scala.math

Ordering

trait Ordering [T] extends Comparator[T] with PartialOrdering[T] with Serializable

A trait for representing total orderings. It is important to distinguish between a type that has a total order and a representation of total ordering on some type. This trait is for the latter.

A ordering is a binary relation on a type T that is also an equivalence relation and partial ordering on values of type T. This relation is exposed as the compare method of the Ordering trait.

This relation must be:

      reflexive:  x == x
  antisymmetric:  if x <= y && y <= x, then x == y
     transitive:  if x <= y && y <= z, then x <= z
Self Type
Ordering[T]
Annotations
@implicitNotFound( msg = ... )
Source
Ordering.scala
Version

0.9.5, 2008-04-15

Since

2.7

Linear Supertypes
Serializable, Serializable, PartialOrdering[T], Equiv[T], Comparator[T], AnyRef, Any
Known Subclasses
BigDecimal, BigDecimalAsIfIntegral, BigDecimalAsIfIntegral, BigDecimalIsConflicted, BigDecimalIsFractional, BigDecimalIsFractional, BigDecimalOrdering, BigInt, BigIntIsIntegral, BigIntIsIntegral, BigIntOrdering, Boolean, BooleanOrdering, Byte, ByteIsIntegral, ByteIsIntegral, ByteOrdering, Char, CharIsIntegral, CharIsIntegral, CharOrdering, Double, DoubleAsIfIntegral, DoubleAsIfIntegral, DoubleIsConflicted, DoubleIsFractional, DoubleIsFractional, DoubleOrdering, Float, FloatAsIfIntegral, FloatAsIfIntegral, FloatIsConflicted, FloatIsFractional, FloatIsFractional, FloatOrdering, Fractional, Int, IntIsIntegral, IntIsIntegral, IntOrdering, Integral, Long, LongIsIntegral, LongIsIntegral, LongOrdering, Numeric, OptionOrdering, Short, ShortIsIntegral, ShortIsIntegral, ShortOrdering, String, StringOrdering, Unit, UnitOrdering
Ordering
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Inherited
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  1. Ordering
  2. Serializable
  3. Serializable
  4. PartialOrdering
  5. Equiv
  6. Comparator
  7. AnyRef
  8. Any
Visibility
  1. Public
  2. All

Type Members

  1. class Ops extends AnyRef

Abstract Value Members

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

    Returns a negative integer iff x comes before y in the ordering, returns 0 iff x is the same in the ordering as y, and returns a positive number iff x comes after y in the ordering.

    Returns a negative integer iff x comes before y in the ordering, returns 0 iff x is the same in the ordering as y, and returns a positive number iff x comes after y in the ordering.

    Attributes
    abstract
    Definition Classes
    Ordering → Comparator

Concrete Value Members

  1. def != (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef

  2. def != (arg0: Any): Boolean

    Test two objects for inequality.

    Test two objects for inequality.

    returns

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

    Attributes
    final
    Definition Classes
    Any

  3. def ## (): Int

    Equivalent to x.hashCode except for boxed numeric types.

    Equivalent to x.hashCode except for boxed numeric types. 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.

    returns

    a hash value consistent with ==

    Attributes
    final
    Definition Classes
    AnyRef → Any

  4. def == (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef

  5. def == (arg0: Any): Boolean

    Test two objects for equality.

    Test two objects for equality.

    returns

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

    Attributes
    final
    Definition Classes
    Any

  6. 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.

    Attributes
    final
    Definition Classes
    Any

  7. 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()

  8. def eq (arg0: AnyRef): Boolean

    Tests whether the argument (arg0) is a reference to the receiver object (this).

    Tests whether the argument (arg0) 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.

    Attributes
    final
    Definition Classes
    AnyRef

  9. def equals (arg0: Any): Boolean

    The equality method for reference types.

    The equality method for reference types. See equals in Any.

    returns

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

    Definition Classes
    AnyRef → Any

  10. def equiv (x: T, y: T): Boolean

    returns

    true iff x is equivalent to y in the ordering.

    Definition Classes
    Ordering → PartialOrdering → Equiv

  11. 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()

  12. def getClass (): java.lang.Class[_]

    A representation that corresponds to the dynamic class of the receiver object.

    A representation that corresponds to the dynamic class of the receiver object.

    The nature of the representation is platform dependent.

    returns

    a representation that corresponds to the dynamic class of the receiver object.

    Attributes
    final
    Definition Classes
    AnyRef → Any

  13. def gt (x: T, y: T): Boolean

    returns

    true iff y comes before x in the ordering, and is not equal to x.

    Definition Classes
    Ordering → PartialOrdering

  14. def gteq (x: T, y: T): Boolean

    returns

    true iff x comes after y in the ordering, or is equal to y.

    Definition Classes
    Ordering → PartialOrdering

  15. def hashCode (): Int

    The hashCode method for reference types.

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

    returns

    the hash code value for this object.

    Definition Classes
    AnyRef → Any

  16. 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.

    Attributes
    final
    Definition Classes
    Any

  17. def lt (x: T, y: T): Boolean

    returns

    true iff x comes before y in the ordering, and is not equal to y.

    Definition Classes
    Ordering → PartialOrdering

  18. def lteq (x: T, y: T): Boolean

    returns

    true iff x comes before y in the ordering, or is equal to y.

    Definition Classes
    Ordering → PartialOrdering

  19. def max (x: T, y: T): T

    Returns the argument which comes later in the ordering.

  20. def min (x: T, y: T): T

    Returns the argument which comes earlier in the ordering.

  21. implicit def mkOrderingOps (lhs: T): Ops

    Attributes
    implicit

  22. 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.

    Attributes
    final
    Definition Classes
    AnyRef

  23. 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.

    Attributes
    final
    Definition Classes
    AnyRef

  24. 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.

    Attributes
    final
    Definition Classes
    AnyRef

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

    Given a function U => T, creates Ordering[U].

  26. def reverse : Ordering[T]

    Definition Classes
    Ordering → PartialOrdering

  27. def synchronized [T0] (arg0: ⇒ T0): T0

    Attributes
    final
    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. def tryCompare (x: T, y: T): Some[Int]

    An Ordering is defined at all x and y.

    An Ordering is defined at all x and y.

    Definition Classes
    Ordering → PartialOrdering

  30. def wait (): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()

  31. def wait (arg0: Long, arg1: Int): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()

  32. def wait (arg0: Long): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()