-
Notifications
You must be signed in to change notification settings - Fork 61
/
AskLaws.scala
47 lines (39 loc) · 1.24 KB
/
AskLaws.scala
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
/*
* Copyright 2021 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 mtl
package laws
import cats.laws.IsEq
import cats.laws.IsEqArrow
import cats.syntax.apply._
import cats.syntax.functor._
trait AskLaws[F[_], E] {
implicit def askInstance: Ask[F, E]
implicit def applicative: Applicative[F] = askInstance.applicative
// external law:
def askAddsNoEffects[A](fa: F[A]): IsEq[F[A]] =
askInstance.ask *> fa <-> fa
// internal law:
def readerIsAskAndMap[A](f: E => A): IsEq[F[A]] =
askInstance.ask.map(f) <-> askInstance.reader(f)
}
object AskLaws {
def apply[F[_], E](implicit instance0: Ask[F, E]): AskLaws[F, E] = {
new AskLaws[F, E] {
override val askInstance = instance0
}
}
}