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# GenIterableLike 

#### trait GenIterableLike[+A, +Repr] extends GenTraversableLike[A, Repr]

A template trait for all iterable collections which may possibly have their operations implemented in parallel.

This trait contains abstract methods and methods that can be implemented directly in terms of other methods.

Source
GenIterableLike.scala
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Inherited
1. GenIterableLike
2. GenTraversableLike
3. Parallelizable
4. GenTraversableOnce
5. Any
Implicitly
1. by CollectionsHaveToParArray
3. by StringFormat
4. by Ensuring
5. by ArrowAssoc
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Visibility
1. Public
2. All

### 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 is similar to foldLeft in that it doesn't require the result to be a supertype of the element type. In addition, it allows parallel collections to be processed in chunks, and then combines the intermediate results.

aggregate splits the collection or iterator into partitions and processes each partition by sequentially applying seqop, starting with z (like foldLeft). Those intermediate results are then combined by using combop (like fold). The implementation of this operation may operate on an arbitrary number of collection partitions (even 1), so combop may be invoked an arbitrary number of times (even 0).

As an example, consider summing up the integer values of a list of chars. The initial value for the sum is 0. First, seqop transforms each input character to an Int and adds it to the sum (of the partition). Then, combop just needs to sum up the intermediate results of the partitions:

List('a', 'b', 'c').aggregate(0)({ (sum, ch) => sum + ch.toInt }, { (p1, p2) => p1 + p2 })
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 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
5. 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.

Definition Classes
GenTraversableLike
6. 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.

Definition Classes
GenTraversableLike
7. abstract def exists(p: (A) ⇒ Boolean)

Tests whether a predicate holds for at least one element of this collection or iterator.

Tests whether a predicate holds for at least one element of this collection or iterator.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

true if the given predicate p is satisfied by at least one element of this collection or iterator, otherwise false

Definition Classes
GenTraversableOnce
8. 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.

Definition Classes
GenTraversableLike
9. 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.

Definition Classes
GenTraversableLike
10. abstract def find(p: (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.

p

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
11. 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.

Note: will not terminate for infinite-sized collections.

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 the fold operator op between all the elements and z, or z if this collection or iterator is empty.

Definition Classes
GenTraversableOnce
12. 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. Returns z if this collection or iterator is empty.

Definition Classes
GenTraversableOnce
13. 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. Returns z if this collection or iterator is empty.

Definition Classes
GenTraversableOnce
14. abstract def forall(p: (A) ⇒ Boolean)

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

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

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

true if this collection or iterator is empty or the given predicate p holds for all elements of this collection or iterator, otherwise false.

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

Returns the runtime class representation of the object.

Returns the runtime class representation of the object.

returns

a class object corresponding to the runtime type of the receiver.

Definition Classes
Any
16. 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.

Definition Classes
GenTraversableLike
17. abstract def hasDefiniteSize

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

Tests whether this collection or iterator 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. Non-empty Iterators usually return false even if they were created from a collection with a known finite size.

Note: many collection methods will not work on collections of infinite sizes. The typical failure mode is an infinite loop. These methods always attempt a traversal without checking first that hasDefiniteSize returns true. However, checking hasDefiniteSize can provide an assurance that size is well-defined and non-termination is not a concern.

returns

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

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.

Definition Classes
GenTraversableLike
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.

Definition Classes
GenTraversableLike
20. 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.

Definition Classes
GenTraversableLike
Exceptions thrown

UnsupportedOperationException if the general collection is empty.

21. abstract def isEmpty

Tests whether the collection or iterator is empty.

Tests whether the collection or iterator is empty.

Note: Implementations in subclasses that are not repeatedly traversable must take care not to consume any elements when isEmpty is called.

returns

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

Definition Classes
GenTraversableOnce
22. abstract def isTraversableAgain

Tests whether this general collection can be repeatedly traversed.

Tests whether this general collection can be repeatedly traversed.

returns

true

Definition Classes
GenTraversableLikeGenTraversableOnce
23. abstract def iterator: Iterator[A]
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.

Definition Classes
GenTraversableLike
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.

Definition Classes
GenTraversableLike
26. abstract def mkString

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)

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)

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

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.

Definition Classes
GenTraversableLike
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) if 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) if this collection or iterator is nonempty, None otherwise.

Definition Classes
GenTraversableOnce
37. abstract def repr: Repr
Definition Classes
GenTraversableLike
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

Definition Classes
GenTraversableLike
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

Definition Classes
GenTraversableLike
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

Definition Classes
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.

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.

Definition Classes
GenTraversableLike
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.

Definition Classes
GenTraversableLike
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.

Definition Classes
GenTraversableLike
46. abstract def stringPrefix

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.

Definition Classes
GenTraversableLike
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.

Definition Classes
GenTraversableLike
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.

Definition Classes
GenTraversableLike
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.

Definition Classes
GenTraversableLike
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

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.

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)

Test two objects for inequality.

Test two objects for inequality.

returns

true if !(this == that), false otherwise.

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

Equivalent to x.hashCode except for boxed numeric types and null.

Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.

returns

a hash value consistent with ==

Definition Classes
Any
3. def +(other: String)
Implicit
This member is added by an implicit conversion from GenIterableLike[A, Repr] to any2stringadd[GenIterableLike[A, Repr]] performed by method any2stringadd in scala.Predef.
Definition Classes
4. abstract def ++[B](that: GenTraversableOnce[B]): GenIterable[B]

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

[use case]

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

Definition Classes
GenTraversableLike
Full Signature

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

5. def ->[B](y: B): (GenIterableLike[A, Repr], B)
Implicit
This member is added by an implicit conversion from GenIterableLike[A, Repr] to ArrowAssoc[GenIterableLike[A, Repr]] performed by method ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc
Annotations
()
6. final def ==(arg0: Any)

Test two objects for equality.

Test two objects for equality. The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

returns

true if the receiver object is equivalent to the argument; false otherwise.

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

Cast the receiver object to be of type T0.

Cast the receiver object to be of type T0.

Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.

returns

Definition Classes
Any
Exceptions thrown

ClassCastException if the receiver object is not an instance of the erasure of type T0.

8. abstract def collect[B](pf: PartialFunction[A, B]): GenIterable[B]

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

[use case]

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

returns

a new general iterable 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
GenTraversableLike
Full Signature

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

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

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

[use case]

Copies the elements of this general iterable collection to an array. Fills the given array xs with at most len elements of this general iterable collection , starting at position start. Copying will stop once either the end of the current general iterable collection is reached, or the end of the target 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
GenTraversableOnce
Full Signature

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

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

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

[use case]

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

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

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

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

[use case]

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

Note: will not terminate for infinite-sized collections.

xs

the array to fill.

Definition Classes
GenTraversableOnce
Full Signature

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

12. def ensuring(cond: (GenIterableLike[A, Repr]) ⇒ Boolean, msg: ⇒ Any): GenIterableLike[A, Repr]
Implicit
This member is added by an implicit conversion from GenIterableLike[A, Repr] to Ensuring[GenIterableLike[A, Repr]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
13. def ensuring(cond: (GenIterableLike[A, Repr]) ⇒ Boolean): GenIterableLike[A, Repr]
Implicit
This member is added by an implicit conversion from GenIterableLike[A, Repr] to Ensuring[GenIterableLike[A, Repr]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
14. def ensuring(cond: Boolean, msg: ⇒ Any): GenIterableLike[A, Repr]
Implicit
This member is added by an implicit conversion from GenIterableLike[A, Repr] to Ensuring[GenIterableLike[A, Repr]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
15. def ensuring(cond: Boolean): GenIterableLike[A, Repr]
Implicit
This member is added by an implicit conversion from GenIterableLike[A, Repr] to Ensuring[GenIterableLike[A, Repr]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
16. def equals(arg0: Any)

Compares the receiver object (this) with the argument object (that) for equivalence.

Compares the receiver object (this) with the argument object (that) for equivalence.

Any implementation of this method should be an equivalence relation:

• It is reflexive: for any instance x of type Any, x.equals(x) should return true.
• It is symmetric: for any instances x and y of type Any, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any instances x, y, and z of type Any if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.

If you override this method, you should verify that your implementation remains an equivalence relation. Additionally, when overriding this method it is usually necessary to override hashCode to ensure that objects which are "equal" (o1.equals(o2) returns true) hash to the same scala.Int. (o1.hashCode.equals(o2.hashCode)).

returns

true if the receiver object is equivalent to the argument; false otherwise.

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

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

[use case]

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

Definition Classes
GenTraversableLike
Full Signature

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

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

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

[use case]

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

Note: this method underlies the implementation of most other bulk operations. It's important to implement this method in an efficient way.

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

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

19. def formatted(fmtstr: 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
This member is added by an implicit conversion from GenIterableLike[A, Repr] to StringFormat[GenIterableLike[A, Repr]] performed by method StringFormat in scala.Predef.
Definition Classes
StringFormat
Annotations
()
20. def hashCode(): Int

Calculate a hash code value for the object.

Calculate a hash code value for the object.

The default hashing algorithm is platform dependent.

Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)) yet not be equal (o1.equals(o2) returns false). A degenerate implementation could always return 0. However, it is required that if two objects are equal (o1.equals(o2) returns true) that they have identical hash codes (o1.hashCode.equals(o2.hashCode)). Therefore, when overriding this method, be sure to verify that the behavior is consistent with the equals method.

returns

the hash code value for this object.

Definition Classes
Any
21. final def isInstanceOf[T0]

Test whether the dynamic type of the receiver object is T0.

Test whether the dynamic type of the receiver object is T0.

Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.

returns

true if the receiver object is an instance of erasure of type T0; false otherwise.

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

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

[use case]

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

B

the element type of the returned collection.

f

the function to apply to each element.

returns

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

Definition Classes
GenTraversableLike
Full Signature

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

23. abstract def max: A

[use case] Finds the largest element.

[use case]

Finds the largest element.

returns

the largest element of this general iterable collection .

Definition Classes
GenTraversableOnce
Full Signature

#### abstract def max[A1 >: A](implicit ord: Ordering[A1]): A

24. 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 iterable collection with the largest value measured by function f.

Definition Classes
GenTraversableOnce
Full Signature

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

25. abstract def min: A

[use case] Finds the smallest element.

[use case]

Finds the smallest element.

returns

the smallest element of this general iterable collection

Definition Classes
GenTraversableOnce
Full Signature

#### abstract def min[A1 >: A](implicit ord: Ordering[A1]): A

26. 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 iterable collection with the smallest value measured by function f.

Definition Classes
GenTraversableOnce
Full Signature

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

27. 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
28. 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 iterable 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 iterable collection and as result type of product. Examples of such types are: Long, Float, Double, BigInt.

Definition Classes
GenTraversableOnce
Full Signature

#### abstract def product[A1 >: A](implicit num: Numeric[A1]): A1

29. abstract def sameElements(that: GenIterable[A])

[use case] Checks if the other iterable collection contains the same elements in the same order as this general iterable collection .

[use case]

Checks if the other iterable collection contains the same elements in the same order as this general iterable collection .

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

Note: will not terminate for infinite-sized collections.

that

the collection to compare with.

returns

true, if both collections contain the same elements in the same order, false otherwise.

Full Signature

#### abstract def sameElements[A1 >: A](that: GenIterable[A1]): Boolean

30. 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 iterable 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 iterable collection and as result type of sum. Examples of such types are: Long, Float, Double, BigInt.

Definition Classes
GenTraversableOnce
Full Signature

#### abstract def sum[A1 >: A](implicit num: Numeric[A1]): A1

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

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

[use case]

Converts this general iterable 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 iterable collection .

Definition Classes
GenTraversableOnce
Full Signature

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

32. abstract def toArray: Array[A]

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

[use case]

Converts this general iterable collection to an array.

Note: will not terminate for infinite-sized collections.

returns

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

Definition Classes
GenTraversableOnce
Full Signature

#### abstract def toArray[A1 >: A](implicit arg0: ClassTag[A1]): Array[A1]

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

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

[use case]

Converts this general iterable 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 iterable collection .

Definition Classes
GenTraversableOnce
Full Signature

#### abstract def toMap[K, V](implicit ev: <:<[A, (K, V)]): GenMap[K, V]

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

Returns a string representation of the object.

Returns a string representation of the object.

The default representation is platform dependent.

returns

a string representation of the object.

Definition Classes
Any
36. abstract def zip[B](that: GenIterable[B]): GenIterable[(A, B)]

[use case] Returns a general iterable collection formed from this general iterable collection and another iterable collection by combining corresponding elements in pairs.

[use case]

Returns a general iterable collection formed from this general iterable collection and another iterable collection by combining corresponding elements in pairs. If one of the two collections is longer than the other, its remaining elements are ignored.

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

B

the type of the second half of the returned pairs

that

The iterable providing the second half of each result pair

returns

a new general iterable collection containing pairs consisting of corresponding elements of this general iterable collection and that. The length of the returned collection is the minimum of the lengths of this general iterable collection and that.

Full Signature

#### abstract def zip[A1 >: A, B, That](that: GenIterable[B])(implicit bf: CanBuildFrom[Repr, (A1, B), That]): That

37. abstract def zipAll[B](that: Iterable[B], thisElem: A, thatElem: B): GenIterable[(A, B)]

[use case] Returns a general iterable collection formed from this general iterable collection and another iterable collection by combining corresponding elements in pairs.

[use case]

Returns a general iterable collection formed from this general iterable collection and another iterable collection by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.

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

B

the type of the second half of the returned pairs

that

The iterable providing the second half of each result pair

thisElem

the element to be used to fill up the result if this general iterable collection is shorter than that.

thatElem

the element to be used to fill up the result if that is shorter than this general iterable collection .

returns

a new general iterable collection containing pairs consisting of corresponding elements of this general iterable collection and that. The length of the returned collection is the maximum of the lengths of this general iterable collection and that. If this general iterable collection is shorter than that, thisElem values are used to pad the result. If that is shorter than this general iterable collection , thatElem values are used to pad the result.

Full Signature

#### abstract def zipAll[B, A1 >: A, That](that: GenIterable[B], thisElem: A1, thatElem: B)(implicit bf: CanBuildFrom[Repr, (A1, B), That]): That

38. abstract def zipWithIndex: GenIterable[(A, Int)]

[use case] Zips this general iterable collection with its indices.

[use case]

Zips this general iterable collection with its indices.

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

returns

A new general iterable collection containing pairs consisting of all elements of this general iterable collection paired with their index. Indices start at 0.

Full Signature

#### abstract def zipWithIndex[A1 >: A, That](implicit bf: CanBuildFrom[Repr, (A1, Int), That]): That

Example:
1. List("a", "b", "c").zipWithIndex = List(("a", 0), ("b", 1), ("c", 2))

39. def [B](y: B): (GenIterableLike[A, Repr], B)
Implicit
This member is added by an implicit conversion from GenIterableLike[A, Repr] to ArrowAssoc[GenIterableLike[A, Repr]] performed by method ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc