diff options
Diffstat (limited to 'sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/arrow/core.kt')
-rw-r--r-- | sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/arrow/core.kt | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/arrow/core.kt b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/arrow/core.kt new file mode 100644 index 00000000..7381592d --- /dev/null +++ b/sources/hv-collector-utils/src/main/kotlin/org/onap/dcae/collectors/veshv/utils/arrow/core.kt @@ -0,0 +1,47 @@ +/* + * ============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.Option +import arrow.core.identity +import arrow.syntax.collections.firstOption +import java.util.concurrent.atomic.AtomicReference + +/** + * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com> + * @since July 2018 + */ + +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> 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() |