asterix-om/src/main/java/edu/uci/ics/asterix/om/typecomputer/impl/OptionalADoubleTypeComputer.java

package edu.uci.ics.asterix.om.typecomputer.impl;

import java.util.ArrayList;
import java.util.List;

import edu.uci.ics.asterix.om.typecomputer.base.IResultTypeComputer;
import edu.uci.ics.asterix.om.types.AUnionType;
import edu.uci.ics.asterix.om.types.BuiltinType;
import edu.uci.ics.asterix.om.types.IAType;
import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
import edu.uci.ics.hyracks.algebricks.core.algebra.metadata.IMetadataProvider;
import edu.uci.ics.hyracks.algebricks.core.api.exceptions.AlgebricksException;

public class OptionalADoubleTypeComputer implements IResultTypeComputer {

    public static final OptionalADoubleTypeComputer INSTANCE = new OptionalADoubleTypeComputer();

    private OptionalADoubleTypeComputer() {
    }

    @Override
    public IAType computeType(ILogicalExpression expression, IVariableTypeEnvironment env,
            IMetadataProvider<?, ?> metadataProvider) throws AlgebricksException {
        List<IAType> unionList = new ArrayList<IAType>();
        unionList.add(BuiltinType.ANULL);
        unionList.add(BuiltinType.ADOUBLE);
        return new AUnionType(unionList, "OptionalDouble");
    }
}