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.atomic.IAnyAtomicItem; 30 31 import edu.umd.cs.findbugs.annotations.NonNull; 32 import edu.umd.cs.findbugs.annotations.Nullable; 33 34 abstract class AbstractBasicArithmeticExpression 35 extends AbstractArithmeticExpression<IAnyAtomicItem> { 36 37 /** 38 * An expression that represents a basic arithmetic operation on two values. 39 * 40 * @param left 41 * the first item 42 * @param right 43 * the second item 44 */ 45 public AbstractBasicArithmeticExpression(@NonNull IExpression left, @NonNull IExpression right) { 46 super(left, right, IAnyAtomicItem.class); 47 } 48 49 @Override 50 public Class<IAnyAtomicItem> getBaseResultType() { 51 return IAnyAtomicItem.class; 52 } 53 54 @Override 55 public ISequence<? extends IAnyAtomicItem> accept(DynamicContext dynamicContext, ISequence<?> focus) { 56 IAnyAtomicItem leftItem = getFirstDataItem(getLeft().accept(dynamicContext, focus), true); 57 IAnyAtomicItem rightItem = getFirstDataItem(getRight().accept(dynamicContext, focus), true); 58 59 return resultOrEmpty(leftItem, rightItem); 60 } 61 62 /** 63 * Setup the operation on two atomic items. 64 * 65 * @param leftItem 66 * the first item 67 * @param rightItem 68 * the second item 69 * @return the result of the operation or an empty {@link ISequence} if either 70 * item is {@code null} 71 */ 72 @NonNull 73 protected ISequence<? extends IAnyAtomicItem> resultOrEmpty( 74 @Nullable IAnyAtomicItem leftItem, 75 @Nullable IAnyAtomicItem rightItem) { 76 ISequence<? extends IAnyAtomicItem> retval; 77 if (leftItem == null || rightItem == null) { 78 retval = ISequence.empty(); 79 } else { 80 IAnyAtomicItem result = operation(leftItem, rightItem); 81 retval = ISequence.of(result); 82 } 83 return retval; 84 } 85 86 /** 87 * Performs the arithmetic operation using the two provided values. 88 * 89 * @param left 90 * the first item 91 * @param right 92 * the second item 93 * @return the result of the operation 94 */ 95 @NonNull 96 protected abstract IAnyAtomicItem operation(@NonNull IAnyAtomicItem left, @NonNull IAnyAtomicItem right); 97 }