GenTraversableLike

trait GenTraversableLike[+A, +Repr] extends GenTraversableOnce[A] with Parallelizable[A, ParIterable[A]]

A template trait for all traversable collections upon which operations may be implemented in parallel.

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Inherited
1. GenTraversableLike
2. Parallelizable
3. GenTraversableOnce
4. Any
Implicitly
1. by CollectionsHaveToParArray
3. by StringFormat
4. by Ensuring
5. by ArrowAssoc
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1. Public
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Abstract Value Members

1. abstract def /:[B](z: B)(op: (B, A) ⇒ B): B

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

Applies a binary operator to a start value and all elements of this collection or iterator, 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 or iterator, 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 or iterator.

Definition Classes
GenTraversableOnce
2. abstract def :\[B](z: B)(op: (A, B) ⇒ B): B

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

Applies a binary operator to all elements of this collection or iterator 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 or iterator, 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 or iterator.

Definition Classes
GenTraversableOnce
3. abstract 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
GenTraversableOnce
4. abstract def copyToArray[B >: A](xs: Array[B], start: Int, len: Int): Unit

Definition Classes
GenTraversableOnce
5. abstract def count(p: (A) ⇒ Boolean): Int

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

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

p

the predicate used to test elements.

returns

the number of elements satisfying the predicate `p`.

Definition Classes
GenTraversableOnce
6. abstract def drop(n: Int): Repr

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 general collection.

returns

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

7. abstract def dropWhile(pred: (A) ⇒ Boolean): Repr

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.

pred

The predicate used to test elements.

returns

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

8. abstract def exists(pred: (A) ⇒ Boolean): Boolean

Definition Classes
GenTraversableOnce
9. abstract def filter(pred: (A) ⇒ Boolean): Repr

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

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

pred

the predicate used to test elements.

returns

a new general collection consisting of all elements of this general collection that satisfy the given predicate `p`. Their order may not be preserved.

10. abstract def filterNot(pred: (A) ⇒ Boolean): Repr

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

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

pred

the predicate used to test elements.

returns

a new general collection consisting of all elements of this general collection that do not satisfy the given predicate `p`. Their order may not be preserved.

11. abstract def find(pred: (A) ⇒ Boolean): Option[A]

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

Finds the first element of the collection or iterator 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.

pred

the predicate used to test elements.

returns

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

Definition Classes
GenTraversableOnce
12. abstract def fold[A1 >: A](z: A1)(op: (A1, A1) ⇒ A1): A1

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

Folds the elements of this collection 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
GenTraversableOnce
13. abstract def foldLeft[B](z: B)(op: (B, A) ⇒ B): B

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

Applies a binary operator to a start value and all elements of this collection or iterator, 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 or iterator, 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 or iterator.

Definition Classes
GenTraversableOnce
14. abstract def foldRight[B](z: B)(op: (A, B) ⇒ B): B

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

Applies a binary operator to all elements of this collection or iterator 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 or iterator, 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 or iterator.

Definition Classes
GenTraversableOnce
15. abstract def forall(pred: (A) ⇒ Boolean): Boolean

Definition Classes
GenTraversableOnce
16. abstract def getClass(): Class[_]

Definition Classes
Any
17. abstract def groupBy[K](f: (A) ⇒ K): GenMap[K, Repr]

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

Partitions this general collection into a map of general 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 general collection.

K

the type of keys returned by the discriminator function.

f

the discriminator function.

returns

A map from keys to general 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 general collection of those elements `x` for which `f(x)` equals `k`.

18. abstract def hasDefiniteSize: Boolean

Definition Classes
GenTraversableOnce

Selects the first element of this general collection.

Selects the first element of this general collection.

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

returns

the first element of this general collection.

Exceptions thrown
`NoSuchElementException`

if the general collection is empty.

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 general collection if it is nonempty, `None` if it is empty.

21. abstract def init: Repr

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 general collection consisting of all elements of this general collection except the last one.

Exceptions thrown
`UnsupportedOperationException`

if the general collection is empty.

22. abstract def isEmpty: Boolean

Tests whether the collection or iterator is empty.

Tests whether the collection or iterator is empty.

returns

`true` if the collection or iterator contains no elements, `false` otherwise.

Definition Classes
GenTraversableOnce
23. abstract def isTraversableAgain: Boolean

Tests whether this general collection can be repeatedly traversed.

Tests whether this general collection can be repeatedly traversed.

returns

`true`

Definition Classes
GenTraversableLikeGenTraversableOnce
24. abstract 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 general collection.

Exceptions thrown
NoSuchElementException

If the general collection is empty.

25. abstract 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 general collection\$ if it is nonempty, `None` if it is empty.

26. abstract def mkString: String

Displays all elements of this collection or iterator in a string.

Displays all elements of this collection or iterator in a string.

returns

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

Definition Classes
GenTraversableOnce
27. abstract def mkString(sep: String): String

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

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

sep

the separator string.

returns

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

Definition Classes
GenTraversableOnce
Example:
1. `List(1, 2, 3).mkString("|") = "1|2|3"`

28. abstract def mkString(start: String, sep: String, end: String): String

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

Displays all elements of this collection or iterator 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 or iterator. 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 or iterator are separated by the string `sep`.

Definition Classes
GenTraversableOnce
Example:
1. `List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"`

29. abstract def nonEmpty: Boolean

Tests whether the collection or iterator is not empty.

Tests whether the collection or iterator is not empty.

returns

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

Definition Classes
GenTraversableOnce
30. abstract 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
Parallelizable
31. abstract def partition(pred: (A) ⇒ Boolean): (Repr, Repr)

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

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

pred

the predicate on which to partition.

returns

a pair of general collections: the first general collection consists of all elements that satisfy the predicate `p` and the second general collection consists of all elements that don't. The relative order of the elements in the resulting general collections may not be preserved.

32. abstract def reduce[A1 >: A](op: (A1, A1) ⇒ A1): A1

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

Reduces the elements of this collection 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 collection or iterator is nonempty.

Definition Classes
GenTraversableOnce
Exceptions thrown
UnsupportedOperationException

if this collection or iterator is empty.

33. abstract def reduceLeftOption[B >: A](op: (B, A) ⇒ B): Option[B]

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

Optionally applies a binary operator to all elements of this collection or iterator, 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 or iterator is nonempty, `None` otherwise.

Definition Classes
GenTraversableOnce
34. abstract def reduceOption[A1 >: A](op: (A1, A1) ⇒ A1): Option[A1]

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

Reduces the elements of this collection 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
GenTraversableOnce
35. abstract def reduceRight[B >: A](op: (A, B) ⇒ B): B

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

Applies a binary operator to all elements of this collection or iterator, 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 or iterator, 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 or iterator.

Definition Classes
GenTraversableOnce
Exceptions thrown
`UnsupportedOperationException`

if this collection or iterator is empty.

36. abstract def reduceRightOption[B >: A](op: (A, B) ⇒ B): Option[B]

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

Optionally applies a binary operator to all elements of this collection or iterator, 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 or iterator is nonempty, `None` otherwise.

Definition Classes
GenTraversableOnce

38. abstract def scan[B >: A, That](z: B)(op: (B, B) ⇒ B)(implicit cbf: CanBuildFrom[Repr, 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 general collection containing the prefix scan of the elements in this general collection

39. abstract def scanLeft[B, That](z: B)(op: (B, A) ⇒ B)(implicit bf: CanBuildFrom[Repr, 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

40. abstract def scanRight[B, That](z: B)(op: (A, B) ⇒ B)(implicit bf: CanBuildFrom[Repr, 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

Annotations
@migration
Migration

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

41. abstract def seq: TraversableOnce[A]

Definition Classes
Parallelizable
42. abstract def size: Int

The size of this general collection.

The size of this general collection.

Note: will not terminate for infinite-sized collections.

returns

the number of elements in this general collection.

Definition Classes
GenTraversableLikeGenTraversableOnce
43. abstract def slice(unc_from: Int, unc_until: Int): Repr

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.

unc_from

the lowest index to include from this general collection.

unc_until

the lowest index to EXCLUDE from this general collection.

returns

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

44. abstract def span(pred: (A) ⇒ Boolean): (Repr, Repr)

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

Splits this general 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.

pred

the test predicate

returns

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

45. abstract def splitAt(n: Int): (Repr, Repr)

Splits this general collection into two at a given position.

Splits this general 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 general collections consisting of the first `n` elements of this general collection, and the other elements.

46. abstract 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 general collection. By default the string prefix is the simple name of the collection class general collection.

47. abstract def tail: Repr

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 general collection consisting of all elements of this general collection except the first one.

Exceptions thrown
`UnsupportedOperationException`

if the general collection is empty.

48. abstract def take(n: Int): Repr

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 general collection.

returns

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

49. abstract def takeWhile(pred: (A) ⇒ Boolean): Repr

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.

pred

The predicate used to test elements.

returns

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

50. abstract def toBuffer[A1 >: A]: Buffer[A1]

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

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

Note: will not terminate for infinite-sized collections.

returns

a buffer containing all elements of this collection or iterator.

Definition Classes
GenTraversableOnce
51. abstract def toIndexedSeq: immutable.IndexedSeq[A]

Converts this collection or iterator to an indexed sequence.

Converts this collection or iterator to an indexed sequence.

Note: will not terminate for infinite-sized collections.

returns

an indexed sequence containing all elements of this collection or iterator.

Definition Classes
GenTraversableOnce
52. abstract def toIterable: GenIterable[A]

Converts this collection or iterator to an iterable collection.

Converts this collection or iterator 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 or iterator.

Definition Classes
GenTraversableOnce
53. abstract def toIterator: Iterator[A]

Returns an Iterator over the elements in this collection or iterator.

Returns an Iterator over the elements in this collection or iterator. 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 collection or iterator.

Definition Classes
GenTraversableOnce
54. abstract def toList: List[A]

Converts this collection or iterator to a list.

Converts this collection or iterator to a list.

Note: will not terminate for infinite-sized collections.

returns

a list containing all elements of this collection or iterator.

Definition Classes
GenTraversableOnce
55. abstract def toSeq: GenSeq[A]

Converts this collection or iterator to a sequence.

Converts this collection or iterator 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 or iterator.

Definition Classes
GenTraversableOnce
56. abstract def toSet[A1 >: A]: GenSet[A1]

Converts this collection or iterator to a set.

Converts this collection or iterator to a set.

Note: will not terminate for infinite-sized collections.

returns

a set containing all elements of this collection or iterator.

Definition Classes
GenTraversableOnce
57. abstract def toStream: Stream[A]

Converts this collection or iterator to a stream.

Converts this collection or iterator to a stream.

Note: will not terminate for infinite-sized collections.

returns

a stream containing all elements of this collection or iterator.

Definition Classes
GenTraversableOnce
58. abstract def toTraversable: GenTraversable[A]

Converts this collection or iterator to an unspecified Traversable.

Converts this collection or iterator 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 collection or iterator.

Definition Classes
GenTraversableOnce
59. abstract def toVector: Vector[A]

Converts this collection or iterator to a Vector.

Converts this collection or iterator to a Vector.

Note: will not terminate for infinite-sized collections.

returns

a vector containing all elements of this collection or iterator.

Definition Classes
GenTraversableOnce

Concrete Value Members

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

Definition Classes
Any
2. final def ##(): Int

Definition Classes
Any
3. def +(other: String): String

Implicit information
This member is added by an implicit conversion from GenTraversableLike[A, Repr] to any2stringadd[GenTraversableLike[A, Repr]] performed by method any2stringadd in scala.Predef.
Definition Classes
4. abstract def ++[B](that: GenTraversableOnce[B]): GenTraversable[B]

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

[use case]

Returns a new general collection containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the general 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 general collection which contains all elements of this general collection followed by all elements of `that`.

Full Signature

5. def ->[B](y: B): (GenTraversableLike[A, Repr], B)

Implicit information
This member is added by an implicit conversion from GenTraversableLike[A, Repr] to ArrowAssoc[GenTraversableLike[A, Repr]] performed by method ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc
Annotations
()
6. final def ==(arg0: Any): Boolean

Definition Classes
Any
7. final def asInstanceOf[T0]: T0

Definition Classes
Any
8. abstract def collect[B](pf: PartialFunction[A, B]): GenTraversable[B]

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

[use case]

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

B

the element type of the returned collection.

pf

the partial function which filters and maps the general collection.

returns

a new general 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.

Full Signature

9. abstract def copyToArray(xs: Array[A], start: Int): Unit

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

[use case]

Copies values of this general collection to an array. Fills the given array `xs` with values of this general collection, beginning at index `start`. Copying will stop once either the end of the current general 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
GenTraversableOnce
Full Signature

10. abstract def copyToArray(xs: Array[A]): Unit

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

[use case]

Copies values of this general collection to an array. Fills the given array `xs` with values of this general collection. Copying will stop once either the end of the current general 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
GenTraversableOnce
Full Signature

11. def ensuring(cond: (GenTraversableLike[A, Repr]) ⇒ Boolean, msg: ⇒ Any): GenTraversableLike[A, Repr]

Implicit information
This member is added by an implicit conversion from GenTraversableLike[A, Repr] to Ensuring[GenTraversableLike[A, Repr]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
12. def ensuring(cond: (GenTraversableLike[A, Repr]) ⇒ Boolean): GenTraversableLike[A, Repr]

Implicit information
This member is added by an implicit conversion from GenTraversableLike[A, Repr] to Ensuring[GenTraversableLike[A, Repr]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
13. def ensuring(cond: Boolean, msg: ⇒ Any): GenTraversableLike[A, Repr]

Implicit information
This member is added by an implicit conversion from GenTraversableLike[A, Repr] to Ensuring[GenTraversableLike[A, Repr]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
14. def ensuring(cond: Boolean): GenTraversableLike[A, Repr]

Implicit information
This member is added by an implicit conversion from GenTraversableLike[A, Repr] to Ensuring[GenTraversableLike[A, Repr]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
15. def equals(arg0: Any): Boolean

Definition Classes
Any
16. abstract def flatMap[B](f: (A) ⇒ GenTraversableOnce[B]): GenTraversable[B]

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

[use case]

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

Full Signature

17. abstract def foreach(f: (A) ⇒ Unit): Unit

[use case] Applies a function `f` to all elements of this general collection.

[use case]

Applies a function `f` to all elements of this general collection.

f

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

Definition Classes
GenTraversableLikeGenTraversableOnce
Full Signature

18. 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 GenTraversableLike[A, Repr] to StringFormat[GenTraversableLike[A, Repr]] performed by method StringFormat in scala.Predef.
Definition Classes
StringFormat
Annotations
()
19. def hashCode(): Int

Definition Classes
Any
20. final def isInstanceOf[T0]: Boolean

Definition Classes
Any
21. abstract def map[B](f: (A) ⇒ B): GenTraversable[B]

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

[use case]

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

B

the element type of the returned collection.

f

the function to apply to each element.

returns

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

Full Signature

22. abstract def max: A

[use case] Finds the largest element.

[use case]

Finds the largest element.

returns

the largest element of this general collection.

Definition Classes
GenTraversableOnce
Full Signature

23. abstract 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 general collection with the largest value measured by function f.

Definition Classes
GenTraversableOnce
Full Signature

24. abstract def min: A

[use case] Finds the smallest element.

[use case]

Finds the smallest element.

returns

the smallest element of this general collection

Definition Classes
GenTraversableOnce
Full Signature

25. abstract 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 general collection with the smallest value measured by function f.

Definition Classes
GenTraversableOnce
Full Signature

26. 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
27. abstract 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 general 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 general collection and as result type of `product`. Examples of such types are: `Long`, `Float`, `Double`, `BigInt`.

Definition Classes
GenTraversableOnce
Full Signature

28. abstract 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 general 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 general collection and as result type of `sum`. Examples of such types are: `Long`, `Float`, `Double`, `BigInt`.

Definition Classes
GenTraversableOnce
Full Signature

29. abstract def to[Col[_]]: Col[A]

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

[use case]

Converts this general 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 general collection.

Definition Classes
GenTraversableOnce
Full Signature

30. abstract def toArray: Array[A]

[use case] Converts this general collection to an array.

[use case]

Converts this general collection to an array.

Note: will not terminate for infinite-sized collections.

returns

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

Definition Classes
GenTraversableOnce
Full Signature

31. abstract def toMap[T, U]: Map[T, U]

[use case] Converts this general collection to a map.

[use case]

Converts this general 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 general collection.

Definition Classes
GenTraversableOnce
Full Signature

32. def toParArray: ParArray[T]

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

Definition Classes
Any
34. def →[B](y: B): (GenTraversableLike[A, Repr], B)

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