/*
* Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.yangtools.yang.model.api.meta;
import static java.util.Objects.requireNonNull;
import com.google.common.annotations.Beta;
import com.google.common.collect.Collections2;
import java.util.Collection;
import java.util.Optional;
import java.util.stream.Stream;
import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;
/**
* Represents declared statement.
*
* @param Argument type ({@link Void} if statement does not have argument.)
*/
public interface DeclaredStatement extends ModelStatement {
/**
* Returns statement argument as was present in original source.
*
* @return statement argument as was present in original source or null, if statement does not take argument.
*/
@Nullable String rawArgument();
/**
* Returns collection of explicitly declared child statements, while preserving its original ordering from original
* source.
*
* @return Collection of statements, which were explicitly declared in source of model.
*/
@NonNull Collection extends DeclaredStatement>> declaredSubstatements();
/**
* Returns collection of explicitly declared child statements, while preserving its original ordering from original
* source.
*
* @param substatement type
* @param type {@link DeclaredStatement} type
* @return Collection of statements, which were explicitly declared in source of model.
* @throws NullPointerException if {@code type} is null
*/
default > @NonNull Collection extends T> declaredSubstatements(
final Class type) {
requireNonNull(type);
return Collections2.transform(Collections2.filter(declaredSubstatements(), type::isInstance), type::cast);
}
/**
* Returns a {@link DeclarationReference} associated with this statement, if available.
*
* @apiNote
* This method does not contribute any semantic information and is provided purely as a conduit for
* implementation-specific information where a statement instance came from.
*
* @implSpec
* The default implementation returns {@link Optional#empty()}.
*
* @return A {@link DeclarationReference} associated with this statement or {@link Optional#empty()}.
*/
@Beta
default @NonNull Optional declarationReference() {
return Optional.empty();
}
/**
* Find the first effective substatement of specified type.
*
* @param substatement type
* @param type {@link DeclaredStatement} type
* @return First declared substatement, or empty if no match is found.
* @throws NullPointerException if {@code type} is null
*/
@Beta
default > @NonNull Optional findFirstDeclaredSubstatement(
@NonNull final Class type) {
requireNonNull(type);
return streamDeclaredSubstatements(type).filter(type::isInstance).findFirst().map(type::cast);
}
/**
* Find the first declared substatement of specified type and return its value.
*
* @param substatement type
* @param substatement argument type
* @param type {@link DeclaredStatement} type
* @return First declared substatement's argument, or empty if no match is found.
* @throws NullPointerException if {@code type} is null
*/
@Beta
default > @NonNull Optional findFirstDeclaredSubstatementArgument(
@NonNull final Class type) {
return findFirstDeclaredSubstatement(type).map(DeclaredStatement::argument);
}
/**
* Find all declared substatements of specified type and return them as a stream.
*
* @param substatement type
* @param type {@link DeclaredStatement} type
* @return A stream of all declared substatements of specified type.
* @throws NullPointerException if {@code type} is null
*/
@Beta
default > @NonNull Stream streamDeclaredSubstatements(
@NonNull final Class type) {
requireNonNull(type);
return declaredSubstatements().stream().filter(type::isInstance).map(type::cast);
}
}