FunctionClauseError for a parameterized type referencing another parameterized type

[nicholasjhenry]

Should Hammox support parameterized union type consisting of custom types?

defmodule Result do
  @type ok(any) :: {:ok, any}
  @type error(any) :: {:error, any}

  @typedoc "the two-track type"
  @type t(a, b) :: ok(a) | error(b)
end

I get the following error:

     ** (FunctionClauseError) no function clause matching in Hammox.TypeEngine.match_type/2

     The following arguments were given to Hammox.TypeEngine.match_type/2:

         # 1
         :foo

         # 2
         {:var, 7, :a}

     Attempted function clauses (showing 10 out of 91):

         def match_type(value, {:type, _, :union, union_types} = union) when is_list(union_types)
         def match_type(_value, {:type, _, :any, []})
         def match_type(value, {:type, _, :none, []} = type)
         def match_type(value, {:type, _, :atom, []}) when is_atom(value)
         def match_type(value, {:type, _, :atom, []} = type)
         def match_type(value, {:type, _, :map, :any}) when is_map(value)
         def match_type(value, {:type, _, :pid, []}) when is_pid(value)
         def match_type(value, {:type, _, :pid, []} = type)
         def match_type(value, {:type, _, :port, []}) when is_port(value)
         def match_type(value, {:type, _, :port, []} = type)

     code: HammoxPlayground.Mock.perform(Decimal.new("0.992"))
     stacktrace:
       (hammox) lib/hammox/type_engine.ex:6: Hammox.TypeEngine.match_type/2
       (hammox) lib/hammox/type_engine.ex:100: anonymous fn/1 in Hammox.TypeEngine.match_type/2
       (elixir) lib/enum.ex:2984: Enum.find_value_list/3
       (hammox) lib/hammox/type_engine.ex:99: Hammox.TypeEngine.match_type/2
       (hammox) lib/hammox/type_engine.ex:9: anonymous fn/3 in Hammox.TypeEngine.match_type/2
       (elixir) lib/enum.ex:3325: Enumerable.List.reduce/3
       (elixir) lib/enum.ex:1998: Enum.reduce_while/3
       (hammox) lib/hammox/type_engine.ex:8: Hammox.TypeEngine.match_type/2
       (hammox) lib/hammox.ex:312: Hammox.match_return_value/2
       (hammox) lib/hammox.ex:280: Hammox.match_call/3
       (hammox) lib/hammox.ex:264: anonymous fn/4 in Hammox.check_call/3
       (elixir) lib/enum.ex:3325: Enumerable.List.reduce/3
       (elixir) lib/enum.ex:1998: Enum.reduce_while/3
       (hammox) lib/hammox.ex:263: Hammox.check_call/3
       (hammox) lib/hammox.ex:256: Hammox.protected_code/3
       test/hammox_playground_test.exs:13: (test)

[nicholasjhenry]

@msz Actually it's simpler than the original issue I posted. I've updated the title to refect this. This is the example that causes the exception:

  defmodule Result do
    @type ok(any) :: any
    @type t(a) :: ok(a)
  end