cqfn/eo

/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2016-2024 Objectionary.com
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package org.eolang;

/**
 * Absent attribute.
 *
 * This class exists only because we want to have nice and informative
 * error messages for the attributes that are absent, but are being
 * written or read.
 *
 * @since 0.1
 */
@Versionized
final class AtAbsent extends AtEnvelope {
    /**
     * Ctor.
     * @param attr Attribute name
     * @param sfx Suffix
     */
    AtAbsent(final String attr, final String sfx) {
        super(
            new AtGetOnly(
                () -> {
                    throw new ExUnset(
                        String.format(
                            "Can't get(), attribute \"%s\" is absent%s",
                            attr, sfx
                        )
                    );
                }
            )
        );
    }
}