2 * ============LICENSE_START=======================================================
3 * dcaegen2-collectors-veshv
4 * ================================================================================
5 * Copyright (C) 2018 NOKIA
6 * ================================================================================
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 * ============LICENSE_END=========================================================
20 package org.onap.dcae.collectors.veshv.utils.arrow
22 import arrow.core.Either
23 import arrow.core.Option
24 import arrow.core.identity
25 import arrow.syntax.collections.firstOption
26 import java.util.concurrent.atomic.AtomicReference
29 * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
33 fun <A> Either<A, A>.flatten() = fold(::identity, ::identity)
35 fun <B> Either<Throwable, B>.rightOrThrow() = fold({ throw it }, ::identity)
37 fun <A, B> Either<A, B>.rightOrThrow(mapper: (A) -> Throwable) = fold({ throw mapper(it) }, ::identity)
39 fun <A> AtomicReference<A>.getOption() = Option.fromNullable(get())
41 fun <A> Option.Companion.fromNullablesChain(firstValue: A?, vararg nextValues: () -> A?): Option<A> =
42 if (firstValue != null)
43 Option.just(firstValue)
44 else nextValues.asSequence()
46 .filter { it != null }