io.trino.operator.scalar.EmptyMapConstructor Maven / Gradle / Ivy
/*
* 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 io.trino.operator.scalar;
import io.trino.spi.block.SqlMap;
import io.trino.spi.function.Description;
import io.trino.spi.function.ScalarFunction;
import io.trino.spi.function.SqlType;
import io.trino.spi.function.TypeParameter;
import io.trino.spi.type.MapType;
import io.trino.spi.type.Type;
import static io.trino.spi.block.MapValueBuilder.buildMapValue;
@Description("Creates an empty map")
@ScalarFunction("map")
public final class EmptyMapConstructor
{
private final SqlMap emptyMap;
public EmptyMapConstructor(@TypeParameter("map(unknown,unknown)") Type mapType)
{
emptyMap = buildMapValue(((MapType) mapType), 0, (keyBuilder, valueBuilder) -> {});
}
@SqlType("map(unknown,unknown)")
public SqlMap map()
{
return emptyMap;
}
}