+
+t_map_result(_Cfg) ->
+ AssertPositive =
+ fun (I) when I > 0 -> {ok, I}; (_) -> {error, negative} end,
+ AllPositives = lists:seq(1, 5),
+ AllNegatives = lists:seq(-5, -1),
+ Mixed = lists:seq(-5, 5),
+ {ok, AllPositives} = hope_list:map_result(AllPositives, AssertPositive),
+ {error, negative} = hope_list:map_result(AllNegatives, AssertPositive),
+ {error, negative} = hope_list:map_result(Mixed, AssertPositive).