io.parsingdata.metal.expression.value.SingleValueExpression Maven / Gradle / Ivy
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/*
* Copyright 2013-2024 Netherlands Forensic Institute
* Copyright 2021-2024 Infix Technologies B.V.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.parsingdata.metal.expression.value;
import java.util.Optional;
import io.parsingdata.metal.data.ImmutableList;
import io.parsingdata.metal.data.ParseState;
import io.parsingdata.metal.encoding.Encoding;
/**
* Interface for all SingleValueExpression implementations.
*
* A SingleValueExpression is an expression that is evaluated by executing its
* {@link #evalSingle(ParseState, Encoding)} method. It yields an {@link Optional}
* {@link Value} object.
*
* As context, it receives the current ParseState object as
* well as the current Encoding object.
*/
@SuppressWarnings("FunctionalInterfaceMethodChanged") // What we do is in line with error-prone's advice
@FunctionalInterface
public interface SingleValueExpression extends ValueExpression {
Optional evalSingle(ParseState parseState, Encoding encoding);
@Override
default ImmutableList eval(ParseState parseState, Encoding encoding) {
return evalSingle(parseState, encoding)
.map(ImmutableList::create)
.orElseGet(ImmutableList::new);
}
}