make multiple_input explicit

lm_eval/api/task.py

@@ -659,7 +659,7 @@ class ConfigurableTask(Task):
 
         # Test One Doc
         self.features: list[str] = list(self.task_docs.features.keys())
-        self.multiple_input = 0
+        self.multiple_input = self.config.multiple_input
         self.multiple_target = 0
         test_doc = self.task_docs[0]
         test_text = self.doc_to_text(test_doc)

lm_eval/config/task.py

@@ -166,6 +166,7 @@ class TaskConfig:
     should_decontaminate: bool = False
     doc_to_decontamination_query: str | None = None
     gen_prefix: str | None = None
+    multiple_input: bool = False
     metadata: dict | None = field(
         default_factory=dict
     )  # by default, not used in the code. allows for users to pass arbitrary info to tasks