io.opencensus.common.ToLongFunction Maven / Gradle / Ivy
/*
* Copyright 2018, OpenCensus Authors
*
* 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.
*/
package io.opencensus.common;
/*>>>
import org.checkerframework.checker.nullness.qual.Nullable;
*/
/**
* Represents a function that produces a long-valued result. See {@link
* io.opencensus.metrics.MetricRegistry} for an example of its use.
*
* Note: This class is based on the java.util.ToLongFunction class added in Java 1.8. We cannot
* use the Function from Java 1.8 because this library is Java 1.6 compatible.
*
* @since 0.16
*/
public interface ToLongFunction {
/**
* Applies this function to the given argument.
*
* @param value the function argument.
* @return the function result.
*/
long applyAsLong(/*@Nullable*/ T value);
}