Scala Standard Library2.13.9 < Back


# Packages

-  package root

  This is the documentation for the Scala standard library.

  This is the documentation for the Scala standard library.

  #### Package structure

  The scala package contains core types like `Int`, `Float`, `Array` or `Option` which are accessible in all Scala compilation units without explicit qualification or imports.

  Notable packages include:

  - `scala.collection` and its sub-packages contain Scala's collections framework
    - `scala.collection.immutable` - Immutable, sequential data-structures such as `Vector`, `List`, `Range`, `HashMap` or `HashSet`
    - `scala.collection.mutable` - Mutable, sequential data-structures such as `ArrayBuffer`, `StringBuilder`, `HashMap` or `HashSet`
    - `scala.collection.concurrent` - Mutable, concurrent data-structures such as `TrieMap`
  - `scala.concurrent` - Primitives for concurrent programming such as `Futures` and `Promises`
  - `scala.io` - Input and output operations
  - `scala.math` - Basic math functions and additional numeric types like `BigInt` and `BigDecimal`
  - `scala.sys` - Interaction with other processes and the operating system
  - `scala.util.matching` - Regular expressions

  Other packages exist. See the complete list on the right.

  Additional parts of the standard library are shipped as separate libraries. These include:

  - `scala.reflect` - Scala's reflection API (scala-reflect.jar)
  - `scala.xml` - XML parsing, manipulation, and serialization (scala-xml.jar)
  - `scala.collection.parallel` - Parallel collections (scala-parallel-collections.jar)
  - `scala.util.parsing` - Parser combinators (scala-parser-combinators.jar)
  - `scala.swing` - A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)

  #### Automatic imports

  Identifiers in the scala package and the `scala.Predef` object are always in scope by default.

  Some of these identifiers are type aliases provided as shortcuts to commonly used classes. For example, `List` is an alias for `scala.collection.immutable.List`.

  Other aliases refer to classes provided by the underlying platform. For example, on the JVM, `String` is an alias for `java.lang.String`.

  Definition Classes
    root
-  package scala

  Core Scala types.

  Core Scala types. They are always available without an explicit import.

  Definition Classes
    root
-  package jdk

  The jdk package contains utilities to interact with JDK classes.

  The jdk package contains utilities to interact with JDK classes.

  This packages offers a number of converters, that are able to wrap or copy types from the scala library to equivalent types in the JDK class library and vice versa:

  - CollectionConverters, converting collections like scala.collection.Seq, scala.collection.Map, scala.collection.Set, scala.collection.mutable.Buffer, scala.collection.Iterator and scala.collection.Iterable to their JDK counterparts
  - OptionConverters, converting between Option and java.util.Optional and primitive variations
  - StreamConverters, to create JDK Streams from scala collections
  - DurationConverters, for conversions between scala scala.concurrent.duration.FiniteDuration and java.time.Duration
  - FunctionConverters, from scala Functions to java java.util.function.Function, java.util.function.UnaryOperator, java.util.function.Consumer and java.util.function.Predicate, as well as primitive variations and Bi-variations.

  By convention, converters that wrap an object to provide a different interface to the same underlying data structure use .asScala and .asJava extension methods, whereas converters that copy the underlying data structure use .toScala and .toJava.

  In the javaapi package, the same converters can be found with a java-friendly interface that don't rely on implicit enrichments.

  Additionally, this package offers Accumulators, capable of efficiently traversing JDK Streams.

  Definition Classes
    scala
-  object FunctionWrappers
  Definition Classes
    jdk
- AsJavaBiConsumer
- AsJavaBiFunction
- AsJavaBiPredicate
- AsJavaBinaryOperator
- AsJavaBooleanSupplier
- AsJavaConsumer
- AsJavaDoubleBinaryOperator
- AsJavaDoubleConsumer
- AsJavaDoubleFunction
- AsJavaDoublePredicate
- AsJavaDoubleSupplier
- AsJavaDoubleToIntFunction
- AsJavaDoubleToLongFunction
- AsJavaDoubleUnaryOperator
- AsJavaFunction
- AsJavaIntBinaryOperator
- AsJavaIntConsumer
- AsJavaIntFunction
- AsJavaIntPredicate
- AsJavaIntSupplier
- AsJavaIntToDoubleFunction
- AsJavaIntToLongFunction
- AsJavaIntUnaryOperator
- AsJavaLongBinaryOperator
- AsJavaLongConsumer
- AsJavaLongFunction
- AsJavaLongPredicate
- AsJavaLongSupplier
- AsJavaLongToDoubleFunction
- AsJavaLongToIntFunction
- AsJavaLongUnaryOperator
- AsJavaObjDoubleConsumer
- AsJavaObjIntConsumer
- AsJavaObjLongConsumer
- AsJavaPredicate
- AsJavaSupplier
- AsJavaToDoubleBiFunction
- AsJavaToDoubleFunction
- AsJavaToIntBiFunction
- AsJavaToIntFunction
- AsJavaToLongBiFunction
- AsJavaToLongFunction
- AsJavaUnaryOperator
- FromJavaBiConsumer
- FromJavaBiFunction
- FromJavaBiPredicate
- FromJavaBinaryOperator
- FromJavaBooleanSupplier
- FromJavaConsumer
- FromJavaDoubleBinaryOperator
- FromJavaDoubleConsumer
- FromJavaDoubleFunction
- FromJavaDoublePredicate
- FromJavaDoubleSupplier
- FromJavaDoubleToIntFunction
- FromJavaDoubleToLongFunction
- FromJavaDoubleUnaryOperator
- FromJavaFunction
- FromJavaIntBinaryOperator
- FromJavaIntConsumer
- FromJavaIntFunction
- FromJavaIntPredicate
- FromJavaIntSupplier
- FromJavaIntToDoubleFunction
- FromJavaIntToLongFunction
- FromJavaIntUnaryOperator
- FromJavaLongBinaryOperator
- FromJavaLongConsumer
- FromJavaLongFunction
- FromJavaLongPredicate
- FromJavaLongSupplier
- FromJavaLongToDoubleFunction
- FromJavaLongToIntFunction
- FromJavaLongUnaryOperator
- FromJavaObjDoubleConsumer
- FromJavaObjIntConsumer
- FromJavaObjLongConsumer
- FromJavaPredicate
- FromJavaSupplier
- FromJavaToDoubleBiFunction
- FromJavaToDoubleFunction
- FromJavaToIntBiFunction
- FromJavaToIntFunction
- FromJavaToLongBiFunction
- FromJavaToLongFunction
- FromJavaUnaryOperator
- RichBiConsumerAsFunction2
- RichBiFunctionAsFunction2
- RichBiPredicateAsFunction2
- RichBinaryOperatorAsFunction2
- RichBooleanSupplierAsFunction0
- RichConsumerAsFunction1
- RichDoubleBinaryOperatorAsFunction2
- RichDoubleConsumerAsFunction1
- RichDoubleFunctionAsFunction1
- RichDoublePredicateAsFunction1
- RichDoubleSupplierAsFunction0
- RichDoubleToIntFunctionAsFunction1
- RichDoubleToLongFunctionAsFunction1
- RichDoubleUnaryOperatorAsFunction1
- RichFunction0AsBooleanSupplier
- RichFunction0AsDoubleSupplier
- RichFunction0AsIntSupplier
- RichFunction0AsLongSupplier
- RichFunction0AsSupplier
- RichFunction1AsConsumer
- RichFunction1AsDoubleConsumer
- RichFunction1AsDoubleFunction
- RichFunction1AsDoublePredicate
- RichFunction1AsDoubleToIntFunction
- RichFunction1AsDoubleToLongFunction
- RichFunction1AsDoubleUnaryOperator
- RichFunction1AsFunction
- RichFunction1AsIntConsumer
- RichFunction1AsIntFunction
- RichFunction1AsIntPredicate
- RichFunction1AsIntToDoubleFunction
- RichFunction1AsIntToLongFunction
- RichFunction1AsIntUnaryOperator
- RichFunction1AsLongConsumer
- RichFunction1AsLongFunction
- RichFunction1AsLongPredicate
- RichFunction1AsLongToDoubleFunction
- RichFunction1AsLongToIntFunction
- RichFunction1AsLongUnaryOperator
- RichFunction1AsPredicate
- RichFunction1AsToDoubleFunction
- RichFunction1AsToIntFunction
- RichFunction1AsToLongFunction
- RichFunction1AsUnaryOperator
- RichFunction2AsBiConsumer
- RichFunction2AsBiFunction
- RichFunction2AsBiPredicate
- RichFunction2AsBinaryOperator
- RichFunction2AsDoubleBinaryOperator
- RichFunction2AsIntBinaryOperator
- RichFunction2AsLongBinaryOperator
- RichFunction2AsObjDoubleConsumer
- RichFunction2AsObjIntConsumer
- RichFunction2AsObjLongConsumer
- RichFunction2AsToDoubleBiFunction
- RichFunction2AsToIntBiFunction
- RichFunction2AsToLongBiFunction
- RichFunctionAsFunction1
- RichIntBinaryOperatorAsFunction2
- RichIntConsumerAsFunction1
- RichIntFunctionAsFunction1
- RichIntPredicateAsFunction1
- RichIntSupplierAsFunction0
- RichIntToDoubleFunctionAsFunction1
- RichIntToLongFunctionAsFunction1
- RichIntUnaryOperatorAsFunction1
- RichLongBinaryOperatorAsFunction2
- RichLongConsumerAsFunction1
- RichLongFunctionAsFunction1
- RichLongPredicateAsFunction1
- RichLongSupplierAsFunction0
- RichLongToDoubleFunctionAsFunction1
- RichLongToIntFunctionAsFunction1
- RichLongUnaryOperatorAsFunction1
- RichObjDoubleConsumerAsFunction2
- RichObjIntConsumerAsFunction2
- RichObjLongConsumerAsFunction2
- RichPredicateAsFunction1
- RichSupplierAsFunction0
- RichToDoubleBiFunctionAsFunction2
- RichToDoubleFunctionAsFunction1
- RichToIntBiFunctionAsFunction2
- RichToIntFunctionAsFunction1
- RichToLongBiFunctionAsFunction2
- RichToLongFunctionAsFunction1
- RichUnaryOperatorAsFunction1

c

scala.jdk.FunctionWrappers

# AsJavaFunction

###

#### case class AsJavaFunction[T, R](sf: (T) => R) extends java.util.function.Function[T, R] with Product with Serializable

Source
  FunctionWrappers.scala

Linear Supertypes
java.io.Serializable, Product, Equals, java.util.function.Function[T, R], AnyRef, Any
Type Hierarchy

Ordering

1. Alphabetic
2. By Inheritance

Inherited

1. AsJavaFunction
2. Serializable
3. Product
4. Equals
5. Function
6. AnyRef
7. Any

Implicitly

1. by any2stringadd
2. by StringFormat
3. by Ensuring
4. by ArrowAssoc

1. Hide All
2. Show All

Visibility

1. Public
2. Protected

### Instance Constructors

1.  new AsJavaFunction(sf: (T) => R)

### 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 AsJavaFunction[T, R] toany2stringadd[AsJavaFunction[T, R]] performed by method any2stringadd in scala.Predef.
   Definition Classes
     any2stringadd
4.  def ->[B](y: B): (AsJavaFunction[T, R], B)
   Implicit
     This member is added by an implicit conversion from AsJavaFunction[T, R] toArrowAssoc[AsJavaFunction[T, R]] performed by method ArrowAssoc in scala.Predef.
   Definition Classes
     ArrowAssoc
   Annotations
     @inline()
5.  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
6.  def andThen[V <: AnyRef](arg0: java.util.function.Function[_ >: R <: AnyRef, _ <: V]): java.util.function.Function[T, V]
   Definition Classes
     Function
7.  def apply(x1: T): R
   Definition Classes
     AsJavaFunction → Function
8.  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`.

9.  def clone(): AnyRef

   Create a copy of the receiver object.

   Create a copy of the receiver object.

   The default implementation of the `clone` method is platform dependent.

   returns

     a copy of the receiver object.

   Attributes
     protected[lang]
   Definition Classes
     AnyRef
   Annotations
     @throws(classOf[java.lang.CloneNotSupportedException]) @native()
   Note

     not specified by SLS as a member of AnyRef

10.  def compose[V <: AnyRef](arg0: java.util.function.Function[_ >: V <: AnyRef, _ <: T]): java.util.function.Function[V, R]
    Definition Classes
      Function
11.  def ensuring(cond: (AsJavaFunction[T, R]) => Boolean, msg: => Any): AsJavaFunction[T, R]
    Implicit
      This member is added by an implicit conversion from AsJavaFunction[T, R] toEnsuring[AsJavaFunction[T, R]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
12.  def ensuring(cond: (AsJavaFunction[T, R]) => Boolean): AsJavaFunction[T, R]
    Implicit
      This member is added by an implicit conversion from AsJavaFunction[T, R] toEnsuring[AsJavaFunction[T, R]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
13.  def ensuring(cond: Boolean, msg: => Any): AsJavaFunction[T, R]
    Implicit
      This member is added by an implicit conversion from AsJavaFunction[T, R] toEnsuring[AsJavaFunction[T, R]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
14.  def ensuring(cond: Boolean): AsJavaFunction[T, R]
    Implicit
      This member is added by an implicit conversion from AsJavaFunction[T, R] toEnsuring[AsJavaFunction[T, R]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
15.  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
16.  def finalize(): Unit

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

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

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

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

      not specified by SLS as a member of AnyRef

17.  final def getClass(): Class[_ <: AnyRef]

    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
    Annotations
      @native()
18.  final def isInstanceOf[T0]: Boolean

    Test whether the dynamic type of the receiver object has the same erasure as `T0`.

    Test whether the dynamic type of the receiver object has the same erasure as `T0`.

    Depending on what `T0` is, the test is done in one of the below ways:

    - `T0` is a non-parameterized class type, e.g. `BigDecimal`: this method returns `true` if the value of the receiver object is a `BigDecimal` or a subtype of `BigDecimal`.
    - `T0` is a parameterized class type, e.g. `List[Int]`: this method returns `true` if the value of the receiver object is some `List[X]` for any `X`. For example, `List(1, 2, 3).isInstanceOf[List[String]]` will return true.
    - `T0` is some singleton type `x.type` or literal `x`: this method returns `this.eq(x)`. For example, `x.isInstanceOf[1]` is equivalent to `x.eq(1)`
    - `T0` is an intersection `X with Y` or `X & Y: this method is equivalent to` x.isInstanceOf[X] && x.isInstanceOf[Y]``
    - `T0` is a union `X | Y`: this method is equivalent to `x.isInstanceOf[X] || x.isInstanceOf[Y]`
    - `T0` is a type parameter or an abstract type member: this method is equivalent to `isInstanceOf[U]` where `U` is `T0`'s upper bound, `Any` if `T0` is unbounded. For example, `x.isInstanceOf[A]` where `A` is an unbounded type parameter will return true for any value of `x`.

    This is exactly equivalent to the type pattern `_: T0`

    returns

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

    Definition Classes
      Any
    Note

      due to the unexpectedness of `List(1, 2, 3).isInstanceOf[List[String]]` returning true and `x.isInstanceOf[A]` where `A` is a type parameter or abstract member returning true, these forms issue a warning.

19.  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
20.  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
    Annotations
      @native()
    Note

      not specified by SLS as a member of AnyRef

21.  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
    Annotations
      @native()
    Note

      not specified by SLS as a member of AnyRef

22.  def productElementNames: Iterator[String]

    An iterator over the names of all the elements of this product.

    An iterator over the names of all the elements of this product.

    Definition Classes
      Product
23.  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
24.  val sf: (T) => R
25.  final def synchronized[T0](arg0: => T0): T0

    Executes the code in `body` with an exclusive lock on `this`.

    Executes the code in `body` with an exclusive lock on `this`.

    returns

      the result of `body`

    Definition Classes
      AnyRef
26.  final def wait(): Unit

    See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait--.

    See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait--.

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

      not specified by SLS as a member of AnyRef

27.  final def wait(arg0: Long, arg1: Int): Unit

    See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-int-

    See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-int-

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

      not specified by SLS as a member of AnyRef

28.  final def wait(arg0: Long): Unit

    See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-.

    See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-.

    Definition Classes
      AnyRef
    Annotations
      @throws(classOf[java.lang.InterruptedException]) @native()
    Note

      not specified by SLS as a member of AnyRef

### Deprecated Value Members

1.  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 AsJavaFunction[T, R] toStringFormat[AsJavaFunction[T, R]] performed by method StringFormat in scala.Predef.
   Definition Classes
     StringFormat
   Annotations
     @deprecated @inline()
   Deprecated

     (Since version 2.12.16) Use `formatString.format(value)` instead of `value.formatted(formatString)`, or use the `f""` string interpolator. In Java 15 and later, `formatted` resolves to the new method in String which has reversed parameters.

2.  def →[B](y: B): (AsJavaFunction[T, R], B)
   Implicit
     This member is added by an implicit conversion from AsJavaFunction[T, R] toArrowAssoc[AsJavaFunction[T, R]] performed by method ArrowAssoc in scala.Predef.
   Definition Classes
     ArrowAssoc
   Annotations
     @deprecated
   Deprecated

     (Since version 2.13.0) Use `->` instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.

### Inherited from java.io.Serializable

### Inherited from Product

### Inherited from Equals

### Inherited from java.util.function.Function[T, R]

### Inherited from AnyRef

### Inherited from Any

### Inherited by implicit conversion any2stringadd fromAsJavaFunction[T, R] to any2stringadd[AsJavaFunction[T, R]]

### Inherited by implicit conversion StringFormat fromAsJavaFunction[T, R] to StringFormat[AsJavaFunction[T, R]]

### Inherited by implicit conversion Ensuring fromAsJavaFunction[T, R] to Ensuring[AsJavaFunction[T, R]]

### Inherited by implicit conversion ArrowAssoc fromAsJavaFunction[T, R] to ArrowAssoc[AsJavaFunction[T, R]]

### Ungrouped