anchor.diff:      quote_plus(integer_to_list(Int));
   quote_plus(Binary) when is_binary(Binary) ->
       quote_plus(binary_to_list(Binary));
  +quote_plus(Float) when is_float(Float) ->
  +    quote_plus(mochinum:digits(Float));
   quote_plus(String) ->
       quote_plus(String, []).
   
  
positive.code: test_quote_plus() ->
      "foo" = quote_plus(foo),
      "1" = quote_plus(1),
      "foo" = quote_plus("foo"),
      "foo+bar" = quote_plus("foo bar"),
      "foo%0A" = quote_plus("foo\n"),
  
negative.code: revjoin([S | Rest], Separator, Acc) ->
      revjoin(Rest, Separator, [S, Separator | Acc]).
  
  %% @spec quote_plus(atom() | integer() | float() | string() | binary()) -> string()
  %% @doc URL safe encoding of the given term.
  quote_plus(Atom) when is_atom(Atom) ->
      quote_plus(atom_to_list(Atom));
  