com.hazelcast.org.apache.calcite.sql.fun.SqlMapValueConstructor Maven / Gradle / Ivy

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SQL Parser and Optimizer
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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to you 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 com.hazelcast.org.apache.calcite.sql.fun;

import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.rel.type.RelDataTypeFactory;
import com.hazelcast.org.apache.calcite.sql.SqlCallBinding;
import com.hazelcast.org.apache.calcite.sql.SqlKind;
import com.hazelcast.org.apache.calcite.sql.SqlOperatorBinding;
import com.hazelcast.org.apache.calcite.sql.type.SqlTypeUtil;
import com.hazelcast.org.apache.calcite.util.Pair;
import com.hazelcast.org.apache.calcite.util.Util;

import com.hazelcast.org.checkerframework.checker.nullness.qual.Nullable;

import java.util.List;

import static com.hazelcast.org.apache.calcite.util.Static.RESOURCE;

import static java.util.Objects.requireNonNull;

/**
 * Definition of the MAP constructor,
 * MAP [<key>, <value>, ...].
 *
 * This is an extension to standard SQL.
 */
public class SqlMapValueConstructor extends SqlMultisetValueConstructor {
  public SqlMapValueConstructor() {
    super("MAP", SqlKind.MAP_VALUE_CONSTRUCTOR);
  }

  @Override public RelDataType inferReturnType(SqlOperatorBinding opBinding) {
    Pair<@Nullable RelDataType, @Nullable RelDataType> type =
        getComponentTypes(
            opBinding.getTypeFactory(), opBinding.collectOperandTypes());
    return SqlTypeUtil.createMapType(
        opBinding.getTypeFactory(),
        requireNonNull(type.left, "inferred key type"),
        requireNonNull(type.right, "inferred value type"),
        false);
  }

  @Override public boolean checkOperandTypes(
      SqlCallBinding callBinding,
      boolean throwOnFailure) {
    final List argTypes = SqlTypeUtil.deriveType(callBinding, callBinding.operands());
    if (argTypes.size() == 0) {
      throw callBinding.newValidationError(RESOURCE.mapRequiresTwoOrMoreArgs());
    }
    if (argTypes.size() % 2 > 0) {
      throw callBinding.newValidationError(RESOURCE.mapRequiresEvenArgCount());
    }
    final Pair<@Nullable RelDataType, @Nullable RelDataType> componentType =
        getComponentTypes(
            callBinding.getTypeFactory(), argTypes);
    if (null == componentType.left || null == componentType.right) {
      if (throwOnFailure) {
        throw callBinding.newValidationError(RESOURCE.needSameTypeParameter());
      }
      return false;
    }
    return true;
  }

  private static Pair<@Nullable RelDataType, @Nullable RelDataType> getComponentTypes(
      RelDataTypeFactory typeFactory,
      List argTypes) {
    return Pair.of(
        typeFactory.leastRestrictive(Util.quotientList(argTypes, 2, 0)),
        typeFactory.leastRestrictive(Util.quotientList(argTypes, 2, 1)));
  }
}