StatisticalDigestParametricType.java

/*
 * 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.common.type;

import java.util.List;

import static java.lang.String.format;

public abstract class StatisticalDigestParametricType
        implements ParametricType
{
    @Override
    public Type createType(List<TypeParameter> parameters)
    {
        checkArgument(parameters.size() == 1, "%s type expects exactly one type as a parameter, got %s", this.getName(), parameters);
        checkArgument(
                parameters.get(0).getKind() == ParameterKind.TYPE,
                "%s expects type as a parameter, got %s",
                this.getName(),
                parameters);
        // Validation check on the acceptable type (bigint, real, double) intentionally omitted
        // because this is validated in each function and to allow for consistent error messaging
        return getType(parameters);
    }

    protected abstract Type getType(List<TypeParameter> parameters);

    protected static void checkArgument(boolean argument, String format, Object... args)
    {
        if (!argument) {
            throw new IllegalArgumentException(format(format, args));
        }
    }
}