trait PartialOrdering in scala.math

scala.math

trait PartialOrdering

[source: scala/math/PartialOrdering.scala]

trait PartialOrdering[T]: extends Equiv[T] with AnyRef

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

A partial ordering is a binary relation on a type T that is also an equivalence relation on values of type T. This relation is exposed as the lteq method of the PartialOrdering trait. This relation must be:

reflexive: lteq(x, x) == true, for any x of type T.
anti-symmetric: lteq(x, y) == true and lteq(y, x) == true then equiv(x, y), for any x and y of type T.
transitive: if lteq(x, y) == true and lteq(y, z) == true then lteq(x, z) == true, for any x, y, and z of type T.

Author: Geoffrey Washburn
Version: 1.0, 2008-04-0-3
Since: 2.7

Direct Known Subclasses:: Ordering

Method Summary
`def`	equiv (x : T, y : T) : Boolean Returns `true` iff `x` is equivalent to `y` in the ordering.
`def`	gt (x : T, y : T) : Boolean Returns `true` iff `y` comes before `x` in the ordering and is not the same as `x`.
`def`	gteq (x : T, y : T) : Boolean Returns `true` iff `y` comes before `x` in the ordering.
`def`	lt (x : T, y : T) : Boolean Returns `true` iff `x` comes before `y` in the ordering and is not the same as `y`.
`abstract def`	lteq (x : T, y : T) : Boolean Returns `true` iff `x` comes before `y` in the ordering.
`def`	reverse : PartialOrdering[T]
`abstract def`	tryCompare (x : T, y : T) : Option[Int] Result of comparing `x` with operand `y`. Returns `None` if operands are not comparable. If operands are comparable, returns `Some(r)` where `r < 0` iff `x < y` `r == 0` iff `x == y` `r > 0` iff `x > y`

Methods inherited from AnyRef
getClass, hashCode, equals, clone, toString, notify, notifyAll, wait, wait, wait, finalize, ==, !=, eq, ne, synchronized

Methods inherited from Any
==, !=, isInstanceOf, asInstanceOf

Method Details

abstract def tryCompare(x : T, y : T) : Option[Int]

Result of comparing x with operand y. Returns None if operands are not comparable. If operands are comparable, returns Some(r) where r < 0 iff x < y r == 0 iff x == y r > 0 iff x > y

abstract def lteq(x : T, y : T) : Boolean

Returns true iff x comes before y in the ordering.

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

Returns true iff y comes before x in the ordering.

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

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

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

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

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

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

Overrides: Equiv.equiv

def reverse : PartialOrdering[T]

	Scala Library

	Scala Library