[erlang-bugs] Problem with nested opaque types

Jesper Larsson <>
Fri Oct 19 13:10:05 CEST 2012

On Oct 18, 2012, at 23:07, Kostis Sagonas wrote:
> Yes, I would call this a bug. We are aware that there are still issues with opaque datatypes -- note that they are not documented and this is for a reason. But we will investigate this nonetheless.

Thanks, I had no idea opaques were "not documented". This doesn't count as documentation, then? http://www.erlang.org/doc/reference_manual/typespec.html

> PS. Another way of shutting off the warnings (though I am not sure why) is to define the spec in module exporter as:
>  -spec traverser(exporter:tree()) -> exporter:trav().

In the more complex real situation where I encountered the problem, this trick reduced the number of Dialyzer errors, but I couldn't get them to completely go away no matter how many "exporter:" I put in.


More information about the erlang-bugs mailing list