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1   /*
2    * Portions of this software was developed by employees of the National Institute
3    * of Standards and Technology (NIST), an agency of the Federal Government and is
4    * being made available as a public service. Pursuant to title 17 United States
5    * Code Section 105, works of NIST employees are not subject to copyright
6    * protection in the United States. This software may be subject to foreign
7    * copyright. Permission in the United States and in foreign countries, to the
8    * extent that NIST may hold copyright, to use, copy, modify, create derivative
9    * works, and distribute this software and its documentation without fee is hereby
10   * granted on a non-exclusive basis, provided that this notice and disclaimer
11   * of warranty appears in all copies.
12   *
13   * THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
14   * EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
15   * THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
16   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
17   * INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
18   * SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE.  IN NO EVENT
19   * SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
20   * INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
21   * OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
22   * CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
23   * PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
24   * OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
25   */
26  
27  package gov.nist.secauto.metaschema.core.metapath;
28  
29  import gov.nist.secauto.metaschema.core.metapath.item.ItemUtils;
30  import gov.nist.secauto.metaschema.core.metapath.item.node.IModelNodeItem;
31  import gov.nist.secauto.metaschema.core.metapath.item.node.INodeItem;
32  
33  import java.util.List;
34  import java.util.stream.Stream;
35  
36  import edu.umd.cs.findbugs.annotations.NonNull;
37  
38  @SuppressWarnings("rawtypes")
39  class ModelInstance
40      extends AbstractNamedInstanceExpression<IModelNodeItem> {
41  
42    /**
43     * Construct a new expression that finds any child {@link IModelNodeItem} that
44     * matches the provided {@code test}.
45     *
46     * @param test
47     *          the test to use to match
48     */
49    protected ModelInstance(@NonNull IExpression test) {
50      super(test);
51    }
52  
53    @Override
54    public Class<IModelNodeItem> getBaseResultType() {
55      return IModelNodeItem.class;
56    }
57  
58    @Override
59    public <RESULT, CONTEXT> RESULT accept(IExpressionVisitor<RESULT, CONTEXT> visitor, CONTEXT context) {
60      return visitor.visitModelInstance(this, context);
61    }
62  
63    @Override
64    public ISequence<? extends IModelNodeItem<?, ?>> accept(
65        DynamicContext dynamicContext,
66        ISequence<?> focus) {
67      return ISequence.of(focus.asStream()
68          .map(item -> ItemUtils.checkItemIsNodeItemForStep(item))
69          .flatMap(item -> {
70            assert item != null;
71            return match(item);
72          }));
73    }
74  
75    /**
76     * Get a stream of matching child node items for the provided {@code context}.
77     *
78     * @param focusedItem
79     *          the node item to match child items of
80     * @return the stream of matching node items
81     */
82    @SuppressWarnings("null")
83    @NonNull
84    protected Stream<? extends IModelNodeItem<?, ?>> match(
85        @NonNull INodeItem focusedItem) {
86      Stream<? extends IModelNodeItem<?, ?>> retval;
87      if (getTest() instanceof Name) {
88        String name = ((Name) getTest()).getValue();
89        List<? extends IModelNodeItem<?, ?>> items = focusedItem.getModelItemsByName(name);
90        retval = items.stream();
91      } else {
92        // wildcard
93        retval = focusedItem.modelItems();
94      }
95      return retval;
96    }
97  }