/**
* Licensed to Odiago, Inc. under one or more contributor license
* agreements. See the NOTICE.txt file distributed with this work for
* additional information regarding copyright ownership. Odiago, Inc.
* 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.odiago.flumebase.exec.builtins;
import java.util.Collections;
import java.util.List;
import com.odiago.flumebase.exec.EventWrapper;
import com.odiago.flumebase.lang.ListType;
import com.odiago.flumebase.lang.NullableType;
import com.odiago.flumebase.lang.ScalarFunc;
import com.odiago.flumebase.lang.Type;
import com.odiago.flumebase.lang.UniversalType;
/**
* Return the number of elements in a list.
* Return null if the list is null.
*/
public class size extends ScalarFunc {
private UniversalType mArgType;
public size() {
mArgType = new UniversalType("'a");
mArgType.addConstraint(Type.getNullable(Type.TypeName.TYPECLASS_ANY));
}
@Override
public Type getReturnType() {
return Type.getNullable(Type.TypeName.INT);
}
@Override
public Object eval(EventWrapper event, Object... args) {
List<Object> lst = (List<Object>) args[0];
if (null == lst) {
return null;
} else {
return Integer.valueOf(lst.size());
}
}
@Override
public List<Type> getArgumentTypes() {
return Collections.singletonList((Type) new NullableType(new ListType(mArgType)));
}
}