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 gov.nist.secauto.metaschema.core.metapath.item.IItem; 030 031import edu.umd.cs.findbugs.annotations.NonNull; 032 033public interface ISequenceType { 034 @NonNull 035 ISequenceType EMPTY = new ISequenceType() { 036 @Override 037 public boolean isEmpty() { 038 return true; 039 } 040 041 @Override 042 public Class<? extends IItem> getType() { 043 return null; 044 } 045 046 @Override 047 public Occurrence getOccurrence() { 048 return null; 049 } 050 051 @Override 052 public String toSignature() { 053 return "()"; 054 } 055 }; 056 057 /** 058 * Determine if the sequence is empty (if it holds any data) or not. 059 * 060 * @return {@code true} if the sequence is empty or {@code false} otherwise 061 */ 062 boolean isEmpty(); 063 064 /** 065 * Get the type of the sequence. 066 * 067 * @return the type of the sequence or {@code null} if the sequence is empty 068 */ 069 Class<? extends IItem> getType(); 070 071 /** 072 * Get the occurrence of the sequence. 073 * 074 * @return the occurrence of the sequence or {@code null} if the sequence is 075 * empty 076 */ 077 Occurrence getOccurrence(); 078 079 /** 080 * Get the signature of the function as a string. 081 * 082 * @return the signature 083 */ 084 String toSignature(); 085}