Axis.java
/*
* Portions of this software was developed by employees of the National Institute
* of Standards and Technology (NIST), an agency of the Federal Government and is
* being made available as a public service. Pursuant to title 17 United States
* Code Section 105, works of NIST employees are not subject to copyright
* protection in the United States. This software may be subject to foreign
* copyright. Permission in the United States and in foreign countries, to the
* extent that NIST may hold copyright, to use, copy, modify, create derivative
* works, and distribute this software and its documentation without fee is hereby
* granted on a non-exclusive basis, provided that this notice and disclaimer
* of warranty appears in all copies.
*
* THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
* EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
* THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
* INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
* SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE. IN NO EVENT
* SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
* INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
* OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
* CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
* PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
* OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
*/
package gov.nist.secauto.metaschema.core.metapath;
import gov.nist.secauto.metaschema.core.metapath.antlr.metapath10Lexer;
import gov.nist.secauto.metaschema.core.metapath.item.ItemUtils;
import gov.nist.secauto.metaschema.core.metapath.item.node.INodeItem;
import gov.nist.secauto.metaschema.core.util.CollectionUtil;
import gov.nist.secauto.metaschema.core.util.ObjectUtils;
import java.util.List;
import java.util.function.Function;
import java.util.stream.Stream;
import edu.umd.cs.findbugs.annotations.NonNull;
@SuppressWarnings("PMD.ShortClassName") // intentional
public enum Axis implements IExpression {
SELF(metapath10Lexer.KW_SELF, focus -> Stream.of(focus)),
PARENT(metapath10Lexer.KW_PARENT, focus -> Stream.ofNullable(focus.getParentNodeItem())),
ANCESTOR(metapath10Lexer.KW_ANCESTOR, INodeItem::ancestor),
ANCESTOR_OR_SELF(metapath10Lexer.KW_ANCESTOR_OR_SELF, INodeItem::ancestorOrSelf),
CHILDREN(metapath10Lexer.KW_CHILD, INodeItem::modelItems),
DESCENDANT(metapath10Lexer.KW_DESCENDANT, INodeItem::descendant),
DESCENDANT_OR_SELF(metapath10Lexer.KW_DESCENDANT_OR_SELF, INodeItem::descendantOrSelf);
private final int keywordIndex;
@NonNull
private final Function<INodeItem, Stream<? extends INodeItem>> action;
Axis(int keywordIndex, @NonNull Function<INodeItem, Stream<? extends INodeItem>> action) {
this.keywordIndex = keywordIndex;
this.action = action;
}
/**
* The ANTLR keyword for this axis type.
*
* @return the keyword
*/
public int getKeywordIndex() {
return keywordIndex;
}
/**
* Execute the axis operation on the provided {@code focus}.
*
* @param focus
* the node to operate on
* @return the result of the axis operation
*/
@NonNull
public Stream<? extends INodeItem> execute(@NonNull INodeItem focus) {
return ObjectUtils.notNull(action.apply(focus));
}
@Override
public List<? extends IExpression> getChildren() {
return CollectionUtil.emptyList();
}
@Override
public Class<INodeItem> getBaseResultType() {
return INodeItem.class;
}
@Override
public Class<INodeItem> getStaticResultType() {
return getBaseResultType();
}
@Override
public <RESULT, CONTEXT> RESULT accept(IExpressionVisitor<RESULT, CONTEXT> visitor, CONTEXT context) {
return visitor.visitAxis(this, context);
}
@Override
public ISequence<? extends INodeItem> accept(
DynamicContext dynamicContext,
ISequence<?> outerFocus) {
ISequence<? extends INodeItem> retval;
if (outerFocus.isEmpty()) {
retval = ISequence.empty();
} else {
retval = ISequence.of(outerFocus.asStream()
.map(item -> ItemUtils.checkItemIsNodeItemForStep(item))
.flatMap(item -> {
assert item != null;
return execute(item);
}).distinct());
}
return retval;
}
}