fix small TaskConfig bugs

lm_eval/api/task.py

@@ -98,13 +98,16 @@ class TaskConfig(dict):
             if type(self.gold_alias) == str:
                 self.gold_alias = self.template_aliases + self.gold_alias
 
-        if self.generation_kwargs or self.output_type == "greedy_until":
+        if self.generation_kwargs:
             assert (
                 self.output_type == "greedy_until"
             ), "passed `generation_kwargs`, but not using a generation request type!"
+        elif self.output_type == "greedy_until":    
             # ensure that we greedily generate in absence of explicit arguments otherwise
             self.generation_kwargs = {"do_sample": False, "temperature": 0.0}
 
+        # TODO: how to make TaskConfigs be de- and re-serializable, even when using the !function constructor?
+
     def __getitem__(self, item):
         return getattr(self, item)
 
@@ -123,6 +126,9 @@ class TaskConfig(dict):
         for k, v in list(cfg_dict.items()):
             if v is None:
                 cfg_dict.pop(k)
+            elif isinstance(v, Callable):
+                # TODO: this should handle Promptsource template objects as a separate case?
+                cfg_dict[k] = str(v)
         return cfg_dict
 
 
@@ -877,7 +883,7 @@ class ConfigurableTask(Task):
 
             for key, result in zip(self._metric_fn_list.keys(), results):
                 _dict = self._metric_fn_list[key].compute(
-                    references=[gold], predictions=[result], **self._metric_kwargs[key]
+                    references=[gold], predictions=[result], **self._metric_fn_kwargs[key]
                 )
 
                 result_dict = {**result_dict, **_dict}