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/*
* ============LICENSE_START=======================================================
* dcaegen2-collectors-veshv
* ================================================================================
* Copyright (C) 2018 NOKIA
* ================================================================================
* 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.
* ============LICENSE_END=========================================================
*/
package org.onap.dcae.collectors.veshv.utils.arrow
import arrow.core.Either
import arrow.core.ForOption
import arrow.core.Option
import arrow.core.Try
import arrow.core.extensions.option.monad.monad
import arrow.core.fix
import arrow.core.identity
import arrow.syntax.collections.firstOption
import arrow.typeclasses.MonadContinuation
import reactor.core.publisher.Flux
import reactor.core.publisher.Mono
import java.util.concurrent.atomic.AtomicReference
/**
* @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
* @since July 2018
*/
object OptionUtils {
fun <A> binding(c: suspend MonadContinuation<ForOption, *>.() -> A)
: Option<A> = Option.monad().binding(c).fix()
}
fun <A> Either<A, A>.flatten() = fold(::identity, ::identity)
fun <B> Either<Throwable, B>.rightOrThrow() = fold({ throw it }, ::identity)
fun <A, B> Either<A, B>.rightOrThrow(mapper: (A) -> Throwable) = fold({ throw mapper(it) }, ::identity)
fun <A : Exception, B> Flux<Either<A, B>>.throwOnLeft(): Flux<B> = map { it.rightOrThrow() }
fun <A, B> Flux<Either<A, B>>.throwOnLeft(f: (A) -> Exception): Flux<B> = map { it.rightOrThrow(f) }
fun <A, B> Mono<Either<A, B>>.throwOnLeft(f: (A) -> Exception): Mono<B> = map { it.rightOrThrow(f) }
fun <A> AtomicReference<A>.getOption() = Option.fromNullable(get())
fun <A> Option.Companion.fromNullablesChain(firstValue: A?, vararg nextValues: () -> A?): Option<A> =
if (firstValue != null)
Option.just(firstValue)
else nextValues.asSequence()
.map { it() }
.filter { it != null }
.firstOption()
fun <A, B> Either<A, B>.doOnLeft(action: () -> Unit): Either<A, B> = apply { if (isLeft()) action() }
fun <A> Option<A>.doOnEmpty(action: () -> Unit): Option<A> = apply { if (isEmpty()) action() }
fun <A> Try<A>.doOnFailure(action: (Throwable) -> Unit): Try<A> = apply {
if (this is Try.Failure) {
action(exception)
}
}
fun <A, B> A.mapBinding(c: suspend MonadContinuation<ForOption, *>.(A) -> B)
: Option<B> = let { OptionUtils.binding { c(it) } }
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