sclass PartialAttractor 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(LS tok) {
    ret acceptFull();
  }
}

// uses find3
sclass PFind3Attractor > Attractor {
  S pattern;
  
  *(S *pattern) {}
  *(S *pattern, Runnable *action) {}
  
  public bool matches(S s) {
    ret find3(pattern, s);
  }
}

sclass YesAttractor > Attractor {
  *() {
    tester = f<S, Bool> isYes_1;
  }
  
  *(Runnable action) { this(); this.action = action; }
}