com.hazelcast.jet.sql.impl.validate.operators.misc.HazelcastCoalesceFunction Maven / Gradle / Ivy
/*
* Copyright 2021 Hazelcast Inc.
*
* Licensed under the Hazelcast Community License (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://hazelcast.com/hazelcast-community-license
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hazelcast.jet.sql.impl.validate.operators.misc;
import com.hazelcast.jet.sql.impl.validate.HazelcastCallBinding;
import com.hazelcast.jet.sql.impl.validate.HazelcastSqlValidator;
import com.hazelcast.jet.sql.impl.validate.operators.common.HazelcastFunction;
import com.hazelcast.jet.sql.impl.validate.operators.typeinference.CoalesceOperandTypeInference;
import com.hazelcast.jet.sql.impl.validate.types.HazelcastTypeUtils;
import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.sql.SqlBasicCall;
import com.hazelcast.org.apache.calcite.sql.SqlFunctionCategory;
import com.hazelcast.org.apache.calcite.sql.SqlKind;
import com.hazelcast.org.apache.calcite.sql.SqlNode;
import com.hazelcast.org.apache.calcite.sql.SqlOperandCountRange;
import com.hazelcast.org.apache.calcite.sql.type.ReturnTypes;
import com.hazelcast.org.apache.calcite.sql.type.SqlOperandCountRanges;
import com.hazelcast.org.apache.calcite.sql.validate.SqlValidatorScope;
import java.util.ArrayList;
import java.util.List;
import static com.hazelcast.jet.sql.impl.validate.HazelcastResources.RESOURCES;
import static com.hazelcast.jet.sql.impl.validate.operators.typeinference.HazelcastReturnTypeInference.wrap;
public final class HazelcastCoalesceFunction extends HazelcastFunction {
public static final HazelcastCoalesceFunction INSTANCE = new HazelcastCoalesceFunction();
private HazelcastCoalesceFunction() {
super(
"COALESCE",
SqlKind.COALESCE,
wrap(ReturnTypes.ARG0_NULLABLE),
CoalesceOperandTypeInference.INSTANCE,
SqlFunctionCategory.SYSTEM);
}
@Override
public SqlOperandCountRange getOperandCountRange() {
return SqlOperandCountRanges.from(1);
}
@Override
protected boolean checkOperandTypes(HazelcastCallBinding callBinding, boolean throwOnFailure) {
HazelcastSqlValidator validator = callBinding.getValidator();
SqlValidatorScope scope = callBinding.getScope();
SqlBasicCall sqlCall = (SqlBasicCall) callBinding.getCall();
List operandList = sqlCall.getOperandList();
List argTypes = new ArrayList<>(operandList.size());
for (SqlNode node : operandList) {
argTypes.add(validator.deriveType(scope, node));
}
assert !argTypes.isEmpty();
RelDataType returnType = argTypes.stream().reduce(HazelcastTypeUtils::withHigherPrecedence).get();
for (int i = 0; i < operandList.size(); i++) {
int finalI = i;
boolean elementTypeCoerced = validator.getTypeCoercion().rowTypeElementCoercion(
scope,
operandList.get(i),
returnType,
sqlNode -> sqlCall.setOperand(finalI, sqlNode));
if (!elementTypeCoerced) {
if (throwOnFailure) {
throw validator.newValidationError(sqlCall, RESOURCES.cannotInferCaseResult(argTypes.toString(), getName()));
} else {
return false;
}
}
}
return true;
}
}