Ordering

scala.math.Ordering$

See theOrdering companion trait

object Ordering extends LowPriorityOrderingImplicits

This is the companion object for the scala.math.Ordering trait.

It contains many implicit orderings as well as well as methods to construct new orderings.

Attributes

Companion: trait
Source: Ordering.scala
Graph
Supertypes: trait LowPriorityOrderingImplicits

class Object

trait Matchable

class Any
Self type: Ordering.type

Members list

Type members

Classlikes

Attributes

Source: Ordering.scala
Supertypes: trait BigDecimalOrdering

trait Ordering[BigDecimal]

trait PartialOrdering[BigDecimal]

trait Equiv[BigDecimal]

trait Serializable

trait Comparator[BigDecimal]

class Object

trait Matchable

class Any
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Self type: BigDecimal.type

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[BigDecimal]

trait PartialOrdering[BigDecimal]

trait Equiv[BigDecimal]

trait Serializable

trait Comparator[BigDecimal]

class Object

trait Matchable

class Any
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Known subtypes: object BigDecimalAsIfIntegral.type

object BigDecimalIsFractional.type

object BigDecimal.type

Attributes

Source: Ordering.scala
Supertypes: trait BigIntOrdering

trait Ordering[BigInt]

trait PartialOrdering[BigInt]

trait Equiv[BigInt]

trait Serializable

trait Comparator[BigInt]

class Object

trait Matchable

class Any
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Self type: BigInt.type

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[BigInt]

trait PartialOrdering[BigInt]

trait Equiv[BigInt]

trait Serializable

trait Comparator[BigInt]

class Object

trait Matchable

class Any
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Known subtypes: object BigIntIsIntegral.type

object BigInt.type

Attributes

Source: Ordering.scala
Supertypes: trait BooleanOrdering

trait Ordering[Boolean]

trait PartialOrdering[Boolean]

trait Equiv[Boolean]

trait Serializable

trait Comparator[Boolean]

class Object

trait Matchable

class Any
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Self type: Boolean.type

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[Boolean]

trait PartialOrdering[Boolean]

trait Equiv[Boolean]

trait Serializable

trait Comparator[Boolean]

class Object

trait Matchable

class Any
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Known subtypes: object Boolean.type

Attributes

Source: Ordering.scala
Supertypes: trait ByteOrdering

trait Ordering[Byte]

trait PartialOrdering[Byte]

trait Equiv[Byte]

trait Serializable

trait Comparator[Byte]

class Object

trait Matchable

class Any
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Self type: Byte.type

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[Byte]

trait PartialOrdering[Byte]

trait Equiv[Byte]

trait Serializable

trait Comparator[Byte]

class Object

trait Matchable

class Any
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Known subtypes: object ByteIsIntegral.type

object Byte.type

An ordering which caches the value of its reverse.

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[T]

trait PartialOrdering[T]

trait Equiv[T]

trait Serializable

trait Comparator[T]

class Object

trait Matchable

class Any
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Known subtypes: object Int.type

Attributes

Source: Ordering.scala
Supertypes: trait CharOrdering

trait Ordering[Char]

trait PartialOrdering[Char]

trait Equiv[Char]

trait Serializable

trait Comparator[Char]

class Object

trait Matchable

class Any
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Self type: Char.type

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[Char]

trait PartialOrdering[Char]

trait Equiv[Char]

trait Serializable

trait Comparator[Char]

class Object

trait Matchable

class Any
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Known subtypes: object CharIsIntegral.type

object Char.type

Attributes

Source: Ordering.scala
Supertypes: trait TotalOrdering

trait Ordering[Double]

trait PartialOrdering[Double]

trait Equiv[Double]

trait Serializable

trait Comparator[Double]

class Object

trait Matchable

class Any
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Self type: DeprecatedDoubleOrdering.type

Attributes

Source: Ordering.scala
Supertypes: trait TotalOrdering

trait Ordering[Float]

trait PartialOrdering[Float]

trait Equiv[Float]

trait Serializable

trait Comparator[Float]

class Object

trait Matchable

class Any
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Self type: DeprecatedFloatOrdering.type

Orderings for Doubles.

The behavior of the comparison operations provided by the default (implicit) ordering on Double changed in 2.10.0 and 2.13.0. Prior to Scala 2.10.0, the Ordering instance used semantics consistent with java.lang.Double.compare.

Scala 2.10.0 changed the implementation of lt, equiv, min, etc., to be IEEE 754 compliant, while keeping the compare method NOT compliant, creating an internally inconsistent instance. IEEE 754 specifies that 0.0 == -0.0. In addition, it requires all comparisons with Double.NaN return false thus 0.0 < Double.NaN, 0.0 > Double.NaN, and Double.NaN == Double.NaN all yield false, analogous None in flatMap.

Recognizing the limitation of the IEEE 754 semantics in terms of ordering, Scala 2.13.0 created two instances: Ordering.Double.IeeeOrdering, which retains the IEEE 754 semantics from Scala 2.12.x, and Ordering.Double.TotalOrdering, which brings back the java.lang.Double.compare semantics for all operations. The default extends TotalOrdering.

List(0.0, 1.0, 0.0 / 0.0, -1.0 / 0.0).sorted      // List(-Infinity, 0.0, 1.0, NaN)
List(0.0, 1.0, 0.0 / 0.0, -1.0 / 0.0).min         // -Infinity
implicitly[Ordering[Double]].lt(0.0, 0.0 / 0.0)   // true
{
  import Ordering.Double.IeeeOrdering
  List(0.0, 1.0, 0.0 / 0.0, -1.0 / 0.0).sorted    // List(-Infinity, 0.0, 1.0, NaN)
  List(0.0, 1.0, 0.0 / 0.0, -1.0 / 0.0).min       // NaN
  implicitly[Ordering[Double]].lt(0.0, 0.0 / 0.0) // false
}

Attributes

Source: Ordering.scala
Supertypes: class Object

trait Matchable

class Any
Self type: Double.type

Attributes

Source: Ordering.scala
Supertypes: class Object

trait Matchable

class Any
Known subtypes: object Implicits.type

Orderings for Floats.

The behavior of the comparison operations provided by the default (implicit) ordering on Float changed in 2.10.0 and 2.13.0. Prior to Scala 2.10.0, the Ordering instance used semantics consistent with java.lang.Float.compare.

Scala 2.10.0 changed the implementation of lt, equiv, min, etc., to be IEEE 754 compliant, while keeping the compare method NOT compliant, creating an internally inconsistent instance. IEEE 754 specifies that 0.0F == -0.0F. In addition, it requires all comparisons with Float.NaN return false thus 0.0F < Float.NaN, 0.0F > Float.NaN, and Float.NaN == Float.NaN all yield false, analogous None in flatMap.

Recognizing the limitation of the IEEE 754 semantics in terms of ordering, Scala 2.13.0 created two instances: Ordering.Float.IeeeOrdering, which retains the IEEE 754 semantics from Scala 2.12.x, and Ordering.Float.TotalOrdering, which brings back the java.lang.Float.compare semantics for all operations. The default extends TotalOrdering.

List(0.0F, 1.0F, 0.0F / 0.0F, -1.0F / 0.0F).sorted      // List(-Infinity, 0.0, 1.0, NaN)
List(0.0F, 1.0F, 0.0F / 0.0F, -1.0F / 0.0F).min         // -Infinity
implicitly[Ordering[Float]].lt(0.0F, 0.0F / 0.0F)       // true
{
  import Ordering.Float.IeeeOrdering
  List(0.0F, 1.0F, 0.0F / 0.0F, -1.0F / 0.0F).sorted    // List(-Infinity, 0.0, 1.0, NaN)
  List(0.0F, 1.0F, 0.0F / 0.0F, -1.0F / 0.0F).min       // NaN
  implicitly[Ordering[Float]].lt(0.0F, 0.0F / 0.0F)     // false
}

Attributes

Source: Ordering.scala
Supertypes: class Object

trait Matchable

class Any
Self type: Float.type

An object containing implicits which are not in the default scope.

Attributes

Source: Ordering.scala
Supertypes: trait ExtraImplicits

class Object

trait Matchable

class Any
Self type: Implicits.type

Attributes

Source: Ordering.scala
Supertypes: trait CachedReverse[Int]

trait IntOrdering

trait Ordering[Int]

trait PartialOrdering[Int]

trait Equiv[Int]

trait Serializable

trait Comparator[Int]

class Object

trait Matchable

class Any
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Self type: Int.type

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[Int]

trait PartialOrdering[Int]

trait Equiv[Int]

trait Serializable

trait Comparator[Int]

class Object

trait Matchable

class Any
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Known subtypes: object IntIsIntegral.type

object Int.type

Attributes

Source: Ordering.scala
Supertypes: trait LongOrdering

trait Ordering[Long]

trait PartialOrdering[Long]

trait Equiv[Long]

trait Serializable

trait Comparator[Long]

class Object

trait Matchable

class Any
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Self type: Long.type

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[Long]

trait PartialOrdering[Long]

trait Equiv[Long]

trait Serializable

trait Comparator[Long]

class Object

trait Matchable

class Any
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Known subtypes: object LongIsIntegral.type

object Long.type

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[Option[T]]

trait PartialOrdering[Option[T]]

trait Equiv[Option[T]]

trait Serializable

trait Comparator[Option[T]]

class Object

trait Matchable

class Any
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Attributes

Source: Ordering.scala
Supertypes: trait ShortOrdering

trait Ordering[Short]

trait PartialOrdering[Short]

trait Equiv[Short]

trait Serializable

trait Comparator[Short]

class Object

trait Matchable

class Any
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Self type: Short.type

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[Short]

trait PartialOrdering[Short]

trait Equiv[Short]

trait Serializable

trait Comparator[Short]

class Object

trait Matchable

class Any
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Known subtypes: object ShortIsIntegral.type

object Short.type

Attributes

Source: Ordering.scala
Supertypes: trait StringOrdering

trait Ordering[String]

trait PartialOrdering[String]

trait Equiv[String]

trait Serializable

trait Comparator[String]

class Object

trait Matchable

class Any
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Self type: String.type

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[String]

trait PartialOrdering[String]

trait Equiv[String]

trait Serializable

trait Comparator[String]

class Object

trait Matchable

class Any
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Known subtypes: object String.type

Attributes

Source: Ordering.scala
Supertypes: trait SymbolOrdering

trait Ordering[Symbol]

trait PartialOrdering[Symbol]

trait Equiv[Symbol]

trait Serializable

trait Comparator[Symbol]

class Object

trait Matchable

class Any
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Self type: Symbol.type

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[Symbol]

trait PartialOrdering[Symbol]

trait Equiv[Symbol]

trait Serializable

trait Comparator[Symbol]

class Object

trait Matchable

class Any
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Known subtypes: object Symbol.type

Attributes

Source: Ordering.scala
Supertypes: trait UnitOrdering

trait Ordering[Unit]

trait PartialOrdering[Unit]

trait Equiv[Unit]

trait Serializable

trait Comparator[Unit]

class Object

trait Matchable

class Any
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Self type: Unit.type

Attributes

Source: Ordering.scala
Supertypes: trait Ordering[Unit]

trait PartialOrdering[Unit]

trait Equiv[Unit]

trait Serializable

trait Comparator[Unit]

class Object

trait Matchable

class Any
Show all
Known subtypes: object Unit.type

Inherited types

Attributes

Inherited from:: LowPriorityOrderingImplicits
Source: Ordering.scala

Value members

Concrete methods

Attributes

Source: Ordering.scala

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

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

This function is an analogue to Ordering.on where the Ordering[S] parameter is passed implicitly.

Attributes

Source: Ordering.scala

Construct an Ordering[T] given a function lt.

Attributes

Source: Ordering.scala

Implicits

Attributes

Source: Ordering.scala

Attributes

Source: Ordering.scala

Attributes

Source: Ordering.scala

Attributes

Source: Ordering.scala

Attributes

Source: Ordering.scala

Attributes

Source: Ordering.scala

Attributes

Source: Ordering.scala

Attributes

Source: Ordering.scala

Attributes

Source: Ordering.scala

Deprecated implicits

Attributes

Deprecated: [Since version 2.13.0]
Iterables are not guaranteed to have a consistent order, so the Ordering returned by this method may not be stable or meaningful. If you are using a type with a consistent order (such as Seq), use its Ordering (found in the Implicits object) instead.
Source: Ordering.scala

Inherited implicits

Attributes

Inherited from:: LowPriorityOrderingImplicits
Source: Ordering.scala

This would conflict with all the nice implicit Orderings available, but thanks to the magic of prioritized implicits via subclassing we can make Ordered[A] => Ordering[A] only turn up if nothing else works. Since Ordered[A] extends Comparable[A] anyway, we can throw in some Java interop too.

Attributes

Inherited from:: LowPriorityOrderingImplicits
Source: Ordering.scala

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