!7

concept TheList {
  new L<S> entries;
}

p {
  db();
  if (isMainProgram()) botSleep();
}

synchronized answer {
  if "add * to list" {
    theList().entries.add($1);
    theList().change();
    ret "OK, has position " + l(theList().entries);
  }
  
  if "add * to list at position *" {
    int i = parseInt($2)-1;
    theList().entries.add(i, $1);
    theList().change();
    ret "OK";
  }
  
  if "take * out of list" {
    int i = theList().entries.indexOf($1);
    if (i < 0) ret "Not in list";
    else {
      theList().entries.remove(i);
      theList().change();
    }
    ret "OK, removed from position " + (i+1);
  }
  
  if "length of list"
    ret lstr(theList().entries);
    
  if "entry * in list" {
    S entry = get(theList().entries, parseInt($1)-1);
    ret entry == null ? "Nuttn" : "Entry: " + quote(entry);
  }
}

static TheList theList() {
  ret uniq(TheList);
}