Method removeFrom

guava/src/com/google/common/base/CharMatcher.java:618–645

Returns a string containing all non-matching characters of a character sequence, in order. For example: {@snippet : CharMatcher.is('a').removeFrom("bazaar") } ... returns {@code "bzr"}.

(CharSequence sequence)

   * ... returns {@code "bzr"}.
   */
  public String removeFrom(CharSequence sequence) {
    String string = sequence.toString();
    int pos = indexIn(string);
    if (pos == -1) {
      return string;
    }

    char[] chars = string.toCharArray();
    int spread = 1;

    // This unusual loop comes from extensive benchmarking
    OUT:
    while (true) {
      pos++;
      while (true) {
        if (pos == chars.length) {
          break OUT;
        }
        if (matches(chars[pos])) {
          break;
        }
        chars[pos - spread] = chars[pos];
        pos++;
      }
      spread++;
    }
    return new String(chars, 0, pos - spread);
  }

  /**
   * Returns a string containing all matching BMP characters of a character sequence, in order. For