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:

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

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

    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
  • abstract class Enumeration extends Serializable

    Defines a finite set of values specific to the enumeration.

    Defines a finite set of values specific to the enumeration. Typically these values enumerate all possible forms something can take and provide a lightweight alternative to case classes.

    Each call to a Value method adds a new unique value to the enumeration. To be accessible, these values are usually defined as val members of the enumeration.

    All values in an enumeration share a common, unique type defined as the Value type member of the enumeration (Value selected on the stable identifier path of the enumeration instance).

    Values SHOULD NOT be added to an enumeration after its construction; doing so makes the enumeration thread-unsafe. If values are added to an enumeration from multiple threads (in a non-synchronized fashion) after construction, the behavior of the enumeration is undefined.

    Definition Classes
    scala
    Annotations
    @SerialVersionUID()
    Examples:

    1. // Define a new enumeration with a type alias and work with the full set of enumerated values
object WeekDay extends Enumeration {
  type WeekDay = Value
  val Mon, Tue, Wed, Thu, Fri, Sat, Sun = Value
}
import WeekDay._

def isWorkingDay(d: WeekDay) = ! (d == Sat || d == Sun)

WeekDay.values filter isWorkingDay foreach println
// output:
// Mon
// Tue
// Wed
// Thu
// Fri
      2. , 

    2. // Example of adding attributes to an enumeration by extending the Enumeration.Val class
object Planet extends Enumeration {
  protected case class PlanetVal(mass: Double, radius: Double) extends super.Val {
    def surfaceGravity: Double = Planet.G * mass / (radius * radius)
    def surfaceWeight(otherMass: Double): Double = otherMass * surfaceGravity
  }
  import scala.language.implicitConversions
  implicit def valueToPlanetVal(x: Value): PlanetVal = x.asInstanceOf[PlanetVal]

  val G: Double = 6.67300E-11
  val Mercury = PlanetVal(3.303e+23, 2.4397e6)
  val Venus   = PlanetVal(4.869e+24, 6.0518e6)
  val Earth   = PlanetVal(5.976e+24, 6.37814e6)
  val Mars    = PlanetVal(6.421e+23, 3.3972e6)
  val Jupiter = PlanetVal(1.9e+27, 7.1492e7)
  val Saturn  = PlanetVal(5.688e+26, 6.0268e7)
  val Uranus  = PlanetVal(8.686e+25, 2.5559e7)
  val Neptune = PlanetVal(1.024e+26, 2.4746e7)
}

println(Planet.values.filter(_.radius > 7.0e6))
// output:
// Planet.ValueSet(Jupiter, Saturn, Uranus, Neptune)
  • Val
  • Value
  • ValueOrdering
  • ValueSet

abstract class Value extends Ordered[Value] with Serializable

The type of the enumerated values.

Annotations
@SerialVersionUID()
Source
Enumeration.scala
Linear Supertypes
java.io.Serializable, math.Ordered[Value], Comparable[Value], AnyRef, Any
Known Subclasses
Val
Type Hierarchy
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. Value
  2. Serializable
  3. Ordered
  4. Comparable
  5. AnyRef
  6. Any
Implicitly
  1. by orderingToOrdered
  2. by any2stringadd
  3. by StringFormat
  4. by Ensuring
  5. by ArrowAssoc
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. Protected

Instance Constructors

  1. new Value()

Abstract Value Members

  1. abstract def id: Int

    the id and bit location of this enumeration value

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 +(v: Value): ValueSet

    Create a ValueSet which contains this value and another one

  4. def ->[B](y: B): (Value, B)
    Implicit
    This member is added by an implicit conversion from Value toArrowAssoc[Value] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  5. def <(that: Value): Boolean

    Returns true if this is less than that

    Returns true if this is less than that

    Definition Classes
    Ordered
  6. def <=(that: Value): Boolean

    Returns true if this is less than or equal to that.

    Returns true if this is less than or equal to that.

    Definition Classes
    Ordered
  7. 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
  8. def >(that: Value): Boolean

    Returns true if this is greater than that.

    Returns true if this is greater than that.

    Definition Classes
    Ordered
  9. def >=(that: Value): Boolean

    Returns true if this is greater than or equal to that.

    Returns true if this is greater than or equal to that.

    Definition Classes
    Ordered
  10. 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.

  11. 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

  12. def compare(that: Value): Int

    Result of comparing this with operand that.

    Result of comparing this with operand that.

    Implement this method to determine how instances of A will be sorted.

    Returns x where:

    • x < 0 when this < that
    • x == 0 when this == that
    • x > 0 when this > that
    Definition Classes
    Value → Ordered
  13. def compareTo(that: Value): Int

    Result of comparing this with operand that.

    Result of comparing this with operand that.

    Definition Classes
    Ordered → Comparable
  14. def ensuring(cond: (Value) => Boolean, msg: => Any): Value
    Implicit
    This member is added by an implicit conversion from Value toEnsuring[Value] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  15. def ensuring(cond: (Value) => Boolean): Value
    Implicit
    This member is added by an implicit conversion from Value toEnsuring[Value] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  16. def ensuring(cond: Boolean, msg: => Any): Value
    Implicit
    This member is added by an implicit conversion from Value toEnsuring[Value] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  17. def ensuring(cond: Boolean): Value
    Implicit
    This member is added by an implicit conversion from Value toEnsuring[Value] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  18. 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
  19. def equals(other: 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
    Value → AnyRef → Any
  20. 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

  21. 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()
  22. 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
    Value → AnyRef → Any
  23. 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.

  24. 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
  25. 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

  26. 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

  27. 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
  28. 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
  29. 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

  30. 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

  31. 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

Shadowed Implicit Value Members

  1. def +(other: String): String
    Implicit
    This member is added by an implicit conversion from Value toany2stringadd[Value] performed by method any2stringadd in scala.Predef.
    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:
    (value: any2stringadd[Value]).+(other)
    Definition Classes
    any2stringadd
  2. def <(that: Value): Boolean

    Returns true if this is less than that

    Returns true if this is less than that

    Implicit
    This member is added by an implicit conversion from Value tomath.Ordered[Value] performed by method orderingToOrdered in scala.math.Ordered.This conversion will take place only if an implicit value of type math.Ordering[Value] is in scope.
    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:
    (value: math.Ordered[Value]).<(that)
    Definition Classes
    Ordered
  3. def <=(that: Value): Boolean

    Returns true if this is less than or equal to that.

    Returns true if this is less than or equal to that.

    Implicit
    This member is added by an implicit conversion from Value tomath.Ordered[Value] performed by method orderingToOrdered in scala.math.Ordered.This conversion will take place only if an implicit value of type math.Ordering[Value] is in scope.
    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:
    (value: math.Ordered[Value]).<=(that)
    Definition Classes
    Ordered
  4. def >(that: Value): Boolean

    Returns true if this is greater than that.

    Returns true if this is greater than that.

    Implicit
    This member is added by an implicit conversion from Value tomath.Ordered[Value] performed by method orderingToOrdered in scala.math.Ordered.This conversion will take place only if an implicit value of type math.Ordering[Value] is in scope.
    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:
    (value: math.Ordered[Value]).>(that)
    Definition Classes
    Ordered
  5. def >=(that: Value): Boolean

    Returns true if this is greater than or equal to that.

    Returns true if this is greater than or equal to that.

    Implicit
    This member is added by an implicit conversion from Value tomath.Ordered[Value] performed by method orderingToOrdered in scala.math.Ordered.This conversion will take place only if an implicit value of type math.Ordering[Value] is in scope.
    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:
    (value: math.Ordered[Value]).>=(that)
    Definition Classes
    Ordered
  6. def compare(that: Value): Int

    Result of comparing this with operand that.

    Result of comparing this with operand that.

    Implement this method to determine how instances of A will be sorted.

    Returns x where:

    • x < 0 when this < that
    • x == 0 when this == that
    • x > 0 when this > that
    Implicit
    This member is added by an implicit conversion from Value tomath.Ordered[Value] performed by method orderingToOrdered in scala.math.Ordered.This conversion will take place only if an implicit value of type math.Ordering[Value] is in scope.
    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:
    (value: math.Ordered[Value]).compare(that)
    Definition Classes
    Ordered
  7. def compareTo(that: Value): Int

    Result of comparing this with operand that.

    Result of comparing this with operand that.

    Implicit
    This member is added by an implicit conversion from Value tomath.Ordered[Value] performed by method orderingToOrdered in scala.math.Ordered.This conversion will take place only if an implicit value of type math.Ordering[Value] is in scope.
    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:
    (value: math.Ordered[Value]).compareTo(that)
    Definition Classes
    Ordered → Comparable

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 Value toStringFormat[Value] 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): (Value, B)
    Implicit
    This member is added by an implicit conversion from Value toArrowAssoc[Value] 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 math.Ordered[Value]

Inherited from Comparable[Value]

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion orderingToOrdered fromValue to math.Ordered[Value]

Inherited by implicit conversion any2stringadd fromValue to any2stringadd[Value]

Inherited by implicit conversion StringFormat fromValue to StringFormat[Value]

Inherited by implicit conversion Ensuring fromValue to Ensuring[Value]

Inherited by implicit conversion ArrowAssoc fromValue to ArrowAssoc[Value]

Ungrouped