Packages

sealed abstract class Option[+A] extends Product with Serializable

Represents optional values. Instances of Option are either an instance of scala.Some or the object None.

The most idiomatic way to use an scala.Option instance is to treat it as a collection or monad and use map,flatMap, filter, or foreach:

val name: Option[String] = request getParameter "name"
val upper = name map { _.trim } filter { _.length != 0 } map { _.toUpperCase }
println(upper getOrElse "")

Note that this is equivalent to

val upper = for {
  name <- request getParameter "name"
  trimmed <- Some(name.trim)
  upper <- Some(trimmed.toUpperCase) if trimmed.length != 0
} yield upper
println(upper getOrElse "")

Because of how for comprehension works, if None is returned from request.getParameter, the entire expression results in None

This allows for sophisticated chaining of scala.Option values without having to check for the existence of a value.

A less-idiomatic way to use scala.Option values is via pattern matching:

val nameMaybe = request getParameter "name"
nameMaybe match {
  case Some(name) =>
    println(name.trim.toUppercase)
  case None =>
    println("No name value")
}
Self Type
Option[A]
Annotations
@SerialVersionUID()
Source
Option.scala
Version

1.1, 16/01/2007

Note

Many of the methods in here are duplicative with those in the Traversable hierarchy, but they are duplicated for a reason: the implicit conversion tends to leave one with an Iterable in situations where one could have retained an Option.

Linear Supertypes
Serializable, java.io.Serializable, Product, Equals, AnyRef, Any
Known Subclasses
Ordering
  1. Alphabetic
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Inherited
  1. Option
  2. Serializable
  3. Serializable
  4. Product
  5. Equals
  6. AnyRef
  7. Any
Implicitly
  1. by option2Iterable
  2. by any2stringadd
  3. by StringFormat
  4. by Ensuring
  5. by ArrowAssoc
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. All

Type Members

  1. class WithFilter extends AnyRef

    We need a whole WithFilter class to honor the "doesn't create a new collection" contract even though it seems unlikely to matter much in a collection with max size 1.

Abstract Value Members

  1. abstract def canEqual(that: Any): Boolean

    A method that should be called from every well-designed equals method that is open to be overridden in a subclass.

    A method that should be called from every well-designed equals method that is open to be overridden in a subclass. See Programming in Scala, Chapter 28 for discussion and design.

    that

    the value being probed for possible equality

    returns

    true if this instance can possibly equal that, otherwise false

    Definition Classes
    Equals
  2. abstract def get: A

    Returns the option's value.

    Returns the option's value.

    Exceptions thrown

    java.util.NoSuchElementException if the option is empty.

    Note

    The option must be nonempty.

  3. abstract def isEmpty: Boolean

    Returns true if the option is None, false otherwise.

  4. abstract def productArity: Int

    The size of this product.

    The size of this product.

    returns

    for a product A(x1, ..., xk), returns k

    Definition Classes
    Product
  5. abstract def productElement(n: Int): Any

    The nth element of this product, 0-based.

    The nth element of this product, 0-based. In other words, for a product A(x1, ..., xk), returns x(n+1) where 0 <= n < k.

    n

    the index of the element to return

    returns

    the element n elements after the first element

    Definition Classes
    Product
    Exceptions thrown

Concrete Value Members

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

    Test two objects for inequality.

    Test two objects for inequality.

    returns

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

    Definition Classes
    AnyRef → 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
    AnyRef → Any
  3. def +(other: String): String
    Implicit
    This member is added by an implicit conversion from Option[A] to any2stringadd[Option[A]] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ++[B >: A, That](that: GenTraversableOnce[B])(implicit bf: CanBuildFrom[collection.Iterable[A], B, That]): That

    Returns a new iterable collection containing the elements from the left hand operand followed by the elements from the right hand operand.

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

    B

    the element type of the returned collection.

    That

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

    that

    the traversable to append.

    bf

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

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLikeGenTraversableLike
  5. def ++:[B >: A, That](that: collection.Traversable[B])(implicit bf: CanBuildFrom[collection.Iterable[A], B, That]): That

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

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

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

    Example:

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

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

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

    B

    the element type of the returned collection.

    That

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

    that

    the traversable to append.

    bf

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

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLike
  6. def ++:[B](that: collection.TraversableOnce[B]): Option[B]

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

    [use case]

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

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

    Example:

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

    the element type of the returned collection.

    that

    the traversable to append.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLike
    Full Signature

    def ++:[B >: A, That](that: collection.TraversableOnce[B])(implicit bf: CanBuildFrom[collection.Iterable[A], B, That]): That

  7. def ->[B](y: B): (Option[A], B)
    Implicit
    This member is added by an implicit conversion from Option[A] to ArrowAssoc[Option[A]] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  8. def /:[B](z: B)(op: (B, A) ⇒ B): B

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

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

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

    Examples:

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

    scala> val a = List(1,2,3,4)
    a: List[Int] = List(1, 2, 3, 4)
    
    scala> val b = (5 /: a)(_+_)
    b: Int = 15
    
    scala> val c = (5 /: a)((x,y) => x + y)
    c: Int = 15

    Note: will not terminate for infinite-sized collections.

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

    B

    the result type of the binary operator.

    z

    the start value.

    op

    the binary operator.

    returns

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

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

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
  9. def :\[B](z: B)(op: (A, B) ⇒ B): B

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

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

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

    Note: will not terminate for infinite-sized collections.

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

    Examples:

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

    scala> val a = List(1,2,3,4)
    a: List[Int] = List(1, 2, 3, 4)
    
    scala> val b = (a :\ 5)(_+_)
    b: Int = 15
    
    scala> val c = (a :\ 5)((x,y) => x + y)
    c: Int = 15
    B

    the result type of the binary operator.

    z

    the start value

    op

    the binary operator

    returns

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

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

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
  10. final def ==(arg0: Any): Boolean

    The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

    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
    AnyRef → Any
  11. def addString(b: StringBuilder): StringBuilder

    Appends all elements of this iterable collection to a string builder.

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

    Example:

    scala> val a = List(1,2,3,4)
    a: List[Int] = List(1, 2, 3, 4)
    
    scala> val b = new StringBuilder()
    b: StringBuilder =
    
    scala> val h = a.addString(b)
    h: StringBuilder = 1234
    b

    the string builder to which elements are appended.

    returns

    the string builder b to which elements were appended.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnce
  12. def addString(b: StringBuilder, sep: String): StringBuilder

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

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

    Example:

    scala> val a = List(1,2,3,4)
    a: List[Int] = List(1, 2, 3, 4)
    
    scala> val b = new StringBuilder()
    b: StringBuilder =
    
    scala> a.addString(b, ", ")
    res0: StringBuilder = 1, 2, 3, 4
    b

    the string builder to which elements are appended.

    sep

    the separator string.

    returns

    the string builder b to which elements were appended.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnce
  13. def addString(b: StringBuilder, start: String, sep: String, end: String): StringBuilder

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

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

    Example:

    scala> val a = List(1,2,3,4)
    a: List[Int] = List(1, 2, 3, 4)
    
    scala> val b = new StringBuilder()
    b: StringBuilder =
    
    scala> a.addString(b , "List(" , ", " , ")")
    res5: StringBuilder = List(1, 2, 3, 4)
    b

    the string builder to which elements are appended.

    start

    the starting string.

    sep

    the separator string.

    end

    the ending string.

    returns

    the string builder b to which elements were appended.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnce
  14. def aggregate[B](z: ⇒ B)(seqop: (B, A) ⇒ B, combop: (B, B) ⇒ B): B

    Aggregates the results of applying an operator to subsequent elements.

    Aggregates the results of applying an operator to subsequent elements.

    This is a more general form of fold and reduce. It 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 iterable collection 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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
  15. 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

    the receiver object.

    Definition Classes
    Any
    Exceptions thrown

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

  16. 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[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
    Note

    not specified by SLS as a member of AnyRef

  17. final def collect[B](pf: PartialFunction[A, B]): Option[B]

    Returns a scala.Some containing the result of applying pf to this scala.Option's contained value, if this option is nonempty and pf is defined for that value.

    Returns a scala.Some containing the result of applying pf to this scala.Option's contained value, if this option is nonempty and pf is defined for that value. Returns None otherwise.

    pf

    the partial function.

    returns

    the result of applying pf to this scala.Option's value (if possible), or None.

    Annotations
    @inline()
    Example:
    1. // Returns Some(HTTP) because the partial function covers the case.
      Some("http") collect {case "http" => "HTTP"}
      
      // Returns None because the partial function doesn't cover the case.
      Some("ftp") collect {case "http" => "HTTP"}
      
      // Returns None because the option is empty. There is no value to pass to the partial function.
      None collect {case value => value}
  18. def collectFirst[B](pf: PartialFunction[A, B]): Option[B]

    Finds the first element of the iterable collection for which the given partial function is defined, and applies the partial function to it.

    Finds the first element of the iterable collection 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.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnce
    Example:
    1. Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)

  19. def companion: GenericCompanion[collection.Iterable]

    The factory companion object that builds instances of class Iterable.

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableGenericTraversableTemplateGenTraversableTraversableGenIterable
  20. final def contains[A1 >: A](elem: A1): Boolean

    Tests whether the option contains a given value as an element.

    Tests whether the option contains a given value as an element.

    elem

    the element to test.

    returns

    true if the option has an element that is equal (as determined by ==) to elem, false otherwise.

    Example:
    1. // Returns true because Some instance contains string "something" which equals "something".
      Some("something") contains "something"
      
      // Returns false because "something" != "anything".
      Some("something") contains "anything"
      
      // Returns false when method called on None.
      None contains "anything"
  21. def copyToArray(xs: Array[A], start: Int, len: Int): Unit

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

    [use case]

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

    xs

    the array to fill.

    start

    the starting index.

    len

    the maximal number of elements to copy.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLikeGenTraversableOnceTraversableOnceTraversableLike
    Full Signature

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

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

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

    [use case]

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

    xs

    the array to fill.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

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

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

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

    [use case]

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

    xs

    the array to fill.

    start

    the starting index.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

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

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

    Copies all elements of this iterable collection to a buffer.

    Copies all elements of this iterable collection to a buffer.

    Note: will not terminate for infinite-sized collections.

    dest

    The buffer to which elements are copied.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnce
  25. def count(p: (A) ⇒ Boolean): Int

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

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

    p

    the predicate used to test elements.

    returns

    the number of elements satisfying the predicate p.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
  26. def drop(n: Int): collection.Iterable[A]

    Selects all elements except first n ones.

    Selects all elements except first n ones.

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

    n

    the number of elements to drop from this iterable collection.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLikeGenTraversableLikeTraversableLike
  27. def dropRight(n: Int): collection.Iterable[A]

    Selects all elements except last n ones.

    Selects all elements except last n ones.

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

    n

    The number of elements to take

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLike
  28. def dropWhile(p: (A) ⇒ Boolean): collection.Iterable[A]

    Drops longest prefix of elements that satisfy a predicate.

    Drops longest prefix of elements that satisfy a predicate.

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

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLikeGenTraversableLike
  29. def ensuring(cond: (Option[A]) ⇒ Boolean, msg: ⇒ Any): Option[A]
    Implicit
    This member is added by an implicit conversion from Option[A] to Ensuring[Option[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  30. def ensuring(cond: (Option[A]) ⇒ Boolean): Option[A]
    Implicit
    This member is added by an implicit conversion from Option[A] to Ensuring[Option[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  31. def ensuring(cond: Boolean, msg: ⇒ Any): Option[A]
    Implicit
    This member is added by an implicit conversion from Option[A] to Ensuring[Option[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  32. def ensuring(cond: Boolean): Option[A]
    Implicit
    This member is added by an implicit conversion from Option[A] to Ensuring[Option[A]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  33. final def eq(arg0: AnyRef): Boolean

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

    Tests whether the argument (that) 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.

    Definition Classes
    AnyRef
  34. def equals(arg0: Any): Boolean

    The equality method for reference types.

    The equality method for reference types. Default implementation delegates to eq.

    See also equals in scala.Any.

    returns

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

    Definition Classes
    AnyRef → Any
  35. final def exists(p: (A) ⇒ Boolean): Boolean

    Returns true if this option is nonempty and the predicate p returns true when applied to this scala.Option's value.

    Returns true if this option is nonempty and the predicate p returns true when applied to this scala.Option's value. Otherwise, returns false.

    p

    the predicate to test

    Annotations
    @inline()
  36. final def filter(p: (A) ⇒ Boolean): Option[A]

    Returns this scala.Option if it is nonempty and applying the predicate p to this scala.Option's value returns true.

    Returns this scala.Option if it is nonempty and applying the predicate p to this scala.Option's value returns true. Otherwise, return None.

    p

    the predicate used for testing.

    Annotations
    @inline()
  37. final def filterNot(p: (A) ⇒ Boolean): Option[A]

    Returns this scala.Option if it is nonempty and applying the predicate p to this scala.Option's value returns false.

    Returns this scala.Option if it is nonempty and applying the predicate p to this scala.Option's value returns false. Otherwise, return None.

    p

    the predicate used for testing.

    Annotations
    @inline()
  38. 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[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
    Note

    not specified by SLS as a member of AnyRef

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

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

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

    Note: may not terminate for infinite-sized collections.

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

    p

    the predicate used to test elements.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLikeGenTraversableOnceTraversableOnceTraversableLike
  40. final def flatMap[B](f: (A) ⇒ Option[B]): Option[B]

    Returns the result of applying f to this scala.Option's value if this scala.Option is nonempty.

    Returns the result of applying f to this scala.Option's value if this scala.Option is nonempty. Returns None if this scala.Option is empty. Slightly different from map in that f is expected to return an scala.Option (which could be None).

    f

    the function to apply

    Annotations
    @inline()
    See also

    foreach

    map

  41. def flatten[B](implicit ev: <:<[A, Option[B]]): Option[B]
  42. final def fold[B](ifEmpty: ⇒ B)(f: (A) ⇒ B): B

    Returns the result of applying f to this scala.Option's value if the scala.Option is nonempty.

    Returns the result of applying f to this scala.Option's value if the scala.Option is nonempty. Otherwise, evaluates expression ifEmpty.

    ifEmpty

    the expression to evaluate if empty.

    f

    the function to apply if nonempty.

    Annotations
    @inline()
    Note

    This is equivalent to scala.Option map f getOrElse ifEmpty.

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

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

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

    Note: will not terminate for infinite-sized collections.

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

    B

    the result type of the binary operator.

    z

    the start value.

    op

    the binary operator.

    returns

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

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

    where x1, ..., xn are the elements of this iterable collection. Returns z if this iterable collection is empty.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
  44. def foldRight[B](z: B)(op: (A, B) ⇒ B): B

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

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

    Note: will not terminate for infinite-sized collections.

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

    B

    the result type of the binary operator.

    z

    the start value.

    op

    the binary operator.

    returns

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

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

    where x1, ..., xn are the elements of this iterable collection. Returns z if this iterable collection is empty.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLikeGenTraversableOnceTraversableOnce
  45. final def forall(p: (A) ⇒ Boolean): Boolean

    Returns true if this option is empty or the predicate p returns true when applied to this scala.Option's value.

    Returns true if this option is empty or the predicate p returns true when applied to this scala.Option's value.

    p

    the predicate to test

    Annotations
    @inline()
  46. final def foreach[U](f: (A) ⇒ U): Unit

    Apply the given procedure f to the option's value, if it is nonempty.

    Apply the given procedure f to the option's value, if it is nonempty. Otherwise, do nothing.

    f

    the procedure to apply.

    Annotations
    @inline()
    See also

    flatMap

    map

  47. def formatted(fmtstr: String): String

    Returns string formatted according to given format string.

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

    Implicit
    This member is added by an implicit conversion from Option[A] to StringFormat[Option[A]] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()
  48. def genericBuilder[B]: Builder[B, collection.Iterable[B]]

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

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    GenericTraversableTemplate
  49. final 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
    AnyRef → Any
  50. final def getOrElse[B >: A](default: ⇒ B): B

    Returns the option's value if the option is nonempty, otherwise return the result of evaluating default.

    Returns the option's value if the option is nonempty, otherwise return the result of evaluating default.

    default

    the default expression.

    Annotations
    @inline()
  51. def groupBy[K](f: (A) ⇒ K): Map[K, collection.Iterable[A]]

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

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

    K

    the type of keys returned by the discriminator function.

    f

    the discriminator function.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLikeGenTraversableLike
  52. def grouped(size: Int): collection.Iterator[collection.Iterable[A]]

    Partitions elements in fixed size iterable collections.

    Partitions elements in fixed size iterable collections.

    size

    the number of elements per group

    returns

    An iterator producing iterable collections of size size, except the last will be less than size size if the elements don't divide evenly.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLike
    See also

    scala.collection.Iterator, method grouped

  53. def hasDefiniteSize: Boolean

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

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLikeGenTraversableOnceTraversableOnce
  54. def hashCode(): Int

    The hashCode method for reference types.

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

    returns

    the hash code value for this object.

    Definition Classes
    AnyRef → Any
  55. def head: A

    Selects the first element of this iterable collection.

    Selects the first element of this iterable collection.

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

    returns

    the first element of this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLikeGenTraversableLikeTraversableLike
    Exceptions thrown

    NoSuchElementException if the iterable collection is empty.

  56. def headOption: Option[A]

    Optionally selects the first element.

    Optionally selects the first element.

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

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLikeGenTraversableLike
  57. def init: collection.Iterable[A]

    Selects all elements except the last.

    Selects all elements except the last.

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

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLikeGenTraversableLike
    Exceptions thrown

    UnsupportedOperationException if the iterable collection is empty.

  58. def inits: collection.Iterator[collection.Iterable[A]]

    Iterates over the inits of this iterable collection.

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

    returns

    an iterator over all the inits of this iterable collection

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLike
    Example:
    1. List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)

  59. def isDefined: Boolean

    Returns true if the option is an instance of scala.Some, false otherwise.

  60. final 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.

    Definition Classes
    Any
  61. final def isTraversableAgain: Boolean

    Tests whether this iterable collection can be repeatedly traversed.

    Tests whether this iterable collection can be repeatedly traversed.

    returns

    true

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLikeGenTraversableOnceGenTraversableLike
  62. def iterator: Iterator[A]

    Returns a singleton iterator returning the scala.Option's value if it is nonempty, or an empty iterator if the option is empty.

  63. 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 iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLikeGenTraversableLike
    Exceptions thrown

    NoSuchElementException If the iterable collection is empty.

  64. 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 iterable collection$ if it is nonempty, None if it is empty.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLikeGenTraversableLike
  65. final def map[B](f: (A) ⇒ B): Option[B]

    Returns a scala.Some containing the result of applying f to this scala.Option's value if this scala.Option is nonempty.

    Returns a scala.Some containing the result of applying f to this scala.Option's value if this scala.Option is nonempty. Otherwise return None.

    f

    the function to apply

    Annotations
    @inline()
    Note

    This is similar to flatMap except here, f does not need to wrap its result in an scala.Option.

    See also

    foreach

    flatMap

  66. def max: A

    [use case] Finds the largest element.

    [use case]

    Finds the largest element.

    returns

    the largest element of this option.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

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

  67. 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 option with the largest value measured by function f.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

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

  68. def min: A

    [use case] Finds the smallest element.

    [use case]

    Finds the smallest element.

    returns

    the smallest element of this option

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

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

  69. 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 option with the smallest value measured by function f.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

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

  70. def mkString: String

    Displays all elements of this iterable collection in a string.

    Displays all elements of this iterable collection in a string.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
  71. def mkString(sep: String): String

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

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

    sep

    the separator string.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
    Example:
    1. List(1, 2, 3).mkString("|") = "1|2|3"

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

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

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

    start

    the starting string.

    sep

    the separator string.

    end

    the ending string.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
    Example:
    1. List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"

  73. final 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.

    Definition Classes
    AnyRef
  74. final def nonEmpty: Boolean

    Returns false if the option is None, true otherwise.

    Returns false if the option is None, true otherwise.

    Note

    Implemented here to avoid the implicit conversion to Iterable.

  75. final 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.

    Definition Classes
    AnyRef
    Note

    not specified by SLS as a member of AnyRef

  76. final 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.

    Definition Classes
    AnyRef
    Note

    not specified by SLS as a member of AnyRef

  77. final def orElse[B >: A](alternative: ⇒ Option[B]): Option[B]

    Returns this scala.Option if it is nonempty, otherwise return the result of evaluating alternative.

    Returns this scala.Option if it is nonempty, otherwise return the result of evaluating alternative.

    alternative

    the alternative expression.

    Annotations
    @inline()
  78. final def orNull[A1 >: A](implicit ev: <:<[Null, A1]): A1

    Returns the option's value if it is nonempty, or null if it is empty.

    Returns the option's value if it is nonempty, or null if it is empty. Although the use of null is discouraged, code written to use scala.Option must often interface with code that expects and returns nulls.

    Annotations
    @inline()
    Example:
    1. val initialText: Option[String] = getInitialText
      val textField = new JComponent(initialText.orNull,20)
  79. 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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    Parallelizable
  80. def partition(p: (A) ⇒ Boolean): (collection.Iterable[A], collection.Iterable[A])

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

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

    p

    the predicate on which to partition.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLikeGenTraversableLike
  81. 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 option 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 option and as result type of product. Examples of such types are: Long, Float, Double, BigInt.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
    Full Signature

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

  82. def productIterator: Iterator[Any]

    An iterator over all the elements of this product.

    An iterator over all the elements of this product.

    returns

    in the default implementation, an Iterator[Any]

    Definition Classes
    Product
  83. def productPrefix: String

    A string used in the toString methods of derived classes.

    A string used in the toString methods of derived classes. Implementations may override this method to prepend a string prefix to the result of toString methods.

    returns

    in the default implementation, the empty string

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

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

    Reduces the elements of this iterable collection 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 iterable collection is nonempty.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
    Exceptions thrown

    UnsupportedOperationException if this iterable collection is empty.

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

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

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

    Note: will not terminate for infinite-sized collections.

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

    B

    the result type of the binary operator.

    op

    the binary operator.

    returns

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

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

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnce
    Exceptions thrown

    UnsupportedOperationException if this iterable collection is empty.

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

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

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

    Note: will not terminate for infinite-sized collections.

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

    B

    the result type of the binary operator.

    op

    the binary operator.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  87. def reduceOption[A1 >: A](op: (A1, A1) ⇒ A1): Option[A1]

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

    Reduces the elements of this iterable collection, 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.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  88. def reduceRight[B >: A](op: (A, B) ⇒ B): B

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

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

    Note: will not terminate for infinite-sized collections.

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

    B

    the result type of the binary operator.

    op

    the binary operator.

    returns

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

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

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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    Exceptions thrown

    UnsupportedOperationException if this iterable collection is empty.

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

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

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

    Note: will not terminate for infinite-sized collections.

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

    B

    the result type of the binary operator.

    op

    the binary operator.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  90. def repr: collection.Iterable[A]

    The collection of type iterable collection underlying this TraversableLike object.

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  91. def sameElements(that: GenIterable[A]): Boolean

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

    [use case]

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

    that

    the collection to compare with.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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    Full Signature

    def sameElements[B >: A](that: GenIterable[B]): Boolean

  92. def scan[B >: A, That](z: B)(op: (B, B) ⇒ B)(implicit cbf: CanBuildFrom[collection.Iterable[A], B, That]): That

    Computes a prefix scan of the elements of the collection.

    Computes a prefix scan of the elements of the collection.

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

    B

    element type of the resulting collection

    That

    type of the resulting collection

    z

    neutral element for the operator op

    op

    the associative operator for the scan

    cbf

    combiner factory which provides a combiner

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  93. def scanLeft[B, That](z: B)(op: (B, A) ⇒ B)(implicit bf: CanBuildFrom[collection.Iterable[A], B, That]): That

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

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

    Note: will not terminate for infinite-sized collections.

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

    B

    the type of the elements in the resulting collection

    That

    the actual type of the resulting collection

    z

    the initial value

    op

    the binary operator applied to the intermediate result and the element

    bf

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

    returns

    collection with intermediate results

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  94. def scanRight[B, That](z: B)(op: (A, B) ⇒ B)(implicit bf: CanBuildFrom[collection.Iterable[A], B, That]): That

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

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

    Note: will not terminate for infinite-sized collections.

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

    Example:

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

    the type of the elements in the resulting collection

    That

    the actual type of the resulting collection

    z

    the initial value

    op

    the binary operator applied to the intermediate result and the element

    bf

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

    returns

    collection with intermediate results

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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    Annotations
    @migration
    Migration

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

  95. def seq: collection.Iterable[A]

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

    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.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  96. def size: Int

    The size of this iterable collection.

    The size of this iterable collection.

    Note: will not terminate for infinite-sized collections.

    returns

    the number of elements in this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  97. def slice(from: Int, until: Int): collection.Iterable[A]

    Selects an interval of elements.

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

    from <= indexOf(x) < until

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

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  98. def sliding(size: Int, step: Int): collection.Iterator[collection.Iterable[A]]

    Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.)

    Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.)

    size

    the number of elements per group

    step

    the distance between the first elements of successive groups

    returns

    An iterator producing iterable collections of size size, except the last element (which may be the only element) will be truncated if there are fewer than size elements remaining to be grouped.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLike
    See also

    scala.collection.Iterator, method sliding

  99. def sliding(size: Int): collection.Iterator[collection.Iterable[A]]

    Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.) The "sliding window" step is set to one.

    Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.) The "sliding window" step is set to one.

    size

    the number of elements per group

    returns

    An iterator producing iterable collections of size size, except the last element (which may be the only element) will be truncated if there are fewer than size elements remaining to be grouped.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLike
    See also

    scala.collection.Iterator, method sliding

  100. def span(p: (A) ⇒ Boolean): (collection.Iterable[A], collection.Iterable[A])

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

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

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

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

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  101. def splitAt(n: Int): (collection.Iterable[A], collection.Iterable[A])

    Splits this iterable collection into two at a given position.

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  102. def stringPrefix: String

    Defines the prefix of this object's toString representation.

    Defines the prefix of this object's toString representation.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  103. 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 option 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 option and as result type of sum. Examples of such types are: Long, Float, Double, BigInt.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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    Full Signature

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

  104. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  105. def tail: collection.Iterable[A]

    Selects all elements except the first.

    Selects all elements except the first.

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

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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    Exceptions thrown

    `UnsupportedOperationException` if the iterable collection is empty.

  106. def tails: collection.Iterator[collection.Iterable[A]]

    Iterates over the tails of this iterable collection.

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

    returns

    an iterator over all the tails of this iterable collection

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLike
    Example:
    1. List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)

  107. def take(n: Int): collection.Iterable[A]

    Selects first n elements.

    Selects first n elements.

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

    n

    the number of elements to take from this iterable collection.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  108. def takeRight(n: Int): collection.Iterable[A]

    Selects last n elements.

    Selects last n elements.

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

    n

    the number of elements to take

    returns

    a iterable collection consisting only of the last n elements of this iterable collection, or else the whole iterable collection, if it has less than n elements.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLike
  109. def takeWhile(p: (A) ⇒ Boolean): collection.Iterable[A]

    Takes longest prefix of elements that satisfy a predicate.

    Takes longest prefix of elements that satisfy a predicate.

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

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  110. def to[Col[_]]: Col[A]

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

    [use case]

    Converts this option into another by copying all elements.

    Col

    The collection type to build.

    returns

    a new collection containing all elements of this option.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLikeGenTraversableOnceTraversableOnce
    Full Signature

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

  111. def toArray: Array[A]

    [use case] Converts this option to an array.

    [use case]

    Converts this option to an array.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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    Full Signature

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

  112. def toBuffer[B >: A]: Buffer[B]

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

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

    Note: will not terminate for infinite-sized collections.

    returns

    a buffer containing all elements of this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  113. def toIndexedSeq: collection.immutable.IndexedSeq[A]

    Converts this iterable collection to an indexed sequence.

    Converts this iterable collection to an indexed sequence.

    Note: will not terminate for infinite-sized collections.

    returns

    an indexed sequence containing all elements of this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  114. def toIterable: collection.Iterable[A]

    Returns this iterable collection as an iterable collection.

    Returns this iterable collection as an iterable collection.

    A new collection will not be built; lazy collections will stay lazy.

    Note: will not terminate for infinite-sized collections.

    returns

    an Iterable containing all elements of this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  115. def toIterator: collection.Iterator[A]

    Returns an Iterator over the elements in this iterable collection.

    Returns an Iterator over the elements in this iterable collection. Produces the same result as iterator.

    Note: will not terminate for infinite-sized collections.

    returns

    an Iterator containing all elements of this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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    Annotations
    @deprecatedOverriding( message = ... , since = "2.11.0" )
  116. final def toLeft[X](right: ⇒ X): Either[A, X]

    Returns a scala.util.Right containing the given argument right if this is empty, or a scala.util.Left containing this scala.Option's value if this scala.Option is nonempty.

    Returns a scala.util.Right containing the given argument right if this is empty, or a scala.util.Left containing this scala.Option's value if this scala.Option is nonempty.

    right

    the expression to evaluate and return if this is empty

    Annotations
    @inline()
    See also

    toRight

  117. def toList: List[A]

    Returns a singleton list containing the scala.Option's value if it is nonempty, or the empty list if the scala.Option is empty.

  118. def toMap[T, U]: Map[T, U]

    [use case] Converts this option to a map.

    [use case]

    Converts this option 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.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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    Full Signature

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

  119. final def toRight[X](left: ⇒ X): Either[X, A]

    Returns a scala.util.Left containing the given argument left if this scala.Option is empty, or a scala.util.Right containing this scala.Option's value if this is nonempty.

    Returns a scala.util.Left containing the given argument left if this scala.Option is empty, or a scala.util.Right containing this scala.Option's value if this is nonempty.

    left

    the expression to evaluate and return if this is empty

    Annotations
    @inline()
    See also

    toLeft

  120. def toSeq: collection.Seq[A]

    Converts this iterable collection to a sequence.

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

    Note: will not terminate for infinite-sized collections.

    returns

    a sequence containing all elements of this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  121. def toSet[B >: A]: Set[B]

    Converts this iterable collection to a set.

    Converts this iterable collection to a set.

    Note: will not terminate for infinite-sized collections.

    returns

    a set containing all elements of this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
  122. def toStream: collection.immutable.Stream[A]

    Converts this iterable collection to a stream.

    Converts this iterable collection to a stream.

    returns

    a stream containing all elements of this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  123. 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
  124. def toTraversable: collection.Traversable[A]

    Converts this iterable collection to an unspecified Traversable.

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

    Note: will not terminate for infinite-sized collections.

    returns

    a Traversable containing all elements of this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableLikeGenTraversableOnceTraversableOnce
    Annotations
    @deprecatedOverriding( message = ... , since = "2.11.0" )
  125. def toVector: Vector[A]

    Converts this iterable collection to a Vector.

    Converts this iterable collection to a Vector.

    Note: will not terminate for infinite-sized collections.

    returns

    a vector containing all elements of this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    TraversableOnceGenTraversableOnce
  126. def transpose[B](implicit asTraversable: (A) ⇒ GenTraversableOnce[B]): collection.Iterable[collection.Iterable[B]]

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

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

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

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

    the type of the elements of each traversable collection.

    asTraversable

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

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    GenericTraversableTemplate
    Annotations
    @migration
    Migration

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

    Exceptions thrown

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

  127. def unzip[A1, A2](implicit asPair: (A) ⇒ (A1, A2)): (collection.Iterable[A1], collection.Iterable[A2])

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

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

    val xs = Iterable(
               (1, "one"),
               (2, "two"),
               (3, "three")).unzip
    // xs == (Iterable(1, 2, 3),
    //        Iterable(one, two, three))
    A1

    the type of the first half of the element pairs

    A2

    the type of the second half of the element pairs

    asPair

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

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    GenericTraversableTemplate
  128. def unzip3[A1, A2, A3](implicit asTriple: (A) ⇒ (A1, A2, A3)): (collection.Iterable[A1], collection.Iterable[A2], collection.Iterable[A3])

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

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

    val xs = Iterable(
               (1, "one", '1'),
               (2, "two", '2'),
               (3, "three", '3')).unzip3
    // xs == (Iterable(1, 2, 3),
    //        Iterable(one, two, three),
    //        Iterable(1, 2, 3))
    A1

    the type of the first member of the element triples

    A2

    the type of the second member of the element triples

    A3

    the type of the third member of the element triples

    asTriple

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

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    GenericTraversableTemplate
  129. def view(from: Int, until: Int): IterableView[A, collection.Iterable[A]]

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

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

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

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

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

    from

    the index of the first element of the view

    until

    the index of the element following the view

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLikeTraversableLike
  130. def view: IterableView[A, collection.Iterable[A]]

    Creates a non-strict view of this iterable collection.

    Creates a non-strict view of this iterable collection.

    returns

    a non-strict view of this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
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  131. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  132. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  133. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  134. final def withFilter(p: (A) ⇒ Boolean): WithFilter

    Necessary to keep scala.Option from being implicitly converted to scala.collection.Iterable in for comprehensions.

    Necessary to keep scala.Option from being implicitly converted to scala.collection.Iterable in for comprehensions.

    Annotations
    @inline()
  135. def zip[B](that: GenIterable[B]): Option[(A, B)]

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

    [use case]

    Returns a option formed from this option 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.

    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 option containing pairs consisting of corresponding elements of this option and that. The length of the returned collection is the minimum of the lengths of this option and that.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLikeGenIterableLike
    Full Signature

    def zip[A1 >: A, B, That](that: GenIterable[B])(implicit bf: CanBuildFrom[collection.Iterable[A], (A1, B), That]): That

  136. def zipAll[B](that: collection.Iterable[B], thisElem: A, thatElem: B): Option[(A, B)]

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

    [use case]

    Returns a option formed from this option 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.

    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 option is shorter than that.

    thatElem

    the element to be used to fill up the result if that is shorter than this option.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLikeGenIterableLike
    Full Signature

    def zipAll[B, A1 >: A, That](that: GenIterable[B], thisElem: A1, thatElem: B)(implicit bf: CanBuildFrom[collection.Iterable[A], (A1, B), That]): That

  137. def zipWithIndex: Option[(A, Int)]

    [use case] Zips this option with its indices.

    [use case]

    Zips this option with its indices.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Definition Classes
    IterableLikeGenIterableLike
    Full Signature

    def zipWithIndex[A1 >: A, That](implicit bf: CanBuildFrom[collection.Iterable[A], (A1, Int), That]): That

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

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

Shadowed Implicit Value Members

  1. def canEqual(that: Any): Boolean

    Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.

    Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.

    that

    The object with which this iterable collection should be compared

    returns

    true, if this iterable collection can possibly equal that, false otherwise. The test takes into consideration only the run-time types of objects but ignores their elements.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (option: Iterable[A]).canEqual(that)
    Definition Classes
    IterableLikeEquals
  2. def collect[B](pf: PartialFunction[A, B]): Option[B]

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

    [use case]

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

    B

    the element type of the returned collection.

    pf

    the partial function which filters and maps the option.

    returns

    a new option 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.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
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    (option: Iterable[A]).collect(pf)
    Definition Classes
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    Full Signature

    def collect[B, That](pf: PartialFunction[A, B])(implicit bf: CanBuildFrom[collection.Iterable[A], B, That]): That

  3. def exists(p: (A) ⇒ Boolean): Boolean

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

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

    Note: may not terminate for infinite-sized collections.

    p

    the predicate used to test elements.

    returns

    false if this iterable collection is empty, otherwise true if the given predicate p holds for some of the elements of this iterable collection, otherwise false

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
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    (option: Iterable[A]).exists(p)
    Definition Classes
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  4. def filter(p: (A) ⇒ Boolean): collection.Iterable[A]

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

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

    p

    the predicate used to test elements.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (option: Iterable[A]).filter(p)
    Definition Classes
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  5. def filterNot(p: (A) ⇒ Boolean): collection.Iterable[A]

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

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

    p

    the predicate used to test elements.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (option: Iterable[A]).filterNot(p)
    Definition Classes
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  6. def flatMap[B](f: (A) ⇒ GenTraversableOnce[B]): Option[B]

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

    [use case]

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (option: Iterable[A]).flatMap(f)
    Definition Classes
    TraversableLikeFilterMonadicGenTraversableLike
    Full Signature

    def flatMap[B, That](f: (A) ⇒ GenTraversableOnce[B])(implicit bf: CanBuildFrom[collection.Iterable[A], B, That]): That

  7. def flatten[B]: Option[B]

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

    [use case]

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

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

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

    the type of the elements of each traversable collection.

    returns

    a new option resulting from concatenating all element options.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (option: Iterable[A]).flatten
    Definition Classes
    GenericTraversableTemplate
    Full Signature

    def flatten[B](implicit asTraversable: (A) ⇒ GenTraversableOnce[B]): collection.Iterable[B]

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

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

    Folds the elements of this iterable collection 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 iterable collection is empty.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (option: Iterable[A]).fold(z)(op)
    Definition Classes
    TraversableOnceGenTraversableOnce
  9. def forall(p: (A) ⇒ Boolean): Boolean

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

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

    Note: may not terminate for infinite-sized collections.

    p

    the predicate used to test elements.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (option: Iterable[A]).forall(p)
    Definition Classes
    IterableLikeGenTraversableOnceTraversableOnceTraversableLike
  10. def foreach(f: (A) ⇒ Unit): Unit

    [use case] Applies a function f to all elements of this option.

    [use case]

    Applies a function f to all elements of this option.

    Note: this method underlies the implementation of most other bulk operations. Subclasses should re-implement this method if a more efficient implementation exists.

    f

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (option: Iterable[A]).foreach(f)
    Definition Classes
    IterableLikeFilterMonadicGenTraversableOnceTraversableOnceGenTraversableLikeTraversableLike
    Full Signature

    def foreach[U](f: (A) ⇒ U): Unit

  11. def isEmpty: Boolean

    Tests whether this iterable collection is empty.

    Tests whether this iterable collection is empty.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (option: Iterable[A]).isEmpty
    Definition Classes
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  12. def iterator: collection.Iterator[A]

    Creates a new iterator over all elements contained in this iterable object.

    Creates a new iterator over all elements contained in this iterable object.

    returns

    the new iterator

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (option: Iterable[A]).iterator
    Definition Classes
    IterableLikeGenIterableLike
  13. def map[B](f: (A) ⇒ B): Option[B]

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

    [use case]

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

    B

    the element type of the returned collection.

    f

    the function to apply to each element.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (option: Iterable[A]).map(f)
    Definition Classes
    TraversableLikeFilterMonadicGenTraversableLike
    Full Signature

    def map[B, That](f: (A) ⇒ B)(implicit bf: CanBuildFrom[collection.Iterable[A], B, That]): That

  14. def nonEmpty: Boolean

    Tests whether the iterable collection is not empty.

    Tests whether the iterable collection is not empty.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (option: Iterable[A]).nonEmpty
    Definition Classes
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  15. def toList: List[A]

    Converts this iterable collection to a list.

    Converts this iterable collection to a list.

    Note: will not terminate for infinite-sized collections.

    returns

    a list containing all elements of this iterable collection.

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
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    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
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    Definition Classes
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  16. def toString(): String

    Converts this iterable collection to a string.

    Converts this iterable collection to a string.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
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    This implicitly inherited member is shadowed by one or more members in this class.
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    (option: Iterable[A]).toString()
    Definition Classes
    TraversableLikeAny
  17. def withFilter(p: (A) ⇒ Boolean): FilterMonadic[A, collection.Iterable[A]]

    Creates a non-strict filter of this iterable collection.

    Creates a non-strict filter of this iterable collection.

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

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

    p

    the predicate used to test elements.

    returns

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

    Implicit
    This member is added by an implicit conversion from Option[A] to Iterable[A] performed by method option2Iterable in scala.Option.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
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    Definition Classes
    TraversableLikeFilterMonadic

Inherited from Serializable

Inherited from java.io.Serializable

Inherited from Product

Inherited from Equals

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion option2Iterable from Option[A] to Iterable[A]

Inherited by implicit conversion any2stringadd from Option[A] to any2stringadd[Option[A]]

Inherited by implicit conversion StringFormat from Option[A] to StringFormat[Option[A]]

Inherited by implicit conversion Ensuring from Option[A] to Ensuring[Option[A]]

Inherited by implicit conversion ArrowAssoc from Option[A] to ArrowAssoc[Option[A]]

Ungrouped