-
Notifications
You must be signed in to change notification settings - Fork 509
/
SyncLaws.scala
80 lines (64 loc) · 1.87 KB
/
SyncLaws.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
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
/*
* Copyright 2020-2022 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.effect
package laws
import cats.effect.kernel.Sync
import cats.syntax.all._
trait SyncLaws[F[_]]
extends MonadCancelLaws[F, Throwable]
with ClockLaws[F]
with UniqueLaws[F] {
implicit val F: Sync[F]
def suspendValueIsPure[A](a: A, hint: Sync.Type) =
F.suspend(hint)(a) <-> F.pure(a)
def suspendThrowIsRaiseError[A](e: Throwable, hint: Sync.Type) =
F.suspend[A](hint)(throw e) <-> F.raiseError(e)
def unsequencedSuspendIsNoop[A](a: A, f: A => A, hint: Sync.Type) = {
val isWith = F delay {
var cur = a
val _ = F.suspend(hint) { cur = f(cur) }
F.delay(cur)
}
val isWithout = F delay {
var cur = a
cur = a // no-op to confuse the compiler
F.delay(cur)
}
isWith.flatten <-> isWithout.flatten
}
def repeatedSuspendNotMemoized[A](a: A, f: A => A, hint: Sync.Type) = {
val isWith = F delay {
var cur = a
val changeF = F.suspend(hint) {
cur = f(cur)
cur
}
changeF >> changeF
}
val isWithout = F delay {
var cur = a
F.suspend(hint) {
cur = f(f(cur))
cur
}
}
isWith.flatten <-> isWithout.flatten
}
}
object SyncLaws {
def apply[F[_]](implicit F0: Sync[F]): SyncLaws[F] =
new SyncLaws[F] { val F = F0 }
}