scala.math.PartiallyOrdered.scala Maven / Gradle / Ivy
/*
* Scala (https://www.scala-lang.org)
*
* Copyright EPFL and Lightbend, Inc.
*
* Licensed under Apache License 2.0
* (http://www.apache.org/licenses/LICENSE-2.0).
*
* See the NOTICE file distributed with this work for
* additional information regarding copyright ownership.
*/
package scala
package math
/** A class for partially ordered data.
*/
trait PartiallyOrdered[+A] extends Any {
type AsPartiallyOrdered[B] = B => PartiallyOrdered[B]
/** Result of comparing `'''this'''` with operand `that`.
* Returns `None` if operands are not comparable.
* If operands are comparable, returns `Some(x)` where
* - `x < 0` iff `'''this''' < that`
* - `x == 0` iff `'''this''' == that`
* - `x > 0` iff `'''this''' > that`
*/
def tryCompareTo [B >: A: AsPartiallyOrdered](that: B): Option[Int]
def < [B >: A: AsPartiallyOrdered](that: B): Boolean =
(this tryCompareTo that) match {
case Some(x) if x < 0 => true
case _ => false
}
def > [B >: A: AsPartiallyOrdered](that: B): Boolean =
(this tryCompareTo that) match {
case Some(x) if x > 0 => true
case _ => false
}
def <= [B >: A: AsPartiallyOrdered](that: B): Boolean =
(this tryCompareTo that) match {
case Some(x) if x <= 0 => true
case _ => false
}
def >= [B >: A: AsPartiallyOrdered](that: B): Boolean =
(this tryCompareTo that) match {
case Some(x) if x >= 0 => true
case _ => false
}
}