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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.fix
import arrow.core.identity
import arrow.effects.ForIO
import arrow.effects.IO
import arrow.effects.fix
import arrow.effects.instances.io.monad.monad
import arrow.instances.option.monad.monad
import arrow.syntax.collections.firstOption
import arrow.typeclasses.MonadContinuation
import arrow.typeclasses.binding
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()
}
object IOUtils {
fun <A> binding(c: suspend MonadContinuation<ForIO, *>.() -> A)
: IO<A> = IO.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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