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.iri.namespace.repo;
019
020import org.jspecify.annotations.Nullable;
021
022import java.util.Collections;
023import java.util.Optional;
024
025public final class EmptyNamespaceRepository implements NamespaceRepository {
026
027    public static final NamespaceRepository INSTANCE = new EmptyNamespaceRepository();
028
029    private EmptyNamespaceRepository() {}
030
031    @Override
032    public Optional<String> getIRI(String prefix) {
033        return Optional.empty();
034    }
035
036    @Override
037    public Iterable<String> listIRI() {
038        return Collections.emptySet();
039    }
040
041    @Override
042    public @Nullable Namespace get(String iri) {
043        return null;
044    }
045}