/*
* Copyright 2003-2014 JetBrains s.r.o.
*
* 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 jetbrains.mps.generator;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.mps.openapi.model.SModelReference;
import org.jetbrains.mps.openapi.model.SNode;
import org.jetbrains.mps.openapi.model.SNodeId;
import org.jetbrains.mps.openapi.model.SNodeReference;
import java.util.List;
/**
* 2nd generation of generation (pun, sorry) trace facility.
* The idea is to record actual change rather to track each step with strict open/close semantic.
* Primary distinction is: lightweight (keep minimum), less use burden (few calls), multithread-friendly
*
* <p>
* Design note:
* Unlike existing IGenerationTracer, which is (singleton) project component, new trace facility
* is associated with transient model/module, and there's no need to pass it explicitly through GenerationOption
* </p>
* @author Artem Tikhomirov
*/
public interface GenerationTrace {
void nextStep(@NotNull SModelReference input, @NotNull SModelReference output);
void dropStep(@NotNull SModelReference input, @NotNull SModelReference output);
void trace(@Nullable SNodeId input, @NotNull List<SNodeId> output, @NotNull SNodeReference templateNode);
void walkForward(SNode node, @NotNull Visitor v);
void walkBackward(SNode node, @NotNull Visitor v);
public interface Visitor {
void beginStep(@NotNull SModelReference input, @NotNull SModelReference output);
// added, removed (although latter is hard to detect)?
void change(@NotNull SNodeReference input, @NotNull SNodeReference output, @NotNull SNodeReference template);
void endStep(@NotNull SModelReference input, @NotNull SModelReference output);
}
public class NoOp implements GenerationTrace {
@Override
public void nextStep(@NotNull SModelReference input, @NotNull SModelReference output) {
}
@Override
public void dropStep(@NotNull SModelReference input, @NotNull SModelReference output) {
}
@Override
public void trace(@Nullable SNodeId input, @NotNull List<SNodeId> output, @NotNull SNodeReference templateNode) {
}
@Override
public void walkForward(SNode node, Visitor v) {
// no-op
}
@Override
public void walkBackward(SNode node, Visitor v) {
// no-op
}
}
}