| /****************************************************************************** |
| * Copyright (c) 2018 TypeFox and others. |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v. 2.0 which is available at |
| * http://www.eclipse.org/legal/epl-2.0, |
| * or the Eclipse Distribution License v. 1.0 which is available at |
| * http://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause |
| ******************************************************************************/ |
| package org.eclipse.lsp4j.util; |
| |
| import java.util.ArrayDeque; |
| import java.util.Iterator; |
| import java.util.Queue; |
| |
| import org.eclipse.lsp4j.DocumentSymbol; |
| |
| /** |
| * Utilities for {@link DocumentSymbol document symbols}. |
| */ |
| public final class DocumentSymbols { |
| |
| /** |
| * Returns an unmodifiable iterator over the {@link DocumentSymbol document |
| * symbols} using the breath-first traversal. That is, all the symbols of depth |
| * 0 are returned, then depth 1, then 2, and so on. |
| * |
| * <p> |
| * It does not guarantee a well defined behavior of the resulting iterator if |
| * you modify the structure while the iteration is in progress. |
| */ |
| public static Iterator<DocumentSymbol> asIterator(DocumentSymbol documentSymbol) { |
| return new DocumentSymbolIterator(documentSymbol); |
| } |
| |
| protected static class DocumentSymbolIterator extends BreadthFirstIterator<DocumentSymbol> { |
| |
| protected DocumentSymbolIterator(DocumentSymbol documentSymbol) { |
| super(Preconditions.checkNotNull(documentSymbol, "documentSymbol")); |
| } |
| |
| @Override |
| protected Iterable<DocumentSymbol> getChildren(DocumentSymbol node) { |
| return node.getChildren(); |
| } |
| |
| } |
| |
| protected abstract static class BreadthFirstIterator<T> implements Iterator<T> { |
| |
| private Queue<T> queue; |
| |
| protected BreadthFirstIterator(T root) { |
| Preconditions.checkNotNull(root, "root"); |
| this.queue = new ArrayDeque<>(); |
| this.queue.add(root); |
| } |
| |
| @Override |
| public void remove() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public boolean hasNext() { |
| return !this.queue.isEmpty(); |
| } |
| |
| @Override |
| public T next() { |
| T result = queue.remove(); |
| Iterable<T> children = getChildren(result); |
| if (children != null) { |
| for (T child : children) { |
| queue.add(child); |
| } |
| } |
| return result; |
| } |
| |
| /** |
| * Returns with the children (direct descendants) of the {@code node} argument. |
| * If the argument does not have any children, clients are allowed to return |
| * {@code null}. |
| */ |
| protected abstract Iterable<T> getChildren(T node); |
| |
| } |
| |
| private DocumentSymbols() { |
| |
| } |
| |
| } |