src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/regexp/joni/ast/BackRefNode.java

/*
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 * 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 NONINFRINGEMENT. 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 jdk.nashorn.internal.runtime.regexp.joni.ast;

import jdk.nashorn.internal.runtime.regexp.joni.ScanEnvironment;

public final class BackRefNode extends StateNode {
    public final int backRef;

    public BackRefNode(final int backRef, final ScanEnvironment env) {
        this.backRef = backRef;

        if (backRef <= env.numMem && env.memNodes[backRef] == null) {
            setRecursion(); /* /...(\1).../ */
        }
    }

    @Override
    public int getType() {
        return BREF;
    }

    @Override
    public String getName() {
        return "Back Ref";
    }

    @Override
    public String toString(final int level) {
        final StringBuilder value = new StringBuilder(super.toString(level));
        value.append("\n  back: ").append(backRef);
        return value.toString();
    }
}