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HashLaws.scala
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HashLaws.scala
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/*
* Copyright (c) 2015 Typelevel
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package cats.kernel
package laws
import scala.util.hashing._
trait HashLaws[A] extends EqLaws[A] {
implicit override def E: Hash[A]
def hashCompatibility(x: A, y: A): IsEq[Boolean] =
(!E.eqv(x, y) || (Hash.hash(x) == Hash.hash(y))) <-> true
@deprecated("This law is no longer enforced", "2.9.0")
def sameAsUniversalHash(x: A, y: A): IsEq[Boolean] =
((E.hash(x) == x.hashCode) && (Hash.fromUniversalHashCode[A].hash(x) == x.hashCode()) &&
(E.eqv(x, y) == Hash.fromUniversalHashCode[A].eqv(x, y))) <-> true
@deprecated("This law is no longer enforced", "2.9.0")
def sameAsScalaHashing(x: A, y: A, scalaHashing: Hashing[A]): IsEq[Boolean] =
((E.hash(x) == Hash.fromHashing(scalaHashing).hash(x)) &&
(E.eqv(x, y) == Hash.fromHashing(scalaHashing).eqv(x, y))) <-> true
}
object HashLaws {
def apply[A](implicit ev: Hash[A]): HashLaws[A] =
new HashLaws[A] { def E: Hash[A] = ev }
}