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AsyncLaws.scala
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AsyncLaws.scala
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/*
* Copyright 2017 Typelevel
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cats
package effect
package laws
import cats.implicits._
import cats.laws._
trait AsyncLaws[F[_]] extends SyncLaws[F] {
implicit def F: Async[F]
def asyncRightIsPure[A](a: A) =
F.async[A](_(Right(a))) <-> F.pure(a)
def asyncLeftIsRaiseError[A](e: Throwable) =
F.async[A](_(Left(e))) <-> F.raiseError(e)
def repeatedAsyncEvaluationNotMemoized[A](a: A, f: A => A) = {
var cur = a
val change: F[Unit] = F async { cb =>
cur = f(cur)
cb(Right(()))
}
val read: F[A] = F.async(_(Right(cur)))
change >> change >> read <-> F.pure(f(f(a)))
}
}
object AsyncLaws {
def apply[F[_]](implicit F0: Async[F]): AsyncLaws[F] = new AsyncLaws[F] {
val F = F0
}
}