sclass PartialAttractor implements Runnable {
  VF1<PartialAttractor> action;
  
  LS tok;
  IntRange matchedRange;

  public abstract bool find(); // uses tok
  public void run { callF(action, this); }
  
  toString { ret standard_toString(this); }
  
  bool acceptFull() {
    matchedRange = intRange(0, tok);
    true;
  }
}

// attracts everything
sclass PDefaultAttractor > Attractor {
  public abstract bool find() {
    ret acceptFull();
  }
}

// uses find3
sclass PFind3Attractor > Attractor {
  S pattern;
  
  *(S *pattern) {}

  public abstract bool find() {
    matchedRange = find2_range(pattern, s);
    ret matchedRange != null;
  }
}