001/*
002 * Portions of this software was developed by employees of the National Institute
003 * of Standards and Technology (NIST), an agency of the Federal Government and is
004 * being made available as a public service. Pursuant to title 17 United States
005 * Code Section 105, works of NIST employees are not subject to copyright
006 * protection in the United States. This software may be subject to foreign
007 * copyright. Permission in the United States and in foreign countries, to the
008 * extent that NIST may hold copyright, to use, copy, modify, create derivative
009 * works, and distribute this software and its documentation without fee is hereby
010 * granted on a non-exclusive basis, provided that this notice and disclaimer
011 * of warranty appears in all copies.
012 *
013 * THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
014 * EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
015 * THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
016 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
017 * INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
018 * SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE.  IN NO EVENT
019 * SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
020 * INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
021 * OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
022 * CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
023 * PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
024 * OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
025 */
026
027package gov.nist.secauto.metaschema.core.util;
028
029import java.util.function.Function;
030import java.util.regex.Matcher;
031import java.util.regex.Pattern;
032
033import edu.umd.cs.findbugs.annotations.NonNull;
034
035public final class ReplacementScanner {
036  private ReplacementScanner() {
037    // disable construction
038  }
039
040  /**
041   * Search for instances of {@code pattern} in {@code text}. Replace each
042   * matching occurrence using the {@code replacementFunction}.
043   *
044   * @param text
045   *          the text to search
046   * @param pattern
047   *          the pattern to search for
048   * @param replacementFunction
049   *          a function that will provided the replacement text
050   * @return the resulting text after replacing matching occurrences in
051   *         {@code text}
052   */
053  public static CharSequence replaceTokens(@NonNull CharSequence text, @NonNull Pattern pattern,
054      Function<Matcher, CharSequence> replacementFunction) {
055    int lastIndex = 0;
056    StringBuilder retval = new StringBuilder();
057    Matcher matcher = pattern.matcher(text);
058    while (matcher.find()) {
059      retval.append(text, lastIndex, matcher.start())
060          .append(replacementFunction.apply(matcher));
061
062      lastIndex = matcher.end();
063    }
064    if (lastIndex < text.length()) {
065      retval.append(text, lastIndex, text.length());
066    }
067    return retval;
068  }
069}