smithy4s.capability.instances.either.scala Maven / Gradle / Ivy
/*
* Copyright 2021-2024 Disney Streaming
*
* Licensed under the Tomorrow Open Source Technology License, Version 1.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://disneystreaming.github.io/TOST-1.0.txt
*
* 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 smithy4s.capability
package instances
object either {
implicit def eitherZipper[E]: Zipper[Either[E, *]] =
new Zipper[Either[E, *]] {
def pure[A](a: A): Either[E, A] = Right(a)
override def zipMap[A, B, C](fa: Either[E, A], fb: Either[E, B])(
f: (A, B) => C
): Either[E, C] = (fa, fb) match {
case (l @ Left(_), _) => l.asInstanceOf[Either[E, C]]
case (_, r @ Left(_)) => r.asInstanceOf[Either[E, C]]
case (Right(a), Right(b)) => Right(f(a, b))
}
override def zipMapAll[A](
seq: IndexedSeq[Either[E, Any]]
)(f: IndexedSeq[Any] => A): Either[E, A] = {
val builder = IndexedSeq.newBuilder[Any]
var i = 0
var error: Left[E, Any] = null
while (error == null && i < seq.size) {
seq(i) match {
case l @ Left(_) => error = l.asInstanceOf[Left[E, Any]]
case Right(r) => builder += r
}
i += 1
}
if (error != null) error.asInstanceOf[Left[E, A]]
else Right(f(builder.result()))
}
}
}