001/* 002 * Portions of this software was developed by employees of the National Institute 003 * of Standards and Technology (NIST), an agency of the Federal Government and is 004 * being made available as a public service. Pursuant to title 17 United States 005 * Code Section 105, works of NIST employees are not subject to copyright 006 * protection in the United States. This software may be subject to foreign 007 * copyright. Permission in the United States and in foreign countries, to the 008 * extent that NIST may hold copyright, to use, copy, modify, create derivative 009 * works, and distribute this software and its documentation without fee is hereby 010 * granted on a non-exclusive basis, provided that this notice and disclaimer 011 * of warranty appears in all copies. 012 * 013 * THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER 014 * EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY 015 * THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF 016 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM 017 * INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE 018 * SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE. IN NO EVENT 019 * SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT, 020 * INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM, 021 * OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY, 022 * CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR 023 * PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT 024 * OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER. 025 */ 026 027package gov.nist.secauto.metaschema.core.metapath.function; 028 029import java.util.Objects; 030 031public enum Occurrence { 032 /** 033 * An empty sequence. 034 */ 035 ZERO("", true), 036 /** 037 * The occurrence indicator {@code "?"}. 038 */ 039 ZERO_OR_ONE("?", true), 040 /** 041 * No occurrence indicator. 042 */ 043 ONE("", false), 044 /** 045 * The occurrence indicator {@code "*"}. 046 */ 047 ZERO_OR_MORE("*", true), 048 /** 049 * The occurrence indicator {@code "+"}. 050 */ 051 ONE_OR_MORE("+", false); 052 053 private final String indicator; 054 private final boolean optional; 055 056 Occurrence(String indicator, boolean optional) { 057 Objects.requireNonNull(indicator, "indicator"); 058 this.indicator = indicator; 059 this.optional = optional; 060 } 061 062 /** 063 * Get the occurrence indicator to use in the signature string for the argument. 064 * 065 * @return the occurrence indicator 066 */ 067 public String getIndicator() { 068 return indicator; 069 } 070 071 /** 072 * Determine if providing a value is optional based on the occurrence. 073 * 074 * @return {@code true} if providing a value is optional or {@code false} if 075 * required 076 */ 077 public boolean isOptional() { 078 return optional; 079 } 080}