Add falcon 180B chat conversation template

fastchat/conversation.py

@@ -27,6 +27,7 @@ class SeparatorStyle(IntEnum):
     RWKV = auto()
     PHOENIX = auto()
     ROBIN = auto()
+    FALCON_CHAT = auto()
 
 
 @dataclasses.dataclass
@@ -200,6 +201,22 @@ def get_prompt(self) -> str:
                 else:
                     ret += role + ":\n"
             return ret
+        elif self.sep_style == SeparatorStyle.FALCON_CHAT:
+            ret = ""
+            for idx, (role, message) in enumerate(self.messages):
+                if role == "System":
+                    assert (
+                        idx == 0
+                    ), f"System message must be the first message, but got {idx}-th message."
+                if message:
+                    ret += role + ": " + message + self.sep
+                else:
+                    assert (
+                        idx == len(self.messages) - 1
+                    ), f"Only the last message can be empty, but got {idx}-th message."
+                    ret += role + ": "
+
+            return ret
         else:
             raise ValueError(f"Invalid style: {self.sep_style}")
 
@@ -905,6 +922,19 @@ def get_conv_template(name: str) -> Conversation:
     )
 )
 
+# Falcon 180B chat template
+register_conv_template(
+    Conversation(
+        name="falcon-chat",
+        roles=("User", "Falcon", "System"),
+        messages=[],
+        sep_style=SeparatorStyle.FALCON_CHAT,
+        sep="\n",
+        sep2="<|endoftext|>",
+        stop_str="\nUser:",  # use stop_str to stop generation after stop_token_ids, it will also remove stop_str from the generated text
+    )
+)
+
 
 if __name__ == "__main__":
     print("Vicuna template:")