AbstractFilterExpression.java
/*
* Portions of this software was developed by employees of the National Institute
* of Standards and Technology (NIST), an agency of the Federal Government and is
* being made available as a public service. Pursuant to title 17 United States
* Code Section 105, works of NIST employees are not subject to copyright
* protection in the United States. This software may be subject to foreign
* copyright. Permission in the United States and in foreign countries, to the
* extent that NIST may hold copyright, to use, copy, modify, create derivative
* works, and distribute this software and its documentation without fee is hereby
* granted on a non-exclusive basis, provided that this notice and disclaimer
* of warranty appears in all copies.
*
* THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
* EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
* THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
* INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
* SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE. IN NO EVENT
* SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
* INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
* OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
* CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
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* OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
*/
package gov.nist.secauto.metaschema.core.metapath;
import gov.nist.secauto.metaschema.core.metapath.item.IItem;
import java.util.List;
import edu.umd.cs.findbugs.annotations.NonNull;
abstract class AbstractFilterExpression
extends AbstractBinaryExpression<IExpression, IExpression> {
@NonNull
private final Class<? extends IItem> staticResultType;
/**
* Construct a new filter expression.
*
* @param left
* an expression indicating the items to filter
* @param right
* an expression indicating the items to use as the filter
*/
@SuppressWarnings("null")
public AbstractFilterExpression(@NonNull IExpression left, @NonNull IExpression right) {
super(left, right);
this.staticResultType = ExpressionUtils.analyzeStaticResultType(IItem.class, List.of(left, right));
}
@Override
public Class<? extends IItem> getStaticResultType() {
return staticResultType;
}
@Override
public ISequence<? extends IItem> accept(
@NonNull DynamicContext dynamicContext,
@NonNull ISequence<?> focus) {
ISequence<?> left = getLeft().accept(dynamicContext, focus);
ISequence<?> right = getRight().accept(dynamicContext, focus);
List<? extends IItem> rightList = right.asList();
return applyFilterTo(left, rightList);
}
/**
* A callback used to apply the filter to the result of evaluating the left
* expression.
*
* @param result
* the set of items to filter
* @param items
* a list of items to filter with
* @return the filtered result set
*/
@NonNull
protected abstract ISequence<?> applyFilterTo(
@NonNull ISequence<?> result,
@NonNull List<? extends IItem> items);
}