/*
 * Copyright (c) 2024, 2025, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */

package compiler.lib.generators;

import java.util.NavigableSet;

/**
 * Selects values from a pre-defined list.
 */
final class RestrictableRandomElementGenerator<T extends Comparable<T>> extends RandomElementGenerator<T> implements RestrictableGenerator<T> {
    /*
     * Pre-generated values we can choose from. Maintained for restriction.
     */
    private final NavigableSet<T> values;

    public RestrictableRandomElementGenerator(Generators g, NavigableSet<T> values) {
        super(g, values);
        if (values.isEmpty()) throw new EmptyGeneratorException();
        this.values = values;
    }

    @Override
    public RestrictableGenerator<T> restricted(T newLo, T newHi) {
        return new RestrictableRandomElementGenerator<>(g, values.subSet(newLo, true, newHi, true));
    }
}