/*
* Licensed to CRATE Technology GmbH ("Crate") under one or more contributor
* license agreements. See the NOTICE file distributed with this work for
* additional information regarding copyright ownership. Crate 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.
*
* However, if you have executed another commercial license agreement
* with Crate these terms will supersede the license and you may use the
* software solely pursuant to the terms of the relevant commercial agreement.
*/
package io.crate.operation.scalar.arithmetic;
import com.google.common.collect.ImmutableList;
import io.crate.metadata.*;
import io.crate.data.Input;
import io.crate.operation.scalar.ScalarFunctionModule;
import io.crate.types.DataType;
import javax.annotation.Nullable;
import java.util.List;
public class AbsFunction extends Scalar<Number, Number> {
public static final String NAME = "abs";
public static void register(ScalarFunctionModule module) {
module.register(NAME, new Resolver());
}
private final FunctionInfo info;
public AbsFunction(DataType dataType) {
this.info = new FunctionInfo(
new FunctionIdent(NAME, ImmutableList.of(dataType)), dataType);
}
@Override
public FunctionInfo info() {
return info;
}
@Override
public Number evaluate(Input<Number>... args) {
assert args.length == 1 : "number of args must be 1";
Number value = args[0].value();
if (value != null) {
return (Number) info.returnType().value(Math.abs(value.doubleValue()));
}
return null;
}
private static class Resolver implements FunctionResolver {
@Override
public FunctionImplementation getForTypes(List<DataType> dataTypes) throws IllegalArgumentException {
return new AbsFunction(dataTypes.get(0));
}
@Nullable
@Override
public List<DataType> getSignature(List<DataType> dataTypes) {
return Signature.SIGNATURES_SINGLE_NUMERIC.apply(dataTypes);
}
}
}