[Feature] Support LLaMA-3 CPT and ST (#5619)

* support LLaMA-3

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Run pre-commit

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

applications/Colossal-LLaMA/colossal_llama/dataset/conversation.py

@@ -0,0 +1,106 @@
+#    Copyright 2023 lm-sys@FastChat
+#
+#    Licensed under the Apache License, Version 2.0 (the "License");
+#    you may not use this file except in compliance with the License.
+#    You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#    See the License for the specific language governing permissions and
+#    limitations under the License.
+
+import dataclasses
+from enum import Enum, auto
+from typing import List
+
+
+class SeparatorStyle(Enum):
+    ADD_BOS_EOS_TOKEN = auto()
+
+
+@dataclasses.dataclass
+class Conversation:
+    system: str
+    roles: List[str]
+    messages: List[List[str]]
+    offset: int
+    sep_style: SeparatorStyle
+    seps: List[str]
+
+    def clear(self):
+        self.messages = []
+
+    def get_prompt(self, length: int = None):
+        if length is None:
+            length = len(self.messages)
+
+        if self.sep_style == SeparatorStyle.ADD_BOS_EOS_TOKEN:
+            ret = self.system
+            for role, message in self.messages[0:length]:
+                if message:
+                    ret += role + ": " + self.seps[0] + message + self.seps[1]
+                else:
+                    ret += role + ": " + self.seps[0]
+            return ret
+        else:
+            raise ValueError(f"Invalid style: {self.sep_style}")
+
+    def save_prompt(self):
+        if self.sep_style == SeparatorStyle.ADD_BOS_EOS_TOKEN:
+            ret = self.system
+            for role, message in self.messages:
+                if message:
+                    ret += role + ": " + self.seps[0] + message + self.seps[1] + "\n"
+                else:
+                    ret += role + ": " + self.seps[0]
+            return ret
+        else:
+            raise ValueError(f"Invalid style: {self.sep_style}")
+
+    def append_message(self, role, message):
+        self.messages.append([role, message])
+
+    def copy(self):
+        return Conversation(
+            system=self.system,
+            roles=self.roles,
+            messages=[[x, y] for x, y in self.messages],
+            offset=self.offset,
+            sep_style=self.sep_style,
+            seps=self.seps,
+        )
+
+    def dict(self):
+        return {
+            "system": self.system,
+            "roles": self.roles,
+            "messages": self.messages,
+            "offset": self.offset,
+            "seps": self.seps,
+        }
+
+
+LLaMA2_Conv = Conversation(
+    system="A chat between a curious human and an artificial intelligence assistant. "
+    "The assistant gives helpful, detailed, and polite answers to the human's questions.\n\n",
+    roles=("Human", "Assistant"),
+    messages=[],
+    offset=0,
+    sep_style=SeparatorStyle.ADD_BOS_EOS_TOKEN,
+    seps=["<s>", "</s>"],
+)
+
+LLaMA3_Conv = Conversation(
+    system="A chat between a curious human and an artificial intelligence assistant. "
+    "The assistant gives helpful, detailed, and polite answers to the human's questions.\n\n",
+    roles=("Human", "Assistant"),
+    messages=[],
+    offset=0,
+    sep_style=SeparatorStyle.ADD_BOS_EOS_TOKEN,
+    seps=["<|begin_of_text|>", "<|end_of_text|>"],
+)
+
+default_conversation = LLaMA3_Conv