make OAI completions work with new generation kwargs format

lm_eval/models/openai_completions.py

@@ -194,7 +194,7 @@ class OpenaiCompletionsLM(LM):
                 yield ret, lastuntil
 
         # todo: more intelligent batching for heterogeneous `until`
-        for chunk, until in tqdm(
+        for chunk, request_args in tqdm(
             list(sameuntil_chunks(re_ord.get_reordered(), self.REQ_CHUNK_SIZE))
         ):
             inps = []
@@ -203,6 +203,13 @@ class OpenaiCompletionsLM(LM):
                 inp = context_enc[-(self.max_length - self.max_gen_toks) :]
                 inps.append(inp)
 
+            try:
+                until = request_args["until"][
+                    0
+                ]  # TODO: does this handle a list of stop seqs correctly?
+            except KeyError:
+                until = "<|endoftext|>"
+
             response = oa_completion(
                 engine=self.engine,
                 prompt=inps,
@@ -212,14 +219,19 @@ class OpenaiCompletionsLM(LM):
                 stop=until,
             )
 
-            for resp, (context, until_) in zip(response.choices, chunk):
+            for resp, (context, args_) in zip(response.choices, chunk):
                 s = resp["text"]
 
+                until_ = args_.get(["until"], [])
+
                 for term in until_:
-                    s = s.split(term)[0]
+                    if len(term) > 0:
+                        s = s.split(term)[0]
 
                 # partial caching
-                self.cache_hook.add_partial("greedy_until", (context, until_), s)
+                self.cache_hook.add_partial(
+                    "greedy_until", (context, {"until": until_}), s
+                )
 
                 res.append(s)