anchor.diff:                                ),
     DefaultReaderFun = fun(_, _) -> default end,
     ok  = 'clojerl.Var':push_bindings(#{DefaultReaderFunVar => DefaultReaderFun}),
  -  default = clj_reader:read(<<"#whatever :tag">>),
  -  default = clj_reader:read(<<"#we use">>),
  +  default = ReadFun(<<"#whatever :tag">>),
  +  default = ReadFun(<<"#we use">>),
     ok  = 'clojerl.Var':pop_bindings(),
   
     ct:comment("Provide additional reader"),
  
positive.code:                                     ),
  
    ok  = 'clojerl.Var':push_bindings(#{DataReadersVar => DataReaders}),
    bla = clj_reader:read(<<"#bla 1">>),
    ok  = 'clojerl.Var':pop_bindings(),
  
    ct:comment("Don't provide a symbol"),
    ok = try clj_reader:read(<<"#1">>), error
         catch _:<<"?:1:2: Reader tag must be a symbol">> -> ok end,
  
    ct:comment("Provide a missing reader"),
    ok = try clj_reader:read(<<"#bla 1">>), error
         catch _:<<"?:1:2: No reader function for tag bla">> -> ok end,
  
    meck:unload('clojure.core'),
  
    {comments, ""}.
  
  -spec read_io(binary()) -> any().
  read_io(Src) ->
    Reader = 'erlang.io.StringReader':?CONSTRUCTOR(Src),
    clj_reader:read(<<>>, #{?OPT_IO_READER => Reader}).
  
  -spec read(binary()) -> any().
  read(Src) ->
    clj_reader:read(Src).
  
  -spec read_all_io(binary()) -> any().
  read_all_io(Src) ->
  
negative.code:   , HelloKeywordCheck
    , 2.5
    , WorldSymbolCheck
    } = ReadFun(<<"#[42, :hello, 2.5, world]">>),
    true = clj_core:equiv(HelloKeyword, HelloKeywordCheck),
    true = clj_core:equiv(WorldSymbol, WorldSymbolCheck),
  
    ct:comment("Read a tuple whose first element is an keyword"),
    T = ReadFun(<<"#[:random, :hello, 2.5, 'world]">>),
    'clojerl.erlang.Tuple' = clj_core:type(T),
  
    {comments, ""}.
  
  tagged(Config) when is_list(Config) ->
    tagged(fun read/1),
    tagged(fun read_io/1);
  tagged(ReadFun) ->
    DefaultDataReadersVar = 'clojerl.Var':?CONSTRUCTOR( <<"clojure.core">>
                                                      , <<"default-data-readers">>
                                                      ),
  