001/*
002 * SPDX-License-Identifier: Apache-2.0
003 *
004 * Copyright 2024-2026 The Enola <https://enola.dev> Authors
005 *
006 * Licensed under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 *     https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package dev.enola.data;
019
020import com.google.errorprone.annotations.ThreadSafe;
021
022import java.io.UncheckedIOException;
023
024/**
025 * Providers "provide" (AKA "load" or allow you to "get") a value (V), given a key (K).
026 *
027 * @param <K> the type of keys
028 * @param <V> the type of values
029 */
030@ThreadSafe
031public interface Provider<K, V> {
032
033    /**
034     * Get.
035     *
036     * @param key Key, never null
037     * @return value, or null if there is no Value for the given key
038     */
039    // NB: Intentionally NOT @Nullable, should throw, or return a default (like AlwaysThingProvider)
040    V get(K key) throws IllegalArgumentException, UncheckedIOException;
041}