anchor.diff:      opt_value: Options.option_val;
       opt_default: Options.option_val;
       opt_type: Options.opt_type;
  -    opt_snippet: string;
  +    opt_snippets: list<string>;
       opt_documentation: option<string>;
       opt_permission_level: fstar_option_permission_level }
   
  
positive.code: 
    run_autocomplete' st search_term filter
  
  let candidate_of_fstar_option match_len is_reset opt =
    // let may_set =
    //   match opt.opt_permission_level with
    //   | OptSet -> true
    //   | OptReset -> is_reset
    //   | ReadOnly -> false in
    // let annot =
    //   if may_set
    // FIXME meta string (on annotation, or as a new primitive?
    { CompletionTable.completion_match_length = match_len;
      CompletionTable.completion_candidate = opt.opt_snippet;
      CompletionTable.completion_annotation = kind_of_fstar_option_type opt.opt_type }
  
  let run_option_autocomplete st search_term is_reset =
    let matcher opt = Util.starts_with opt.opt_snippet search_term in
    let options = collect_fstar_options matcher in
    let c_of_opt = candidate_of_fstar_option (String.length search_term) is_reset in
    let results = List.map c_of_opt options in
    let json = List.map CompletionTable.json_of_completion_result results in
    ((QueryOK, JsonList json), Inl st)
  
  let run_autocomplete st search_term kind =
    match kind with
  
negative.code:                opt_value = Options.Unset;
                 opt_default = default_value;
                 opt_type = typ;
                 opt_snippets = snippets_of_fstar_option name typ;
                 opt_documentation = if doc = "" then None else Some doc;
                 opt_permission_level = if Options.settable name then OptSet
                                        else if Options.resettable name then OptReset
                                        else OptReadOnly }))
    |> List.sortWith (fun o1 o2 ->
          String.compare (String.lowercase (o1.opt_name))
                         (String.lowercase (o2.opt_name)))
  
  let collect_fstar_options (filter: fstar_option -> bool) =
    let filter_update opt =
  