scala.collection

TraversableOnce

trait TraversableOnce [+A] extends GenTraversableOnce[A]

A template trait for collections which can be traversed either once only or one or more times.

This trait exists primarily to eliminate code duplication between Iterator and Traversable, and thus implements some of the common methods that can be implemented solely in terms of foreach without access to a Builder. It also includes a number of abstract methods whose implementations are provided by Iterator, Traversable, etc. It contains implementations common to Iterators and Traversables, such as folds, conversions, and other operations which traverse some or all of the elements and return a derived value. Directly subclassing TraversableOnce is not recommended - instead, consider declaring an Iterator with a next and hasNext method, creating an Iterator with one of the methods on the Iterator object, or declaring a subclass of Traversable.

A

the element type of the collection

Self Type
TraversableOnce[A]
Source
TraversableOnce.scala
Version

2.8

Since

2.8

Linear Supertypes
Known Subclasses
::, AbsScope, Appended, Appended, Appended, Appended, Appended, Appended, ArrayBuffer, ArrayLike, ArrayOps, ArraySeq, ArrayStack, Atom, Attribute, BitSet, BitSet, BitSet, BitSet1, BitSet2, BitSetLike, BitSetN, Buffer, BufferLike, BufferProxy, BufferWrapper, BufferedIterator, BufferedLineIterator, BufferedSource, ByOne, Comment, ConcurrentMap, Cons, Content, CountedIterator, DefaultKeySet, DefaultKeySortedSet, DefaultMap, DefaultMap, DefaultMapModel, DefaultValuesIterable, Document, DoubleLinkedList, DoubleLinkedListLike, DroppedWhile, DroppedWhile, DroppedWhile, DroppedWhile, DroppedWhile, Elem, Elements, Elements, Empty, EmptyMap, EmptyMap, EmptySet, EmptySet, EmptyView, EmptyView, EmptyView, EmptyView, EntityRef, EntryIterator, Exclusive, Filtered, Filtered, Filtered, Filtered, Filtered, FlatMapped, FlatMapped, FlatMapped, FlatMapped, Forced, Forced, Forced, Forced, Group, GroupedIterator, HashMap, HashMap, HashMap1, HashSet, HashSet, HashSet1, HashTrieMap, HashTrieSet, History, ImmutableMapAdaptor, ImmutableSetAdaptor, Impl, Inclusive, Inclusive, IndexedSeq, IndexedSeq, IndexedSeq, IndexedSeqLike, IndexedSeqLike, IndexedSeqOptimized, IndexedSeqOptimized, IndexedSeqView, Indices, IntMap, Iterable, Iterable, Iterable, IterableForwarder, IterableLike, IterableProxy, IterableProxyLike, IterableSplitter, IterableView, IterableViewLike, Iterator, JCollectionWrapper, JConcurrentMapWrapper, JDictionaryWrapper, JEnumerationWrapper, JIterableWrapper, JIteratorWrapper, JListWrapper, JMapWrapper, JMapWrapperLike, JPropertiesWrapper, JSetWrapper, LineIterator, LinearSeq, LinearSeq, LinearSeq, LinearSeqLike, LinearSeqOptimized, LinkedHashMap, LinkedHashSet, LinkedList, LinkedListLike, List, ListBuffer, ListMap, ListMap, ListSet, LongMap, Map, Map, Map, Map1, Map2, Map3, Map4, MapLike, MapLike, MapLike, MapProxy, MapProxy, MapProxy, MapProxyLike, Mapped, Mapped, Mapped, Mapped, Mapped, Mapped, MatchIterator, MetaData, MultiMap, MutableList, Nil, Node, Node, Node, NodeBuffer, NodeSeq, Null, NumericRange, ObservableBuffer, ObservableMap, ObservableSet, OpenHashMap, PCData, PagedSeq, ParArrayIterator, ParFlatHashTableIterator, ParHashMapIterator, ParHashMapIterator, ParHashSetIterator, ParHashSetIterator, ParIterator, ParIterator, ParRangeIterator, ParVectorIterator, Patched, Patched, Patched, PicklerEnv, PreciseSplitter, PrefixedAttribute, Prepended, Prepended, PriorityQueue, PriorityQueueProxy, ProcInstr, ProducerConsumerIterator, Queue, Queue, QueueProxy, Range, RefBuffer, ResizableArray, Reversed, Reversed, Reversed, RevertibleHistory, Scope, Script, SelectionSet, Seq, Seq, Seq, SeqForwarder, SeqLike, SeqLike, SeqProxy, SeqProxyLike, SeqSplitter, SeqView, SeqViewLike, Set, Set, Set, Set1, Set2, Set3, Set4, SetLike, SetLike, SetProxy, SetProxy, SetProxy, SetProxyLike, SignalContextPassingIterator, SignalContextPassingIterator, Sliced, Sliced, Sliced, Sliced, Sliced, SortedMap, SortedMap, SortedMapLike, SortedSet, SortedSet, SortedSetLike, Source, SpecialNode, Splitter, Stack, Stack, StackProxy, Stream, StreamIterator, StreamView, StreamViewLike, StringBuilder, StringLike, StringOps, SynchronizedBuffer, SynchronizedMap, SynchronizedPriorityQueue, SynchronizedQueue, SynchronizedSet, SynchronizedStack, SystemProperties, Taken, Taken, TakenWhile, TakenWhile, TakenWhile, TakenWhile, TakenWhile, Text, Transformed, Transformed, Transformed, Transformed, Transformed, Traversable, Traversable, Traversable, TraversableForwarder, TraversableLike, TraversableProxy, TraversableProxyLike, TraversableView, TraversableViewLike, TreeMap, TreeSet, UnPicklerEnv, Unparsed, UnprefixedAttribute, UnrolledBuffer, ValueSet, Vector, VectorIterator, WeakHashMap, WithDefault, WithDefault, WithDefault, WrappedArray, WrappedString, XMLEventReader, Zipped, Zipped, Zipped, Zipped, Zipped, ZippedAll, ZippedAll, ZippedAll, ZippedAll, ZippedAll, columns, indices, items, ofBoolean, ofBoolean, ofByte, ofByte, ofChar, ofChar, ofDouble, ofDouble, ofFloat, ofFloat, ofInt, ofInt, ofLong, ofLong, ofRef, ofRef, ofShort, ofShort, ofUnit, ofUnit, pages, rows
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Abstract Value Members

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

    Attributes
    abstract
    Definition Classes
    TraversableOnceGenTraversableOnce
  2. def exists (p: (A) ⇒ Boolean): Boolean

    Attributes
    abstract
    Definition Classes
    TraversableOnceGenTraversableOnce
  3. def find (p: (A) ⇒ Boolean): Option[A]

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

    Finds the first element of the traversable 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 traversable or iterator that satisfies p, or None if none exists.

    Attributes
    abstract
    Definition Classes
    TraversableOnceGenTraversableOnce
  4. def forall (p: (A) ⇒ Boolean): Boolean

    Presently these are abstract because the Traversable versions use breakable/break, and I wasn't sure enough of how that's supposed to function to consolidate them with the Iterator versions.

    Presently these are abstract because the Traversable versions use breakable/break, and I wasn't sure enough of how that's supposed to function to consolidate them with the Iterator versions.

    Attributes
    abstract
    Definition Classes
    TraversableOnceGenTraversableOnce
  5. def foreach [U] (f: (A) ⇒ U): Unit

    Self-documenting abstract methods.

    Self-documenting abstract methods.

    Attributes
    abstract
    Definition Classes
    TraversableOnceGenTraversableOnce
  6. def hasDefiniteSize : Boolean

    Attributes
    abstract
    Definition Classes
    TraversableOnceGenTraversableOnce
  7. def isEmpty : Boolean

    Tests whether the traversable or iterator is empty.

    Tests whether the traversable or iterator is empty.

    returns

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

    Attributes
    abstract
    Definition Classes
    TraversableOnceGenTraversableOnce
  8. def isTraversableAgain : Boolean

    Tests whether this traversable or iterator can be repeatedly traversed.

    Tests whether this traversable 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.

    Attributes
    abstract
    Definition Classes
    GenTraversableOnce
  9. def seq : TraversableOnce[A]

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

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

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

    returns

    a sequential view of the collection.

    Attributes
    abstract
    Definition Classes
    TraversableOnceGenTraversableOnce
  10. def toIterator : Iterator[A]

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

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

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

    Converts this traversable or iterator to a stream.

    Converts this traversable or iterator to a stream.

    Note: will not terminate for infinite-sized collections.

    returns

    a stream containing all elements of this traversable or iterator.

    Attributes
    abstract
    Definition Classes
    GenTraversableOnce
  12. def toTraversable : Traversable[A]

    Converts this traversable or iterator to an unspecified Traversable.

    Converts this traversable 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 traversable or iterator.

    Attributes
    abstract
    Definition Classes
    TraversableOnceGenTraversableOnce

Concrete Value Members

  1. def != (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef
  2. def != (arg0: Any): Boolean

    Test two objects for inequality.

    Test two objects for inequality.

    returns

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

    Attributes
    final
    Definition Classes
    Any
  3. def ## (): Int

    Equivalent to x.hashCode except for boxed numeric types.

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

    returns

    a hash value consistent with ==

    Attributes
    final
    Definition Classes
    AnyRef → Any
  4. def /: [B] (z: B)(op: (B, A) ⇒ B): B

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

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

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

    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 traversable 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 x,,1,,, ..., x,,n,, are the elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  5. def /:\ [A1 >: A] (z: A1)(op: (A1, A1) ⇒ A1): A1

    A syntactic sugar for out of order folding.

    A syntactic sugar for out of order folding. See fold.

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

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

    Applies a binary operator to all elements of this traversable 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.

    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 traversable 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 x,,1,,, ..., x,,n,, are the elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  7. def == (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef
  8. def == (arg0: Any): Boolean

    Test two objects for equality.

    Test two objects for equality.

    returns

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

    Attributes
    final
    Definition Classes
    Any
  9. def addString (b: StringBuilder): StringBuilder

    Appends all elements of this traversable or iterator to a string builder.

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

    b

    the string builder to which elements are appended.

    returns

    the string builder b to which elements were appended.

  10. def addString (b: StringBuilder, sep: String): StringBuilder

    Appends all elements of this traversable or iterator to a string builder using a separator string.

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

    b

    the string builder to which elements are appended.

    sep

    the separator string.

    returns

    the string builder b to which elements were appended.

  11. def addString (b: StringBuilder, start: String, sep: String, end: String): StringBuilder

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

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

    b

    the string builder to which elements are appended.

    start

    the starting string.

    sep

    the separator string.

    end

    the ending string.

    returns

    the string builder b to which elements were appended.

  12. 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 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).

    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)

    seqop

    an operator used to accumulate results within a partition

    combop

    an associative operator used to combine results from different partitions

    Definition Classes
    TraversableOnceGenTraversableOnce
  13. 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

    the receiver object.

    Attributes
    final
    Definition Classes
    Any
  14. def clone (): AnyRef

    Create a copy of the receiver object.

    Create a copy of the receiver object.

    The default implementation of the clone method is platform dependent.

    returns

    a copy of the receiver object.

    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  15. def collectFirst [B] (pf: PartialFunction[A, B]): Option[B]

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

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

    Note: may not terminate for infinite-sized collections.

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

    pf

    the partial function

    returns

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

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

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

    [use case] Copies values of this traversable or iterator to an array.

    [use case]

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

    xs

    the array to fill.

    Attributes
    abstract
    Definition Classes
    GenTraversableOnce
  17. def copyToArray [B >: A] (xs: Array[B]): Unit

    Copies values of this traversable or iterator to an array.

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

    Note: will not terminate for infinite-sized collections.

    B

    the type of the elements of the array.

    xs

    the array to fill.

    Definition Classes
    TraversableOnceGenTraversableOnce
  18. def copyToArray (xs: Array[A], start: Int): Unit

    [use case] Copies values of this traversable or iterator to an array.

    [use case]

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

    xs

    the array to fill.

    start

    the starting index.

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

    Copies values of this traversable or iterator to an array.

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

    Note: will not terminate for infinite-sized collections.

    B

    the type of the elements of the array.

    xs

    the array to fill.

    start

    the starting index.

    Definition Classes
    TraversableOnceGenTraversableOnce
  20. def copyToBuffer [B >: A] (dest: Buffer[B]): Unit

    Copies all elements of this traversable or iterator to a buffer.

    Copies all elements of this traversable or iterator to a buffer.

    Note: will not terminate for infinite-sized collections.

    dest

    The buffer to which elements are copied.

  21. def count (p: (A) ⇒ Boolean): Int

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

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

    p

    the predicate used to test elements.

    returns

    the number of elements satisfying the predicate p.

    Definition Classes
    TraversableOnceGenTraversableOnce
  22. def eq (arg0: AnyRef): Boolean

    Tests whether the argument (arg0) is a reference to the receiver object (this).

    Tests whether the argument (arg0) is a reference to the receiver object (this).

    The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:

    • It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.
    • For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
    • null.eq(null) returns true.

    When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

    returns

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

    Attributes
    final
    Definition Classes
    AnyRef
  23. def equals (arg0: Any): Boolean

    The equality method for reference types.

    The equality method for reference types. See equals in Any.

    returns

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

    Definition Classes
    AnyRef → Any
  24. def finalize (): Unit

    Called by the garbage collector on the receiver object when there are no more references to the object.

    Called by the garbage collector on the receiver object when there are no more references to the object.

    The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.

    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  25. def fold [A1 >: A] (z: A1)(op: (A1, A1) ⇒ A1): A1

    Folds the elements of this sequence using the specified associative binary operator.

    Folds the elements of this sequence using the specified associative binary operator. The order in which the elements are reduced is unspecified and may be nondeterministic.

    Note this method has a different signature than the foldLeft and foldRight methods of the trait Traversable. The result of folding may only be a supertype of this parallel collection's type parameter T.

    z

    a neutral element for the fold operation, it may be added to the result an arbitrary number of times, not changing 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
    TraversableOnceGenTraversableOnce
  26. def foldLeft [B] (z: B)(op: (B, A) ⇒ B): B

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

    Applies a binary operator to a start value and all elements of this traversable 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 traversable or iterator, going left to right with the start value z on the left:

                op(...op(z, x,,1,,), x,,2,,, ..., x,,n,,)
    

    where x,,1,,, ..., x,,n,, are the elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  27. def foldRight [B] (z: B)(op: (A, B) ⇒ B): B

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

    Applies a binary operator to all elements of this traversable 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 traversable 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 x,,1,,, ..., x,,n,, are the elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  28. def getClass (): java.lang.Class[_ <: java.lang.Object]

    A representation that corresponds to the dynamic class of the receiver object.

    A representation that corresponds to the dynamic class of the receiver object.

    The nature of the representation is platform dependent.

    returns

    a representation that corresponds to the dynamic class of the receiver object.

    Attributes
    final
    Definition Classes
    AnyRef
  29. def hashCode (): Int

    The hashCode method for reference types.

    The hashCode method for reference types. See hashCode in Any.

    returns

    the hash code value for this object.

    Definition Classes
    AnyRef → Any
  30. def isInstanceOf [T0] : Boolean

    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.

    Attributes
    final
    Definition Classes
    Any
  31. def max : A

    [use case] Finds the largest element.

    [use case]

    Finds the largest element.

    returns

    the largest element of this traversable or iterator with respect to the ordering cmp.

    Attributes
    abstract
    Definition Classes
    GenTraversableOnce
  32. def max [B >: A] (implicit cmp: Ordering[B]): A

    Finds the largest element.

    Finds the largest element.

    B

    The type over which the ordering is defined.

    cmp

    An ordering to be used for comparing elements.

    returns

    the largest element of this traversable or iterator with respect to the ordering cmp.

    Definition Classes
    TraversableOnceGenTraversableOnce
  33. def maxBy [B] (f: (A) ⇒ B)(implicit cmp: Ordering[B]): A

    Definition Classes
    TraversableOnceGenTraversableOnce
  34. def min : A

    [use case] Finds the smallest element.

    [use case]

    Finds the smallest element.

    returns

    the smallest element of this traversable or iterator with respect to the ordering cmp.

    Attributes
    abstract
    Definition Classes
    GenTraversableOnce
  35. def min [B >: A] (implicit cmp: Ordering[B]): A

    Finds the smallest element.

    Finds the smallest element.

    B

    The type over which the ordering is defined.

    cmp

    An ordering to be used for comparing elements.

    returns

    the smallest element of this traversable or iterator with respect to the ordering cmp.

    Definition Classes
    TraversableOnceGenTraversableOnce
  36. def minBy [B] (f: (A) ⇒ B)(implicit cmp: Ordering[B]): A

    Definition Classes
    TraversableOnceGenTraversableOnce
  37. def mkString : String

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

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

    returns

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

    Definition Classes
    TraversableOnceGenTraversableOnce
  38. def mkString (sep: String): String

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

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

    sep

    the separator string.

    returns

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

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

  39. def mkString (start: String, sep: String, end: String): String

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

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

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

  40. def ne (arg0: AnyRef): Boolean

    Equivalent to !(this eq that).

    Equivalent to !(this eq that).

    returns

    true if the argument is not a reference to the receiver object; false otherwise.

    Attributes
    final
    Definition Classes
    AnyRef
  41. def nonEmpty : Boolean

    Tests whether the traversable or iterator is not empty.

    Tests whether the traversable or iterator is not empty.

    returns

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

    Definition Classes
    TraversableOnceGenTraversableOnce
  42. def notify (): Unit

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Attributes
    final
    Definition Classes
    AnyRef
  43. def notifyAll (): Unit

    Wakes up all threads that are waiting on the receiver object's monitor.

    Wakes up all threads that are waiting on the receiver object's monitor.

    Attributes
    final
    Definition Classes
    AnyRef
  44. 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 of this traversable or iterator with respect to the * operator in num.

    Attributes
    abstract
    Definition Classes
    GenTraversableOnce
  45. def product [B >: A] (implicit num: Numeric[B]): B

    Multiplies up the elements of this collection.

    Multiplies up the elements of this collection.

    B

    the result type of the * operator.

    num

    an implicit parameter defining a set of numeric operations which includes the * operator to be used in forming the product.

    returns

    the product of all elements of this traversable or iterator with respect to the * operator in num.

    Definition Classes
    TraversableOnceGenTraversableOnce
  46. def reduce [A1 >: A] (op: (A1, A1) ⇒ A1): A1

    Reduces the elements of this sequence using the specified associative binary operator.

    Reduces the elements of this sequence using the specified associative binary operator.

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

    Note this method has a different signature than the reduceLeft and reduceRight methods of the trait Traversable. The result of reducing may only be a supertype of this parallel collection's type parameter T.

    op

    A binary operator that must be associative.

    returns

    The result of applying reduce operator op between all the elements if the collection is nonempty.

    Definition Classes
    TraversableOnceGenTraversableOnce
  47. def reduceLeft [B >: A] (op: (B, A) ⇒ B): B

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

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

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

    Definition Classes
    TraversableOnceGenTraversableOnce
  49. def reduceOption [A1 >: A] (op: (A1, A1) ⇒ A1): Option[A1]

    Optionally reduces the elements of this sequence using the specified associative binary operator.

    Optionally reduces the elements of this sequence using the specified associative binary operator.

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

    Note this method has a different signature than the reduceLeftOption and reduceRightOption methods of the trait Traversable. The result of reducing may only be a supertype of this parallel collection's type parameter T.

    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
    TraversableOnceGenTraversableOnce
  50. def reduceRight [B >: A] (op: (A, B) ⇒ B): B

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

    Applies a binary operator to all elements of this traversable 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 traversable or iterator, going right to left:

                op(x,,1,,, op(x,,2,,, ..., op(x,,n-1,,, x,,n,,)...))
    

    where x,,1,,, ..., x,,n,, are the elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  51. def reduceRightOption [B >: A] (op: (A, B) ⇒ B): Option[B]

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

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

    Definition Classes
    TraversableOnceGenTraversableOnce
  52. def reversed : List[A]

    Attributes
    protected[this]
  53. def size : Int

    The size of this traversable or iterator.

    The size of this traversable or iterator.

    Note: will not terminate for infinite-sized collections.

    returns

    the number of elements in this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  54. 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 of this traversable or iterator with respect to the + operator in num.

    Attributes
    abstract
    Definition Classes
    GenTraversableOnce
  55. def sum [B >: A] (implicit num: Numeric[B]): B

    Sums up the elements of this collection.

    Sums up the elements of this collection.

    B

    the result type of the + operator.

    num

    an implicit parameter defining a set of numeric operations which includes the + operator to be used in forming the sum.

    returns

    the sum of all elements of this traversable or iterator with respect to the + operator in num.

    Definition Classes
    TraversableOnceGenTraversableOnce
  56. def synchronized [T0] (arg0: ⇒ T0): T0

    Attributes
    final
    Definition Classes
    AnyRef
  57. def toArray : Array[A]

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

    [use case]

    Converts this traversable or iterator to an array.

    Note: will not terminate for infinite-sized collections.

    returns

    an array containing all elements of this traversable or iterator.

    Attributes
    abstract
    Definition Classes
    GenTraversableOnce
  58. def toArray [B >: A] (implicit arg0: ClassManifest[B]): Array[B]

    Converts this traversable or iterator to an array.

    Converts this traversable or iterator to an array.

    Note: will not terminate for infinite-sized collections.

    B

    the type of the elements of the array. A ClassManifest for this type must be available.

    returns

    an array containing all elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  59. def toBuffer [B >: A] : Buffer[B]

    Converts this traversable or iterator to a mutable buffer.

    Converts this traversable or iterator to a mutable buffer.

    Note: will not terminate for infinite-sized collections.

    returns

    a buffer containing all elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  60. def toIndexedSeq [B >: A] : IndexedSeq[B]

    Converts this traversable or iterator to an indexed sequence.

    Converts this traversable or iterator to an indexed sequence.

    Note: will not terminate for infinite-sized collections.

    returns

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

    Definition Classes
    TraversableOnceGenTraversableOnce
  61. def toIterable : Iterable[A]

    Converts this traversable or iterator to an iterable collection.

    Converts this traversable 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 traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  62. def toList : List[A]

    Converts this traversable or iterator to a list.

    Converts this traversable or iterator to a list.

    Note: will not terminate for infinite-sized collections.

    returns

    a list containing all elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  63. def toMap [T, U] : Map[T, U]

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

    [use case]

    Converts this traversable 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 containing all elements of this traversable or iterator.

    Attributes
    abstract
    Definition Classes
    GenTraversableOnce
  64. def toMap [T, U] (implicit ev: <:<[A, (T, U)]): Map[T, U]

    Converts this traversable or iterator to a map.

    Converts this traversable 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 containing all elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  65. def toSeq : Seq[A]

    Converts this traversable or iterator to a sequence.

    Converts this traversable 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 traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  66. def toSet [B >: A] : Set[B]

    Converts this traversable or iterator to a set.

    Converts this traversable or iterator to a set.

    Note: will not terminate for infinite-sized collections.

    returns

    a set containing all elements of this traversable or iterator.

    Definition Classes
    TraversableOnceGenTraversableOnce
  67. def toString (): String

    Creates a String representation of this object.

    Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.

    returns

    a String representation of the object.

    Definition Classes
    AnyRef → Any
  68. def wait (): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()
  69. def wait (arg0: Long, arg1: Int): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()
  70. def wait (arg0: Long): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()

Inherited from GenTraversableOnce[A]

Inherited from AnyRef

Inherited from Any