Remove Instruct/Chat versions of models & introduce a new ChatTemplate API, fix Anthropic API

.github/workflows/workflow-pr-gate.yml

@@ -134,6 +134,7 @@ jobs:
     needs:
       - unit-tests-linux-python-other
       - unit-tests-gpu-python-latest
+      - server-tests
     name: End Stage 2
     runs-on: ubuntu-latest
     steps:

.gitignore

@@ -22,4 +22,6 @@ guidance/_rust/Cargo.lock
 
 notebooks/**/*.papermill_out.ipynb
 
-.mypy_cache/*
+.mypy_cache/*
+
+**/scratch.*

README.md

@@ -55,8 +55,8 @@ else:
 ```python
 from guidance import user, assistant
 
-# load a chat model
-chat_lm = models.LlamaCppChat(path)
+# load a model
+chat_lm = models.LlamaCpp(path)
 
 # wrap with chat block contexts
 with user():

guidance/_chat.py

@@ -0,0 +1,210 @@
+import warnings
+import uuid
+import inspect
+
+class ChatTemplate:
+    """Contains template for all chat and instruct tuned models."""
+
+    def get_role_start(self, role_name, **kwargs):
+        raise NotImplementedError(
+            "You need to use a ChatTemplate subclass that overrides the get_role_start method"
+        )
+
+    def get_role_end(self, role_name=None):
+        raise NotImplementedError(
+            "You need to use a ChatTemplate subclass that overrides the get_role_start method"
+        )
+
+class ChatTemplateCache: 
+    def __init__(self):
+        self._cache = {}
+
+    def __getitem__(self, key):
+        key_compact = key.replace(" ", "")
+        return self._cache[key_compact]
+
+
+    def __setitem__(self, key, value):
+        key_compact = key.replace(" ", "")
+        self._cache[key_compact] = value
+
+    def __contains__(self, key):
+        key_compact = key.replace(" ", "")
+        return key_compact in self._cache
+
+# Feels weird having to instantiate this, but it's a singleton for all purposes
+# TODO [HN]: Add an alias system so we can instantiate with other simple keys (e.g. "llama2" instead of the full template string)
+CHAT_TEMPLATE_CACHE = ChatTemplateCache() 
+
+class UnsupportedRoleException(Exception):
+    def __init__(self, role_name, instance):
+        self.role_name = role_name
+        self.instance = instance
+        super().__init__(self._format_message())
+
+    def _format_message(self):
+        return (f"Role {self.role_name} is not supported by the {self.instance.__class__.__name__} chat template. ")
+
+def load_template_class(chat_template=None):
+    """Utility method to find the best chat template.
+
+    Order of precedence:
+    - If it's a chat template class, use it directly
+    - If it's a string, check the cache of popular model templates
+    - If it's a string and not in the cache, try to create a class dynamically
+    - [TODO] If it's a string and can't be created, default to ChatML and raise a warning
+    - If it's None, default to ChatML and raise a warning
+    """
+    if inspect.isclass(chat_template) and issubclass(chat_template, ChatTemplate):
+        if chat_template is ChatTemplate:
+            raise Exception("You can't use the base ChatTemplate class directly. Create or use a subclass instead.")
+        return chat_template
+
+    elif isinstance(chat_template, str):
+        # First check the cache of popular model types
+        # TODO: Expand keys of cache to include aliases for popular model types (e.g. "llama2, phi3")
+        # Can possibly accomplish this with an "aliases" dictionary that maps all aliases to the canonical key in cache
+        if chat_template in CHAT_TEMPLATE_CACHE:
+            return CHAT_TEMPLATE_CACHE[chat_template]
+        # TODO: Add logic here to try to auto-create class dynamically via _template_class_from_string method
+
+    # Only warn when a user provided a chat template that we couldn't load
+    if chat_template is not None:
+        warnings.warn(f"""Chat template {chat_template} was unable to be loaded directly into guidance.
+                        Defaulting to the ChatML format which may not be optimal for the selected model. 
+                        For best results, create and pass in a `guidance.ChatTemplate` subclass for your model.""")
+
+    # By default, use the ChatML Template. Warnings to user will happen downstream only if they use chat roles.
+    return ChatMLTemplate
+
+
+def _template_class_from_string(template_str):
+    """Utility method to try to create a chat template class from a string."""
+    # TODO: Try to build this, perhaps based on passing unit tests we create?
+    pass
+
+
+# CACHE IMPLEMENTATIONS:
+
+# --------------------------------------------------
+# @@@@ ChatML @@@@
+# --------------------------------------------------
+# Note that all grammarless models will default to this syntax, since we typically send chat formatted messages.
+chatml_template = "{% for message in messages %}{{'<|im_start|>' + message['role'] + '\n' + message['content'] + '<|im_end|>' + '\n'}}{% endfor %}"
+class ChatMLTemplate(ChatTemplate):
+    template_str = chatml_template
+
+    def get_role_start(self, role_name):
+        return f"<|im_start|>{role_name}\n"
+
+    def get_role_end(self, role_name=None):
+        return "<|im_end|>\n"
+
+CHAT_TEMPLATE_CACHE[chatml_template] = ChatMLTemplate
+
+
+# --------------------------------------------------
+# @@@@ Llama-2 @@@@
+# --------------------------------------------------
+# [05/08/24] https://huggingface.co/meta-llama/Llama-2-7b-chat-hf/blob/main/tokenizer_config.json#L12
+llama2_template = "{% if messages[0]['role'] == 'system' %}{% set loop_messages = messages[1:] %}{% set system_message = messages[0]['content'] %}{% else %}{% set loop_messages = messages %}{% set system_message = false %}{% endif %}{% for message in loop_messages %}{% if (message['role'] == 'user') != (loop.index0 % 2 == 0) %}{{ raise_exception('Conversation roles must alternate user/assistant/user/assistant/...') }}{% endif %}{% if loop.index0 == 0 and system_message != false %}{% set content = '<<SYS>>\\n' + system_message + '\\n<</SYS>>\\n\\n' + message['content'] %}{% else %}{% set content = message['content'] %}{% endif %}{% if message['role'] == 'user' %}{{ bos_token + '[INST] ' + content.strip() + ' [/INST]' }}{% elif message['role'] == 'assistant' %}{{ ' '  + content.strip() + ' ' + eos_token }}{% endif %}{% endfor %}"
+class Llama2ChatTemplate(ChatTemplate):
+    # available_roles = ["system", "user", "assistant"]
+    template_str = llama2_template
+
+    def get_role_start(self, role_name):
+        if role_name == "system":
+            return "[INST] <<SYS>>\n"
+        elif role_name == "user":
+            return "<s>[INST]"
+        elif role_name == "assistant":
+            return " "
+        else:
+            raise UnsupportedRoleException(role_name, self)
+
+    def get_role_end(self, role_name=None):
+        if role_name == "system":
+            return "\n<</SYS>"
+        elif role_name == "user":
+            return " [/INST]"
+        elif role_name == "assistant":
+            return "</s>"
+        else:
+            raise UnsupportedRoleException(role_name, self)
+
+CHAT_TEMPLATE_CACHE[llama2_template] = Llama2ChatTemplate
+
+
+# --------------------------------------------------
+# @@@@ Llama-3 @@@@
+# --------------------------------------------------
+# [05/08/24] https://huggingface.co/meta-llama/Meta-Llama-3-8B-Instruct/blob/main/tokenizer_config.json#L2053
+llama3_template = "{% set loop_messages = messages %}{% for message in loop_messages %}{% set content = '<|start_header_id|>' + message['role'] + '<|end_header_id|>\n\n'+ message['content'] | trim + '<|eot_id|>' %}{% if loop.index0 == 0 %}{% set content = bos_token + content %}{% endif %}{{ content }}{% endfor %}{% if add_generation_prompt %}{{ '<|start_header_id|>assistant<|end_header_id|>\n\n' }}{% endif %}"
+class Llama3ChatTemplate(ChatTemplate):
+    # available_roles = ["system", "user", "assistant"]
+    template_str = llama3_template
+
+    def get_role_start(self, role_name):
+        if role_name == "system":
+            return "<|begin_of_text|><|start_header_id|>system<|end_header_id|>\n\n"
+        elif role_name == "user":
+            return "<|start_header_id|>user<|end_header_id>\n\n"
+        elif role_name == "assistant":
+            return "<|start_header_id|>assistant<|end_header_id>\n\n"
+        else:
+            raise UnsupportedRoleException(role_name, self)
+
+    def get_role_end(self, role_name=None):
+        return "<|eot_id|>"
+
+CHAT_TEMPLATE_CACHE[llama3_template] = Llama3ChatTemplate
+
+# --------------------------------------------------
+# @@@@ Phi-3 @@@@
+# --------------------------------------------------
+# [05/08/24] https://huggingface.co/microsoft/Phi-3-mini-4k-instruct/blob/main/tokenizer_config.json#L119
+phi3_template = "{{ bos_token }}{% for message in messages %}{% if (message['role'] == 'user') %}{{'<|user|>' + '\n' + message['content'] + '<|end|>' + '\n' + '<|assistant|>' + '\n'}}{% elif (message['role'] == 'assistant') %}{{message['content'] + '<|end|>' + '\n'}}{% endif %}{% endfor %}"
+class Phi3ChatTemplate(ChatTemplate):
+    # available_roles = ["user", "assistant"]
+    template_str = phi3_template
+
+    def get_role_start(self, role_name):
+        if role_name == "user":
+            return "<|user|>"
+        elif role_name == "assistant":
+            return "<|assistant|>"
+        else:
+            raise UnsupportedRoleException(role_name, self)
+
+    def get_role_end(self, role_name=None):
+        return "<|end|>"
+
+CHAT_TEMPLATE_CACHE[phi3_template] = Phi3ChatTemplate
+
+
+# --------------------------------------------------
+# @@@@ Mistral-7B-Instruct-v0.2 @@@@
+# --------------------------------------------------
+# [05/08/24] https://huggingface.co/mistralai/Mistral-7B-Instruct-v0.2/blob/main/tokenizer_config.json#L42
+mistral_7b_instruct_template = "{{ bos_token }}{% for message in messages %}{% if (message['role'] == 'user') != (loop.index0 % 2 == 0) %}{{ raise_exception('Conversation roles must alternate user/assistant/user/assistant/...') }}{% endif %}{% if message['role'] == 'user' %}{{ '[INST] ' + message['content'] + ' [/INST]' }}{% elif message['role'] == 'assistant' %}{{ message['content'] + eos_token}}{% else %}{{ raise_exception('Only user and assistant roles are supported!') }}{% endif %}{% endfor %}"
+class Mistral7BInstructChatTemplate(ChatTemplate):
+    # available_roles = ["user", "assistant"]
+    template_str = mistral_7b_instruct_template
+
+    def get_role_start(self, role_name):
+        if role_name == "user":
+            return "[INST] "
+        elif role_name == "assistant":
+            return ""
+        else:
+            raise UnsupportedRoleException(role_name, self)
+
+    def get_role_end(self, role_name=None):
+        if role_name == "user":
+            return " [/INST]"
+        elif role_name == "assistant":
+            return "</s>"
+        else:
+            raise UnsupportedRoleException(role_name, self)
+
+CHAT_TEMPLATE_CACHE[mistral_7b_instruct_template] = Mistral7BInstructChatTemplate

guidance/library/_role.py

@@ -7,14 +7,10 @@
 span_start = "<||_html:<span style='background-color: rgba(255, 180, 0, 0.3); border-radius: 3px;'>_||>"
 span_end = "<||_html:</span>_||>"
 
-
 @guidance
 def role_opener(lm, role_name, **kwargs):
     indent = getattr(lm, "indent_roles", True)
-    if not hasattr(lm, "get_role_start"):
-        raise Exception(
-            f"You need to use a chat model in order the use role blocks like `with {role_name}():`! Perhaps you meant to use the {type(lm).__name__}Chat class?"
-        )
+
 
     # Block start container (centers elements)
     if indent:
@@ -25,8 +21,17 @@ def role_opener(lm, role_name, **kwargs):
         lm += nodisp_start
     else:
         lm += span_start
-
-    lm += lm.get_role_start(role_name, **kwargs)
+
+    # TODO [HN]: Temporary change while I instrument chat_template in transformers only.
+    # Eventually have all models use chat_template.
+    if hasattr(lm, "get_role_start"):
+        lm += lm.get_role_start(role_name, **kwargs)
+    elif hasattr(lm, "chat_template"):
+        lm += lm.chat_template.get_role_start(role_name)
+    else:
+        raise Exception(
+            f"You need to use a chat model in order the use role blocks like `with {role_name}():`! Perhaps you meant to use the {type(lm).__name__}Chat class?"
+        )
 
     # End of either debug or HTML no disp block
     if indent:
@@ -46,7 +51,12 @@ def role_closer(lm, role_name, **kwargs):
     else:
         lm += span_start
 
-    lm += lm.get_role_end(role_name)
+    # TODO [HN]: Temporary change while I instrument chat_template in transformers only.
+    # Eventually have all models use chat_template.
+    if hasattr(lm, "get_role_end"):
+        lm += lm.get_role_end(role_name)
+    elif hasattr(lm, "chat_template"):
+        lm += lm.chat_template.get_role_end(role_name)
 
     # End of either debug or HTML no disp block
     if indent:
@@ -60,7 +70,7 @@ def role_closer(lm, role_name, **kwargs):
 
     return lm
 
-
+# TODO HN: Add a docstring to better describe arbitrary role functions
 def role(role_name, text=None, **kwargs):
     if text is None:
         return block(

guidance/models/__init__.py

@@ -1,8 +1,8 @@
 from ._model import Model, Instruct, Chat
 
 # local models
-from .transformers._transformers import Transformers, TransformersChat
-from .llama_cpp import LlamaCpp, LlamaCppChat, MistralInstruct, MistralChat
+from .transformers._transformers import Transformers
+from .llama_cpp import LlamaCpp
 from ._mock import Mock, MockChat
 
 # grammarless models (we can't do constrained decoding for them)
@@ -15,15 +15,12 @@
 )
 from ._azure_openai import (
     AzureOpenAI,
-    AzureOpenAIChat,
-    AzureOpenAICompletion,
-    AzureOpenAIInstruct,
 )
 from ._azureai_studio import AzureAIStudioChat
-from ._openai import OpenAI, OpenAIChat, OpenAIInstruct, OpenAICompletion
+from ._openai import OpenAI
 from ._lite_llm import LiteLLM, LiteLLMChat, LiteLLMInstruct, LiteLLMCompletion
 from ._cohere import Cohere, CohereCompletion, CohereInstruct
-from ._anthropic import Anthropic, AnthropicChat
+from ._anthropic import Anthropic
 from ._googleai import GoogleAI, GoogleAIChat
 from ._togetherai import (
     TogetherAI,