/*
* 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 com.facebook.presto.metadata;
import com.facebook.presto.operator.scalar.ScalarFunctionImplementation;
import com.facebook.presto.spi.type.TypeManager;
import static com.facebook.presto.metadata.FunctionKind.SCALAR;
import static com.google.common.base.Preconditions.checkArgument;
import static java.util.Objects.requireNonNull;
public abstract class SqlScalarFunction
implements SqlFunction
{
private final Signature signature;
protected SqlScalarFunction(Signature signature)
{
this.signature = requireNonNull(signature, "signature is null");
checkArgument(signature.getKind() == SCALAR, "function kind must be SCALAR");
}
@Override
public final Signature getSignature()
{
return signature;
}
public abstract ScalarFunctionImplementation specialize(BoundVariables boundVariables, int arity, TypeManager typeManager, FunctionRegistry functionRegistry);
public static SqlScalarFunctionBuilder builder(Class<?> clazz)
{
return new SqlScalarFunctionBuilder(clazz);
}
}