scala.math

Ordering

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

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 representing the latter.

A total 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:

known subclasses: Numeric, StringOrdering, BigDecimalOrdering, BigIntOrdering, DoubleOrdering, FloatOrdering, LongOrdering, IntOrdering, ShortOrdering, CharOrdering, ByteOrdering, BooleanOrdering, UnitOrdering
Go to: companion

Inherits

  1. PartialOrdering
  2. Equiv
  3. Comparator
  4. AnyRef
  5. Any

Type Members

  1. class Ops extends AnyRef

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
    Go to: companion
  2. def equals(arg0: Any): Boolean

    This method is used to compare the receiver object (this) with the argument object (arg0) for equivalence

    This method is used to compare the receiver object (this) with the argument object (arg0) for equivalence.

    The default implementations of this method is an equivalence relation:

    • It is reflexive: for any instance x of type Any, x.equals(x) should return true.
    • It is symmetric: for any instances x and y of type Any, x.equals(y) should return true if and only if y.equals(x) returns true.
    • It is transitive: for any instances x, y, and z of type AnyRef if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.

    If you override this method, you should verify that your implementation remains an equivalence relation. Additionally, when overriding this method it is often necessary to override hashCode to ensure that objects that are "equal" (o1.equals(o2) returns true) hash to the same Int (o1.hashCode.equals(o2.hashCode)).

    arg0

    the object to compare against this object for equality.

    returns

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

    definition classes: AnyRef ⇐ Any
    Go to: companion
  3. def equiv(x: T, y: T): Boolean

    Returns true iff x is equivalent to y in the ordering

    Returns true iff x is equivalent to y in the ordering.

    Go to: companion
  4. def gt(x: T, y: T): Boolean

    Returns true iff y comes before x in the ordering and is not the same as x

    Returns true iff y comes before x in the ordering and is not the same as x.

    Go to: companion
  5. def gteq(x: T, y: T): Boolean

    Returns true iff y comes before x in the ordering

    Returns true iff y comes before x in the ordering.

    Go to: companion
  6. def hashCode(): Int

    Returns a hash code value for the object

    Returns a hash code value for the object.

    The default hashing algorithm is platform dependent.

    Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)) yet not be equal (o1.equals(o2) returns false). A degenerate implementation could always return 0. However, it is required that if two objects are equal (o1.equals(o2) returns true) that they have identical hash codes (o1.hashCode.equals(o2.hashCode)). Therefore, when overriding this method, be sure to verify that the behavior is consistent with the equals method.

    definition classes: AnyRef ⇐ Any
    Go to: companion
  7. def lt(x: T, y: T): Boolean

    Returns true iff x comes before y in the ordering and is not the same as y

    Returns true iff x comes before y in the ordering and is not the same as y.

    Go to: companion
  8. def lteq(x: T, y: T): Boolean

    Returns true iff x comes before y in the ordering

    Returns true iff x comes before y in the ordering.

    Go to: companion
  9. def max(x: T, y: T): T

    Returns the argument which comes later in the ordering

    Returns the argument which comes later in the ordering.

    Go to: companion
  10. def min(x: T, y: T): T

    Returns the argument which comes earlier in the ordering

    Returns the argument which comes earlier in the ordering.

    Go to: companion
  11. def mkOrderingOps(lhs: T): Ops

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

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

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

    Go to: companion
  13. def reverse: Ordering[T]

  14. def toString(): String

    Returns a string representation of the object

    Returns a string representation of the object.

    The default representation is platform dependent.

    definition classes: AnyRef ⇐ Any
    Go to: companion
  15. 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.

    Go to: companion