dev.cel.common.internal.BidiConverter Maven / Gradle / Ivy
// Copyright 2022 Google LLC
//
// 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
//
// https://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 dev.cel.common.internal;
import com.google.auto.value.AutoValue;
import com.google.errorprone.annotations.CheckReturnValue;
import dev.cel.common.annotations.Internal;
/**
* The {@code BidiConverter} is a bidirectional converter which contains {@code Converter} objects
* to forward convert from proto to CEL and backward convert from CEL to proto.
*
* Use the {@code BidiConverter} when dealing with reading and constructing proto messages during
* expression interpretation as CEL numeric primitives are wider than many of the proto primitives.
*
*
CEL Library Internals. Do Not Use.
*
* @param The proto value type.
* @param The CEL value type.
*/
@AutoValue
@CheckReturnValue
@Internal
public abstract class BidiConverter {
/** A {@code BidiConverter} used for objects which do not need conversion. */
public static final BidiConverter IDENTITY =
BidiConverter.of(value -> value, value -> value);
/** Return the {@code Converter} which adapts from proto values to CEL values. */
public abstract Converter forwardConverter();
/** Return the {@code Converter} which adapts from CEL values to proto values. */
public abstract Converter backwardConverter();
/** Return a {@code BidiConverter} with the converter references reversed. */
public BidiConverter reverse() {
return of(backwardConverter(), forwardConverter());
}
/**
* Create a new {@code BidiConverter} from the {@code forwardConverter} and {@code
* backwardConverter} {@link Converter} objects.
*/
public static BidiConverter of(
Converter forwardConverter, Converter backwardConverter) {
return new AutoValue_BidiConverter<>(forwardConverter, backwardConverter);
}
public static BidiConverter identity() {
return new AutoValue_BidiConverter<>(value -> value, value -> value);
}
}