// result of a (partial) parse. combines a value and a token range in a tokenization
// Good for bottom-up parsing
// See pwt_initial and EnglishDateParser
sclass ParsedWithTokens<A> extends Var<A> {
  LS tok; // full CNC token list being parsed
  int iStart; // points to first parsed C token
  int iRemaining; // points to first unparsed C token
  
  *() {}
  *(A a) { super(a); }
  *(A a, LS *tok, int *iStart, int *iRemaining) { super(a); }
  
  S parsedText() { ret joinSubList(tok, iStart | 1, iRemaining & ~1); }
  ListAndIndex<S> remaining() { ret ListAndIndex(tok, iRemaining); }
  ListAndIndex<S> start() { ret ListAndIndex(tok, iStart); }
  
  int length() { ret iRemaining-iStart; }
  
  <B> ParsedWithTokens<B> withValue(B b) {
    ret new ParsedWithTokens<B>(b, tok, iStart, iRemaining);
  }
  
  toString {
    ret "Parsed " + quote(parsedText()) + " as " + super.toString();
  }
  
  void replaceTokens(S s) {
    main replaceTokens(tok, iStart, iRemaining, s);
  }
}