anchor.diff:  make_token_transform(#{transform := casefold}) ->
       'CASEFOLD';
   make_token_transform(_) ->
  -    asn1_NOVALUE.
  +    undefined.
   
   make_token_add_filter(#{add := L}) when is_list(L) ->
       L;
  
positive.code: 			 threshold = <<>>,
  			 set_value = <<>>}.
  
  -spec make_index_config(IndexConfig :: [map()]) ->
      [#'IndexConfig'{}].
  make_index_config(IndexConfig) ->
      make_index_config(IndexConfig, []).
  
  make_index_config([#{column := Column, options := Config} | Rest], Acc) ->
      IndexConfig = #'IndexConfig'{column = Column,
  				 options = make_index_option(Config)},
      make_index_config(Rest, [IndexConfig | Acc]);
  make_index_config([], Acc) ->
      lists:reverse(Acc).
  
  make_index_option(Config) ->
     #'IndexOptions'{char_filter = make_char_filter(Config),
  		   tokenizer = make_tokenizer(Config),
  		   token_filter = make_token_filter(Config)}.
  
  make_char_filter(#{char_filter := nfc}) ->
      'NFC';
  
negative.code: make_char_filter(#{char_filter := nfkd}) ->
      'NFKD';
  make_char_filter(_) ->
      undefined.
  
  make_tokenizer(#{tokenizer := unicode_word_boundaries}) ->
      'UNICODE_WORD_BOUNDARIES';
  make_tokenizer(_) ->
      undefined.
  
  make_token_filter(#{token_filter := TokenFilter} ) ->
      #'TokenFilter'{transform = make_token_transform(TokenFilter),
  