zio.test.poly.GenFractionalPoly.scala Maven / Gradle / Ivy
/*
* Copyright 2020-2022 John A. De Goes and the ZIO Contributors
*
* 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 zio.test.poly
import zio.stacktracer.TracingImplicits.disableAutoTrace
import zio.test.{Gen, Sized}
import zio.Trace
/**
* `GenFractionalPoly` provides evidence that instances of `Gen[T]` and
* `Fractional[T]` exist for some concrete but unknown type `T`.
*/
trait GenFractionalPoly extends GenNumericPoly {
override val numT: Fractional[T]
}
object GenFractionalPoly {
/**
* Constructs an instance of `GenFractionalPoly` using the specified `Gen` and
* `Fractional` instances, existentially hiding the underlying type.
*/
def apply[A](gen: Gen[Sized, A], num: Fractional[A]): GenFractionalPoly =
new GenFractionalPoly {
type T = A
val genT = gen
val numT = num
}
/**
* Provides evidence that instances of `Gen` and `Fractional` exist for
* doubles.
*/
def double(implicit trace: Trace): GenFractionalPoly =
GenFractionalPoly(Gen.double, Numeric.DoubleIsFractional)
/**
* Provides evidence that instances of `Gen` and `Fractional` exist for
* floats.
*/
def float(implicit trace: Trace): GenFractionalPoly =
GenFractionalPoly(Gen.float, Numeric.FloatIsFractional)
/**
* A generator of polymorphic values constrainted to have a `Fractional`
* instance.
*/
def genFractionalPoly(implicit trace: Trace): Gen[Any, GenFractionalPoly] =
Gen.elements(double, float)
}