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 java.util.List;
30 import java.util.Objects;
31
32 import edu.umd.cs.findbugs.annotations.NonNull;
33
34 /**
35 * An immutable expression with a single sub-expression.
36 */
37 abstract class AbstractUnaryExpression
38 extends AbstractExpression {
39 @NonNull
40 private final IExpression expr;
41
42 /**
43 * Construct a new unary expression.
44 *
45 * @param expr
46 * the single sub-expression
47 */
48 public AbstractUnaryExpression(@NonNull IExpression expr) {
49 this.expr = Objects.requireNonNull(expr, "expr");
50 }
51
52 /**
53 * Retrieve the single child sub-expression.
54 *
55 * @return the sub-expression
56 */
57 @NonNull
58 public IExpression getChild() {
59 return expr;
60 }
61
62 @SuppressWarnings("null")
63 @Override
64 public List<? extends IExpression> getChildren() {
65 return List.of(expr);
66 }
67 }