Scala Standard Library2.12.6 < 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.collection.parallel.immutable` - Immutable, parallel data-structures such as `ParVector`, `ParRange`, `ParHashMap` or `ParHashSet`
    - `scala.collection.parallel.mutable` - Mutable, parallel data-structures such as `ParArray`, `ParHashMap`, `ParTrieMap` or `ParHashSet`
  - `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.swing` - A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)
  - `scala.util.parsing` - Parser combinators (scala-parser-combinators.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 math

  The package object `scala.math` contains methods for performing basic numeric operations such as elementary exponential, logarithmic, root and trigonometric functions.

  The package object `scala.math` contains methods for performing basic numeric operations such as elementary exponential, logarithmic, root and trigonometric functions.

  All methods forward to java.lang.Math unless otherwise noted.

  Definition Classes
    scala
  See also

    java.lang.Math

- BigDecimal
- BigInt
- Equiv
- Fractional
- Integral
- LowPriorityEquiv
- LowPriorityOrderingImplicits
- Numeric
- Ordered
- Ordering
- PartialOrdering
- PartiallyOrdered
- ScalaNumericAnyConversions
- ScalaNumericConversions

t

scala.math

# Fractional 

###
Companion object Fractional

#### trait Fractional[T] extends Numeric[T]

Source
  Fractional.scala
Since

  2.8

Linear Supertypes
Numeric[T], Ordering[T], PartialOrdering[T], Equiv[T], Serializable, java.io.Serializable, Comparator[T], AnyRef, Any
Known Subclasses
BigDecimalIsFractional, BigDecimalIsFractional, DoubleIsFractional, DoubleIsFractional, FloatIsFractional, FloatIsFractional
 
Ordering

1. Alphabetic
2. By Inheritance

Inherited

1. Fractional
2. Numeric
3. Ordering
4. PartialOrdering
5. Equiv
6. Serializable
7. Serializable
8. Comparator
9. AnyRef
10. Any

Implicitly

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

1. Hide All
2. Show All

Visibility

1. Public
2. All

### Type Members

1.  class FractionalOps extends Ops
2.  class Ops extends AnyRef
   Definition Classes
     Numeric

### Abstract Value Members

1.  abstract def compare(x: T, y: T): Int

   Returns an integer whose sign communicates how x compares to y.

   Returns an integer whose sign communicates how x compares to y.

   The result sign has the following meaning:

   - negative if x < y
   - positive if x > y
   - zero otherwise (if x == y)
   Definition Classes
     Ordering → Comparator
2.  abstract def div(x: T, y: T): T
3.  abstract def fromInt(x: Int): T
   Definition Classes
     Numeric
4.  abstract def minus(x: T, y: T): T
   Definition Classes
     Numeric
5.  abstract def negate(x: T): T
   Definition Classes
     Numeric
6.  abstract def plus(x: T, y: T): T
   Definition Classes
     Numeric
7.  abstract def times(x: T, y: T): T
   Definition Classes
     Numeric
8.  abstract def toDouble(x: T): Double
   Definition Classes
     Numeric
9.  abstract def toFloat(x: T): Float
   Definition Classes
     Numeric
10.  abstract def toInt(x: T): Int
    Definition Classes
      Numeric
11.  abstract def toLong(x: T): Long
    Definition Classes
      Numeric

### 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 Fractional[T] to any2stringadd[Fractional[T]] performed by method any2stringadd in scala.Predef.
   Definition Classes
     any2stringadd
4.  def ->[B](y: B): (Fractional[T], B)
   Implicit
     This member is added by an implicit conversion from Fractional[T] to ArrowAssoc[Fractional[T]] 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 abs(x: T): T
   Definition Classes
     Numeric
7.  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`.

8.  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
     @native() @throws( ... )
   Note

     not specified by SLS as a member of AnyRef

9.  def ensuring(cond: (Fractional[T]) ⇒ Boolean, msg: ⇒ Any): Fractional[T]
   Implicit
     This member is added by an implicit conversion from Fractional[T] to Ensuring[Fractional[T]] performed by method Ensuring in scala.Predef.
   Definition Classes
     Ensuring
10.  def ensuring(cond: (Fractional[T]) ⇒ Boolean): Fractional[T]
    Implicit
      This member is added by an implicit conversion from Fractional[T] to Ensuring[Fractional[T]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
11.  def ensuring(cond: Boolean, msg: ⇒ Any): Fractional[T]
    Implicit
      This member is added by an implicit conversion from Fractional[T] to Ensuring[Fractional[T]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
12.  def ensuring(cond: Boolean): Fractional[T]
    Implicit
      This member is added by an implicit conversion from Fractional[T] to Ensuring[Fractional[T]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
13.  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
14.  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
15.  def equiv(x: T, y: T): Boolean

    Return true if `x` == `y` in the ordering.

    Return true if `x` == `y` in the ordering.

    Definition Classes
      Ordering → PartialOrdering → Equiv
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[java.lang]
    Definition Classes
      AnyRef
    Annotations
      @throws( classOf[java.lang.Throwable] )
    Note

      not specified by SLS as a member of AnyRef

17.  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 Fractional[T] to StringFormat[Fractional[T]] performed by method StringFormat in scala.Predef.
    Definition Classes
      StringFormat
    Annotations
      @inline()
18.  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
    Annotations
      @native()
19.  def gt(x: T, y: T): Boolean

    Return true if `x` > `y` in the ordering.

    Return true if `x` > `y` in the ordering.

    Definition Classes
      Ordering → PartialOrdering
20.  def gteq(x: T, y: T): Boolean

    Return true if `x` >= `y` in the ordering.

    Return true if `x` >= `y` in the ordering.

    Definition Classes
      Ordering → PartialOrdering
21.  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
    Annotations
      @native()
22.  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
23.  def lt(x: T, y: T): Boolean

    Return true if `x` < `y` in the ordering.

    Return true if `x` < `y` in the ordering.

    Definition Classes
      Ordering → PartialOrdering
24.  def lteq(x: T, y: T): Boolean

    Return true if `x` <= `y` in the ordering.

    Return true if `x` <= `y` in the ordering.

    Definition Classes
      Ordering → PartialOrdering
25.  def max(x: T, y: T): T

    Return `x` if `x` >= `y`, otherwise `y`.

    Return `x` if `x` >= `y`, otherwise `y`.

    Definition Classes
      Ordering
26.  def min(x: T, y: T): T

    Return `x` if `x` <= `y`, otherwise `y`.

    Return `x` if `x` <= `y`, otherwise `y`.

    Definition Classes
      Ordering
27.  implicit def mkNumericOps(lhs: T): FractionalOps
    Definition Classes
      Fractional → Numeric
28.  implicit def mkOrderingOps(lhs: T): Fractional.Ops

    This implicit method augments `T` with the comparison operators defined in `scala.math.Ordering.Ops`.

    This implicit method augments `T` with the comparison operators defined in `scala.math.Ordering.Ops`.

    Definition Classes
      Ordering
29.  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
30.  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

31.  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

32.  def on[U](f: (U) ⇒ T): Ordering[U]

    Given f, a function from U into T, creates an Ordering[U] whose compare function is equivalent to:

    Given f, a function from U into T, creates an Ordering[U] whose compare function is equivalent to:

        def compare(x:U, y:U) = Ordering[T].compare(f(x), f(y))

    Definition Classes
      Ordering
33.  def one: T
    Definition Classes
      Numeric
34.  def reverse: Ordering[T]

    Return the opposite ordering of this one.

    Return the opposite ordering of this one.

    Definition Classes
      Ordering → PartialOrdering
35.  def reversed(): Comparator[T]
    Definition Classes
      Comparator
36.  def signum(x: T): Int
    Definition Classes
      Numeric
37.  final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
      AnyRef
38.  def thenComparing[U <: Comparable[_ >: U]](arg0: java.util.function.Function[_ >: T, _ <: U]): Comparator[T]
    Definition Classes
      Comparator
39.  def thenComparing[U](arg0: java.util.function.Function[_ >: T, _ <: U], arg1: Comparator[_ >: U]): Comparator[T]
    Definition Classes
      Comparator
40.  def thenComparing(arg0: Comparator[_ >: T]): Comparator[T]
    Definition Classes
      Comparator
41.  def thenComparingDouble(arg0: ToDoubleFunction[_ >: T]): Comparator[T]
    Definition Classes
      Comparator
42.  def thenComparingInt(arg0: ToIntFunction[_ >: T]): Comparator[T]
    Definition Classes
      Comparator
43.  def thenComparingLong(arg0: ToLongFunction[_ >: T]): Comparator[T]
    Definition Classes
      Comparator
44.  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
45.  def tryCompare(x: T, y: T): Some[Int]

    Returns whether a comparison between `x` and `y` is defined, and if so the result of `compare(x, y)`.

    Returns whether a comparison between `x` and `y` is defined, and if so the result of `compare(x, y)`.

    Definition Classes
      Ordering → PartialOrdering
46.  final def wait(): Unit
    Definition Classes
      AnyRef
    Annotations
      @throws( ... )
47.  final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
      AnyRef
    Annotations
      @throws( ... )
48.  final def wait(arg0: Long): Unit
    Definition Classes
      AnyRef
    Annotations
      @native() @throws( ... )
49.  def zero: T
    Definition Classes
      Numeric
50.  def →[B](y: B): (Fractional[T], B)
    Implicit
      This member is added by an implicit conversion from Fractional[T] to ArrowAssoc[Fractional[T]] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
      ArrowAssoc

### Inherited from Numeric[T]

### Inherited from Ordering[T]

### Inherited from PartialOrdering[T]

### Inherited from Equiv[T]

### Inherited from Serializable

### Inherited from java.io.Serializable

### Inherited from Comparator[T]

### Inherited from AnyRef

### Inherited from Any

### Inherited by implicit conversion any2stringadd from Fractional[T] to any2stringadd[Fractional[T]]

### Inherited by implicit conversion StringFormat from Fractional[T] to StringFormat[Fractional[T]]

### Inherited by implicit conversion Ensuring from Fractional[T] to Ensuring[Fractional[T]]

### Inherited by implicit conversion ArrowAssoc from Fractional[T] to ArrowAssoc[Fractional[T]]

### Ungrouped