2 * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.yangtools.yang.model.api.meta;
10 import com.google.common.annotations.Beta;
11 import java.util.List;
13 import java.util.Optional;
14 import java.util.stream.Stream;
15 import org.eclipse.jdt.annotation.NonNull;
16 import org.eclipse.jdt.annotation.Nullable;
17 import org.opendaylight.yangtools.yang.common.Empty;
20 * Effective model statement which should be used to derive application behaviour.
22 * @param <A> Argument type ({@link Empty} if statement does not have argument.)
23 * @param <D> Class representing declared version of this statement.
25 public non-sealed interface EffectiveStatement<A, D extends DeclaredStatement<A>> extends ModelStatement<A> {
27 * Returns {@link StatementOrigin}, which denotes if statement was explicitly declared in original model or inferred
28 * during semantic processing of model.
31 * Implementations are required to return a {@link StatementOrigin}, consistent with {@link #getDeclared()}
32 * nullness. This is what the default implementation does and hence this method should never be explicitly
33 * implemented -- unless there is significant cost to the {@link #getDeclared()} implementation.
35 * @return statement origin.
37 default @NonNull StatementOrigin statementOrigin() {
38 return getDeclared() != null ? StatementOrigin.DECLARATION : StatementOrigin.CONTEXT;
42 * Returns statement, which was explicit declaration of this effective
45 * @return statement, which was explicit declaration of this effective
46 * statement or null if statement was inferred from context.
48 @Nullable D getDeclared();
51 * Returns value associated with supplied identifier.
53 * @param <K> Identifier type
54 * @param <V> Value type
55 * @param <N> Namespace identifier type
56 * @param namespace Namespace type
57 * @param identifier Identifier of element.
58 * @return Value if present
60 <K, V, N extends IdentifierNamespace<K, V>> @NonNull Optional<V> get(@NonNull Class<N> namespace,
61 @NonNull K identifier);
64 * Returns all local values from supplied namespace.
66 * @param <K> Identifier type
67 * @param <V> Value type
68 * @param <N> Namespace identifier type
69 * @param namespace Namespace type
70 * @return Key-value mappings, empty if the namespace does not exist.
71 * @throws NullPointerException if namespace is null
73 <K, V, N extends IdentifierNamespace<K, V>> @NonNull Map<K, V> getAll(@NonNull Class<N> namespace);
76 * Returns a collection of all effective substatements.
78 * @return collection of all effective substatements.
80 @NonNull List<? extends @NonNull EffectiveStatement<?, ?>> effectiveSubstatements();
83 * Find the first effective substatement of specified type.
85 * @param <T> substatement type
86 * @param type substatement type
87 * @return First effective substatement, or empty if no match is found.
90 default <T> Optional<T> findFirstEffectiveSubstatement(final @NonNull Class<T> type) {
91 return effectiveSubstatements().stream().filter(type::isInstance).findFirst().map(type::cast);
95 * Find the first effective substatement of specified type and return its value.
97 * @param <T> substatement type
98 * @param <V> substatement argument type
99 * @param type substatement type
100 * @return First effective substatement's argument, or empty if no match is found.
103 default <V, T extends EffectiveStatement<V, ?>> Optional<V> findFirstEffectiveSubstatementArgument(
104 final @NonNull Class<T> type) {
105 return findFirstEffectiveSubstatement(type).map(EffectiveStatement::argument);
109 * Find all effective substatements of specified type and return them as a stream.
111 * @param <T> substatement type
112 * @param type substatement type
113 * @return A stream of all effective substatements of specified type.
116 default <T extends EffectiveStatement<?, ?>> Stream<T> streamEffectiveSubstatements(final @NonNull Class<T> type) {
117 return effectiveSubstatements().stream().filter(type::isInstance).map(type::cast);