/*
* Copyright 2003-2017 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.impl.interpreted;
import jetbrains.mps.generator.impl.GenerationFailureException;
import jetbrains.mps.generator.impl.GeneratorUtil;
import jetbrains.mps.generator.impl.RuleConsequenceProcessor;
import jetbrains.mps.generator.impl.RuleUtil;
import jetbrains.mps.generator.impl.TemplateProcessingFailureException;
import jetbrains.mps.generator.impl.query.PatternRuleQuery;
import jetbrains.mps.generator.impl.query.QueryKeyImpl;
import jetbrains.mps.generator.runtime.GenerationException;
import jetbrains.mps.generator.runtime.ReductionRuleBase;
import jetbrains.mps.generator.runtime.TemplateContext;
import jetbrains.mps.generator.runtime.TemplateExecutionEnvironment;
import jetbrains.mps.generator.runtime.TemplateReductionRule;
import jetbrains.mps.generator.template.PatternRuleContext;
import jetbrains.mps.lang.pattern.GeneratedMatchingPattern;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.mps.openapi.model.SNode;
import java.util.Collection;
/**
* Evgeny Gryaznov, 11/23/10
*/
public class TemplateReductionPatternRuleInterpreted extends ReductionRuleBase implements TemplateReductionRule {
private final SNode myRuleNode;
private final String myRuleMappingName;
private final RuleConsequenceProcessor myRuleConsequence;
private PatternRuleQuery myQuery;
public TemplateReductionPatternRuleInterpreted(SNode ruleNode) {
super(ruleNode.getReference(), RuleUtil.getPatternReductionRulePatternNodeConcept(ruleNode), false);
myRuleNode = ruleNode;
myRuleMappingName = RuleUtil.getPatternReductionRuleLabel(ruleNode);
final SNode rc = RuleUtil.getPatternReductionRuleConsequence(ruleNode);
myRuleConsequence = rc == null ? null : RuleConsequenceProcessor.prepare(rc);
}
@Override
public Collection<SNode> apply(@NotNull TemplateContext context) throws GenerationException {
GeneratedMatchingPattern pattern = checkIfApplicable(context.getEnvironment(), context);
if (pattern == null) {
return null;
}
// the order of subContext is important - first pattern, then mapping name: subContext(Pattern) drops mapping name
context = context.subContext(pattern);
if (myRuleConsequence == null) {
throw new TemplateProcessingFailureException(myRuleNode, "no rule consequence", GeneratorUtil.describeInput(context));
}
return myRuleConsequence.processRuleConsequence(context.subContext(myRuleMappingName));
}
private GeneratedMatchingPattern checkIfApplicable(TemplateExecutionEnvironment env, TemplateContext context) throws GenerationFailureException {
if (myQuery == null) {
// There are pattern : PatternExpression[1] and conditionFunction : BaseMappingRule_Condition[0..1] in PatternReduction_MappingRule,
// and unlike other rules, getPatternRuleCondition() here corresponds to mandatory QG.checkPattern method,
// which invokes conditionFunction if present.
myQuery = env.getQueryProvider(getRuleNode()).getPatternRuleCondition(new QueryKeyImpl(getRuleNode(), getRuleNode().getNodeId(), myRuleNode));
}
return myQuery.pattern(new PatternRuleContext(context, getRuleNode()));
}
}