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.function;
28
29 import java.util.Objects;
30
31 public enum Occurrence {
32 /**
33 * An empty sequence.
34 */
35 ZERO("", true),
36 /**
37 * The occurrence indicator {@code "?"}.
38 */
39 ZERO_OR_ONE("?", true),
40 /**
41 * No occurrence indicator.
42 */
43 ONE("", false),
44 /**
45 * The occurrence indicator {@code "*"}.
46 */
47 ZERO_OR_MORE("*", true),
48 /**
49 * The occurrence indicator {@code "+"}.
50 */
51 ONE_OR_MORE("+", false);
52
53 private final String indicator;
54 private final boolean optional;
55
56 Occurrence(String indicator, boolean optional) {
57 Objects.requireNonNull(indicator, "indicator");
58 this.indicator = indicator;
59 this.optional = optional;
60 }
61
62 /**
63 * Get the occurrence indicator to use in the signature string for the argument.
64 *
65 * @return the occurrence indicator
66 */
67 public String getIndicator() {
68 return indicator;
69 }
70
71 /**
72 * Determine if providing a value is optional based on the occurrence.
73 *
74 * @return {@code true} if providing a value is optional or {@code false} if
75 * required
76 */
77 public boolean isOptional() {
78 return optional;
79 }
80 }