IExpression.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
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* SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE. IN NO EVENT
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* INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
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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;
public interface IExpression {
/**
* Retrieve the child expressions associated with this expression.
*
* @return a list of expressions, which may be empty
*/
@NonNull
List<? extends IExpression> getChildren();
/**
* The minimum expected result type to be produced when evaluating the
* expression. The result may be a sub-class or sub-interface of this value.
*
* @return the base result type
*/
@NonNull
default Class<? extends IItem> getBaseResultType() {
return IItem.class;
}
/**
* The expected result type produced by evaluating the expression. The result
* must be the same or a sub-class or sub-interface of the value provided by
* {@link #getBaseResultType()}.
* <p>
* This method can be overloaded to provide static analysis of the expression to
* determine a more specific result type.
*
* @return the result type
*/
@NonNull
default Class<? extends IItem> getStaticResultType() {
return getBaseResultType();
}
/**
* Produce a string representation of this expression including the expression's
* name.
* <p>
* This method can be overloaded to provide a more appropriate representation of
* the expression.
*
* @return a string representing the data elements of the expression
*/
@SuppressWarnings("null")
@NonNull
default String toASTString() {
return String.format("%s[]", getClass().getName());
}
/**
* Provides a double dispatch callback for visitor handling.
*
* @param dynamicContext
* the dynamic evaluation context
* @param focus
* the outer focus of the expression
* @return the result of evaluation
*/
@NonNull
ISequence<? extends IItem> accept(@NonNull DynamicContext dynamicContext, @NonNull ISequence<?> focus);
/**
* Provides a double dispatch callback for visitor handling.
*
* @param <RESULT>
* the type of the evaluation result
* @param <CONTEXT>
* the type of the visitor context
* @param visitor
* the visitor calling this method
* @param context
* the visitor context
* @return the result of evaluation
*/
<RESULT, CONTEXT> RESULT accept(@NonNull IExpressionVisitor<RESULT, CONTEXT> visitor, @NonNull CONTEXT context);
}