazy in this default implementation as this `TraversableOnce` may be lazy and unevaluated (i.e. it may be an iterator which is only traversable once).

     Note: will not terminate for infinite-sized collections.

     returns

       an `Iterable` containing all elements of this collection.

     Definition Classes
       TraversableForwarder → TraversableOnce → GenTraversableOnce

107. #### def toIterator: Iterator[A]

     Returns an Iterator over the elements in this traversable collection.

     Returns an Iterator over the elements in this traversable collection. Will return the same Iterator if this instance is already an Iterator.

     Note: will not terminate for infinite-sized collections.

     returns

       an Iterator containing all elements of this traversable collection.

     Definition Classes
       TraversableLike → GenTraversableOnce

108. #### def toList: immutable.List[A]

     Converts this collection to a list.

     Converts this collection to a list.

     Note: will not terminate for infinite-sized collections.

     returns

       a list containing all elements of this collection.

     Definition Classes
       TraversableForwarder → TraversableOnce → GenTraversableOnce

109. #### def toMap[T, U]: Map[T, U]

     [use case] Converts this collection to a map.

     [use case]

     Converts this collection to a map. This method is unavailable unless the elements are members of Tuple2, each ((T, U)) becoming a key-value pair in the map. Duplicate keys will be overwritten by later keys: if this is an unordered collection, which key is in the resulting map is undefined.

     Note: will not terminate for infinite-sized collections.

     returns

       a map of type `immutable.Map[T, U]` containing all key/value pairs of type `(T, U)` of this collection.

     Definition Classes
       TraversableForwarder → TraversableOnce → GenTraversableOnce
     Full Signature

     #### def toMap[T, U](implicit ev: <:<[A, (T, U)]): immutable.Map[T, U]

110. #### def toParArray: ParArray[T]

     Implicit information
       This member is added by an implicit conversion from TraversableForwarder[A] to CollectionsHaveToParArray[TraversableForwarder[A], T] performed by method CollectionsHaveToParArray in scala.collection.parallel. This conversion will take place only if an implicit value of type (TraversableForwarder[A]) ⇒ GenTraversableOnce[T] is in scope.
     Definition Classes
       CollectionsHaveToParArray

111. #### def toSeq: Seq[A]

     Converts this collection to a sequence.

     Converts this collection to a sequence. As with `toIterable`, it's lazy in this default implementation, as this `TraversableOnce` may be lazy and unevaluated.

     Note: will not terminate for infinite-sized collections.

     returns

       a sequence containing all elements of this collection.

     Definition Classes
       TraversableForwarder → TraversableOnce → GenTraversableOnce

112. #### def toSet[B >: A]: immutable.Set[B]

     Converts this collection to a set.

     Converts this collection to a set.

     Note: will not terminate for infinite-sized collections.

     returns

       a set containing all elements of this collection.

     Definition Classes
       TraversableForwarder → TraversableOnce → GenTraversableOnce

113. #### def toStream: immutable.Stream[A]

     Converts this collection to a stream.

     Converts this collection to a stream.

     returns

       a stream containing all elements of this collection.

     Definition Classes
       TraversableForwarder → TraversableLike → GenTraversableOnce

114. #### def toString(): String

     Converts this traversable collection to a string.

     Converts this traversable collection to a string.

     returns

       a string representation of this collection. By default this string consists of the `stringPrefix` of this traversable collection, followed by all elements separated by commas and enclosed in parentheses.

     Definition Classes
       TraversableLike → Any

115. #### def toTraversable: Traversable[A]

     Converts this traversable collection to an unspecified Traversable.

     Converts this traversable collection to an unspecified Traversable. Will return the same collection if this instance is already Traversable.

     Note: will not terminate for infinite-sized collections.

     returns

       a Traversable containing all elements of this traversable collection.

     Definition Classes
       TraversableLike → TraversableOnce → GenTraversableOnce
     Annotations
       @deprecatedOverriding( ... , "2.11.0" )

116. #### def toVector: Vector[A]

     Converts this traversable or iterator to a Vector.

     Converts this traversable or iterator to a Vector.

     Note: will not terminate for infinite-sized collections.

     returns

       a vector containing all elements of this traversable or iterator.

     Definition Classes
       TraversableOnce → GenTraversableOnce

117. #### def transpose[B](implicit asTraversable: (A) ⇒ GenTraversableOnce[B]): Traversable[Traversable[B]]

     Transposes this collection of traversable collections into a collection of collections.

     Transposes this collection of traversable collections into a collection of collections.

     The resulting collection's type will be guided by the static type of collection. For example:

         val xs = List(
                    Set(1, 2, 3),
                    Set(4, 5, 6)).transpose
         // xs == List(
         //         List(1, 4),
         //         List(2, 5),
         //         List(3, 6))

         val ys = Vector(
                    List(1, 2, 3),
                    List(4, 5, 6)).transpose
         // ys == Vector(
         //         Vector(1, 4),
         //         Vector(2, 5),
         //         Vector(3, 6))

     B

       the type of the elements of each traversable collection.

     asTraversable

       an implicit conversion which asserts that the element type of this collection is a `Traversable`.

     returns

       a two-dimensional collection of collections which has as nth row the nth column of this collection.

     Definition Classes
       GenericTraversableTemplate
     Annotations
       @migration
     Migration

       (Changed in version 2.9.0) `transpose` throws an `IllegalArgumentException` if collections are not uniformly sized.

     Exceptions thrown
       `IllegalArgumentException`

       if all collections in this collection are not of the same size.

118. #### def unzip[A1, A2](implicit asPair: (A) ⇒ (A1, A2)): (Traversable[A1], Traversable[A2])

     Converts this collection of pairs into two collections of the first and second half of each pair.

     Converts this collection of pairs into two collections of the first and second half of each pair.

         val xs = CC(
                    (1, "one"),
                    (2, "two"),
                    (3, "three")).unzip
         // xs == (CC(1, 2, 3),
         //        CC(one, two, three))

     A1

       the type of the first half of the element pairs

     A2

       the type of the second half of the element pairs

     asPair

       an implicit conversion which asserts that the element type of this collection is a pair.

     returns

       a pair of collections, containing the first, respectively second half of each element pair of this collection.

     Definition Classes
       GenericTraversableTemplate

119. #### def unzip3[A1, A2, A3](implicit asTriple: (A) ⇒ (A1, A2, A3)): (Traversable[A1], Traversable[A2], Traversable[A3])

     Converts this collection of triples into three collections of the first, second, and third element of each triple.

     Converts this collection of triples into three collections of the first, second, and third element of each triple.

         val xs = CC(
                    (1, "one", '1'),
                    (2, "two", '2'),
                    (3, "three", '3')).unzip3
         // xs == (CC(1, 2, 3),
         //        CC(one, two, three),
         //        CC(1, 2, 3))

     A1

       the type of the first member of the element triples

     A2

       the type of the second member of the element triples

     A3

       the type of the third member of the element triples

     asTriple

       an implicit conversion which asserts that the element type of this collection is a triple.

     returns

       a triple of collections, containing the first, second, respectively third member of each element triple of this collection.

     Definition Classes
       GenericTraversableTemplate

120. #### def view(from: Int, until: Int): TraversableView[A, Traversable[A]]

     Creates a non-strict view of a slice of this traversable collection.

     Creates a non-strict view of a slice of this traversable collection.

     Note: the difference between `view` and `slice` is that `view` produces a view of the current traversable collection, whereas `slice` produces a new traversable collection.

     Note: `view(from, to)` is equivalent to `view.slice(from, to)`

     Note: might return different results for different runs, unless the underlying collection type is ordered.

     from

       the index of the first element of the view

     until

       the index of the element following the view

     returns

       a non-strict view of a slice of this traversable collection, starting at index `from` and extending up to (but not including) index `until`.

     Definition Classes
       TraversableLike

121. #### def view: TraversableView[A, Traversable[A]]

     Creates a non-strict view of this traversable collection.

     Creates a non-strict view of this traversable collection.

     returns

       a non-strict view of this traversable collection.

     Definition Classes
       TraversableLike

122. #### final def wait(): Unit

     Definition Classes
       AnyRef
     Annotations
       @throws( ... )

123. #### final def wait(arg0: Long, arg1: Int): Unit

     Definition Classes
       AnyRef
     Annotations
       @throws( ... )

124. #### final def wait(arg0: Long): Unit

     Definition Classes
       AnyRef
     Annotations
       @throws( ... )

125. #### def withFilter(p: (A) ⇒ Boolean): FilterMonadic[A, Traversable[A]]

     Creates a non-strict filter of this traversable collection.

     Creates a non-strict filter of this traversable collection.

     Note: the difference between `c filter p` and `c withFilter p` is that the former creates a new collection, whereas the latter only restricts the domain of subsequent `map`, `flatMap`, `foreach`, and `withFilter` operations.

     Note: might return different results for different runs, unless the underlying collection type is ordered.

     p

       the predicate used to test elements.

     returns

       an object of class `WithFilter`, which supports `map`, `flatMap`, `foreach`, and `withFilter` operations. All these operations apply to those elements of this traversable collection which satisfy the predicate `p`.

     Definition Classes
       TraversableLike → FilterMonadic

126. #### def →[B](y: B): (TraversableForwarder[A], B)

     Implicit information
       This member is added by an implicit conversion from TraversableForwarder[A] to ArrowAssoc[TraversableForwarder[A]] performed by method ArrowAssoc in scala.Predef.
     Definition Classes
       ArrowAssoc

### Shadowed Implicit Value Members

1. #### def filter(p: (A) ⇒ Boolean): TraversableOnce[A]

   Implicit information
     This member is added by an implicit conversion from TraversableForwarder[A] to MonadOps[A] performed by method MonadOps in scala.collection.TraversableOnce.
   Shadowing
     This implicitly inherited member is shadowed by one or more members in this class.
     To access this member you can use a type ascription:

         (traversableForwarder: MonadOps[A]).filter(p)

   Definition Classes
     MonadOps

2. #### def flatMap[B](f: (A) ⇒ GenTraversableOnce[B]): TraversableOnce[B]

   Implicit information
     This member is added by an implicit conversion from TraversableForwarder[A] to MonadOps[A] performed by method MonadOps in scala.collection.TraversableOnce.
   Shadowing
     This implicitly inherited member is shadowed by one or more members in this class.
     To access this member you can use a type ascription:

         (traversableForwarder: MonadOps[A]).flatMap(f)

   Definition Classes
     MonadOps

3. #### def map[B](f: (A) ⇒ B): TraversableOnce[B]

   Implicit information
     This member is added by an implicit conversion from TraversableForwarder[A] to MonadOps[A] performed by method MonadOps in scala.collection.TraversableOnce.
   Shadowing
     This implicitly inherited member is shadowed by one or more members in this class.
     To access this member you can use a type ascription:

         (traversableForwarder: MonadOps[A]).map(f)

   Definition Classes
     MonadOps

4. #### def withFilter(p: (A) ⇒ Boolean): Iterator[A]

   Implicit information
     This member is added by an implicit conversion from TraversableForwarder[A] to MonadOps[A] performed by method MonadOps in scala.collection.TraversableOnce.
   Shadowing
     This implicitly inherited member is shadowed by one or more members in this class.
     To access this member you can use a type ascription:

         (traversableForwarder: MonadOps[A]).withFilter(p)

   Definition Classes
     MonadOps

### Inherited from Traversable[A]

### Inherited from GenTraversable[A]

### Inherited from GenericTraversableTemplate[A, Traversable]

### Inherited from TraversableLike[A, Traversable[A]]

### Inherited from GenTraversableLike[A, Traversable[A]]

### Inherited from Parallelizable[A, ParIterable[A]]

### Inherited from TraversableOnce[A]

### Inherited from GenTraversableOnce[A]

### Inherited from FilterMonadic[A, Traversable[A]]

### Inherited from HasNewBuilder[A, Traversable[A]]

### Inherited from AnyRef

### Inherited from Any

### Inherited by implicit conversion CollectionsHaveToParArray from TraversableForwarder[A] to CollectionsHaveToParArray[TraversableForwarder[A], T]

### Inherited by implicit conversion MonadOps from TraversableForwarder[A] to MonadOps[A]

### Inherited by implicit conversion any2stringadd from TraversableForwarder[A] to any2stringadd[TraversableForwarder[A]]

### Inherited by implicit conversion StringFormat from TraversableForwarder[A] to StringFormat[TraversableForwarder[A]]

### Inherited by implicit conversion Ensuring from TraversableForwarder[A] to Ensuring[TraversableForwarder[A]]

### Inherited by implicit conversion ArrowAssoc from TraversableForwarder[A] to ArrowAssoc[TraversableForwarder[A]]

### Inherited by implicit conversion alternateImplicit from TraversableForwarder[A] to ForceImplicitAmbiguity

### Ungrouped