t

GenTraversableOnce 

trait GenTraversableOnce[+A] extends Any

A template trait for all traversable-once objects which may be traversed in parallel.

Methods in this trait are either abstract or can be implemented in terms of other methods.

Source
GenTraversableOnce.scala
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1. GenTraversableOnce
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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.

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.

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

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.

5. 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

6. 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.

7. 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.

8. 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.

9. 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.

10. 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.

11. 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
12. 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.

13. 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.

14. abstract def isTraversableAgain

Tests whether this collection or iterator can be repeatedly traversed.

Tests whether this collection or iterator can be repeatedly traversed. Always true for Traversables and false for Iterators unless overridden.

returns

true if it is repeatedly traversable, false otherwise.

15. 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.

16. 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.

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

17. 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.

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

18. 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.

19. 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.

Exceptions thrown

UnsupportedOperationException if this collection or iterator is empty.

20. 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.

21. 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.

22. 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.

Exceptions thrown

UnsupportedOperationException if this collection or iterator is empty.

23. 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.

24. abstract def seq: TraversableOnce[A]
25. abstract def size: Int

The size of this collection or iterator.

The size of this collection or iterator.

Note: will not terminate for infinite-sized collections.

returns

the number of elements in this collection or iterator.

26. 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.

27. 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.

28. 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.

29. 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.

30. 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.

31. 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.

32. 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.

33. 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.

34. 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.

35. 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.

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 GenTraversableOnce[A] to any2stringadd[GenTraversableOnce[A]] performed by method any2stringadd in scala.Predef.
Definition Classes
4. def ->[B](y: B): (GenTraversableOnce[A], B)
Implicit
This member is added by an implicit conversion from GenTraversableOnce[A] to ArrowAssoc[GenTraversableOnce[A]] performed by method ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc
Annotations
()
5. 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
6. 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.

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

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

[use case]

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

Full Signature

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

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

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

[use case]

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

Full Signature

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

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

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

[use case]

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

Note: will not terminate for infinite-sized collections.

xs

the array to fill.

Full Signature

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

10. def ensuring(cond: (GenTraversableOnce[A]) ⇒ Boolean, msg: ⇒ Any)
Implicit
This member is added by an implicit conversion from GenTraversableOnce[A] to Ensuring[GenTraversableOnce[A]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
11. def ensuring(cond: (GenTraversableOnce[A]) ⇒ Boolean)
Implicit
This member is added by an implicit conversion from GenTraversableOnce[A] to Ensuring[GenTraversableOnce[A]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
12. def ensuring(cond: Boolean, msg: ⇒ Any)
Implicit
This member is added by an implicit conversion from GenTraversableOnce[A] to Ensuring[GenTraversableOnce[A]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
13. def ensuring(cond: Boolean)
Implicit
This member is added by an implicit conversion from GenTraversableOnce[A] to Ensuring[GenTraversableOnce[A]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
14. 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
15. abstract def foreach(f: (A) ⇒ Unit): Unit

[use case] Applies a function f to all elements of this collection or iterator.

[use case]

Applies a function f to all elements of this collection or iterator.

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.

Full Signature

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

16. 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 GenTraversableOnce[A] to StringFormat[GenTraversableOnce[A]] performed by method StringFormat in scala.Predef.
Definition Classes
StringFormat
Annotations
()
17. 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
18. 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
19. abstract def max: A

[use case] Finds the largest element.

[use case]

Finds the largest element.

returns

the largest element of this collection or iterator.

Full Signature

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

20. 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 collection or iterator with the largest value measured by function f.

Full Signature

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

21. abstract def min: A

[use case] Finds the smallest element.

[use case]

Finds the smallest element.

returns

the smallest element of this collection or iterator

Full Signature

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

22. 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 collection or iterator with the smallest value measured by function f.

Full Signature

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

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

Full Signature

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

24. def sizeHintIfCheap: Int

The size of this collection or iterator, if it can be cheaply computed

The size of this collection or iterator, if it can be cheaply computed

returns

the number of elements in this collection or iterator, or -1 if the size cannot be determined cheaply

Attributes
protected[scala.collection]
25. 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 collection or iterator of numbers of type Int. Instead of Int, any other type T with an implicit Numeric[T] implementation can be used as element type of the collection or iterator and as result type of sum. Examples of such types are: Long, Float, Double, BigInt.

Full Signature

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

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

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

[use case]

Converts this collection or iterator into another by copying all elements.

Note: will not terminate for infinite-sized collections.

Col

The collection type to build.

returns

a new collection containing all elements of this collection or iterator.

Full Signature

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

27. abstract def toArray: Array[A]

[use case] Converts this collection or iterator to an array.

[use case]

Converts this collection or iterator to an array.

Note: will not terminate for infinite-sized collections.

returns

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

Full Signature

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

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

[use case] Converts this collection or iterator to a map.

[use case]

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

Note: will not terminate for infinite-sized collections.

returns

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

Full Signature

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

29. 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
30. def [B](y: B): (GenTraversableOnce[A], B)
Implicit
This member is added by an implicit conversion from GenTraversableOnce[A] to ArrowAssoc[GenTraversableOnce[A]] performed by method ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc