r/org.eclipse.statet.r.core/src/org/eclipse/statet/internal/r/core/sourcemodel/RSourceElements.java

/*=============================================================================#
 # Copyright (c) 2008, 2020 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.internal.r.core.sourcemodel;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.eclipse.statet.ltk.model.core.elements.IModelElement;
import org.eclipse.statet.r.core.model.IRLangSourceElement;


public class RSourceElements {
	
	static final List<? extends IRLangSourceElement> NO_R_SOURCE_CHILDREN= Collections.emptyList();
	
	static final List<? extends IRLangSourceElement> getChildren(final List<? extends IRLangSourceElement> children, final IModelElement.Filter filter) {
		if (filter == null) {
			return children;
		}
		else {
			final ArrayList<IRLangSourceElement> filtered= new ArrayList<>(children.size());
			for (final IRLangSourceElement child : children) {
				if (filter.include(child)) {
					filtered.add(child);
				}
			}
			return filtered;
		}
	}
	
	static final boolean hasChildren(final List<? extends IRLangSourceElement> children, final IModelElement.Filter filter) {
		if (filter == null) {
			return (!children.isEmpty());
		}
		else {
			for (final IRLangSourceElement child : children) {
				if (filter.include(child)) {
					return true;
				}
			}
			return false;
		}
	}
	
}