src/llamafactory/data/formatter.py

# Copyright 2024 the LlamaFactory team.
#
# 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 json
import re
from abc import ABC, abstractmethod
from dataclasses import dataclass, field
from typing import Any, Dict, List, Literal, Optional, Sequence, Set, Tuple, Union


SLOTS = Sequence[Union[str, Set[str], Dict[str, str]]]


JSON_FORMAT_PROMPT = (
    """, in a JSON format representing the kwargs (e.g. ```{"input": "hello world", "num_beams": 5}```)"""
)


TOOL_SYSTEM_PROMPT = (
    "You have access to the following tools:\n{tool_text}"
    "Use the following format if using a tool:\n"
    "```\n"
    "Action: tool name (one of [{tool_names}]).\n"
    "Action Input: the input to the tool{format_prompt}.\n"
    "```\n"
)


def default_tool_formatter(tools: List[Dict[str, Any]]) -> str:
    tool_text = ""
    tool_names = []
    for tool in tools:
        param_text = ""
        for name, param in tool["parameters"]["properties"].items():
            required = ", required" if name in tool["parameters"].get("required", []) else ""
            enum = ", should be one of [{}]".format(", ".join(param["enum"])) if param.get("enum", None) else ""
            items = (
                ", where each item should be {}".format(param["items"].get("type", "")) if param.get("items") else ""
            )
            param_text += "  - {name} ({type}{required}): {desc}{enum}{items}\n".format(
                name=name,
                type=param.get("type", ""),
                required=required,
                desc=param.get("description", ""),
                enum=enum,
                items=items,
            )

        tool_text += "> Tool Name: {name}\nTool Description: {desc}\nTool Args:\n{args}\n".format(
            name=tool["name"], desc=tool.get("description", ""), args=param_text
        )
        tool_names.append(tool["name"])

    return TOOL_SYSTEM_PROMPT.format(
        tool_text=tool_text, tool_names=", ".join(tool_names), format_prompt=JSON_FORMAT_PROMPT
    )


def default_tool_extractor(content: str) -> Union[str, Tuple[str, str]]:
    regex = re.compile(r"Action:\s*([a-zA-Z0-9_]+).*?Action Input:\s*(.*)", re.DOTALL)
    action_match = re.search(regex, content)
    if not action_match:
        return content

    tool_name = action_match.group(1).strip()
    tool_input = action_match.group(2).strip().strip('"').strip("```")
    try:
        arguments = json.loads(tool_input)
    except json.JSONDecodeError:
        return content

    return tool_name, json.dumps(arguments, ensure_ascii=False)


@dataclass
class Formatter(ABC):
    slots: SLOTS = field(default_factory=list)
    tool_format: Optional[Literal["default"]] = None

    @abstractmethod
    def apply(self, **kwargs) -> SLOTS: ...

    def extract(self, content: str) -> Union[str, Tuple[str, str]]:
        raise NotImplementedError


@dataclass
class EmptyFormatter(Formatter):
    def __post_init__(self):
        has_placeholder = False
        for slot in filter(lambda s: isinstance(s, str), self.slots):
            if re.search(r"\{\{[a-zA-Z_][a-zA-Z0-9_]*\}\}", slot):
                has_placeholder = True

        if has_placeholder:
            raise ValueError("Empty formatter should not contain any placeholder.")

    def apply(self, **kwargs) -> SLOTS:
        return self.slots


@dataclass
class StringFormatter(Formatter):
    def __post_init__(self):
        has_placeholder = False
        for slot in filter(lambda s: isinstance(s, str), self.slots):
            if re.search(r"\{\{[a-zA-Z_][a-zA-Z0-9_]*\}\}", slot):
                has_placeholder = True

        if not has_placeholder:
            raise ValueError("A placeholder is required in the string formatter.")

    def apply(self, **kwargs) -> SLOTS:
        elements = []
        for slot in self.slots:
            if isinstance(slot, str):
                for name, value in kwargs.items():
                    if not isinstance(value, str):
                        raise RuntimeError("Expected a string, got {}".format(value))

                    slot = slot.replace("{{" + name + "}}", value, 1)
                elements.append(slot)
            elif isinstance(slot, (dict, set)):
                elements.append(slot)
            else:
                raise RuntimeError("Input must be string, set[str] or dict[str, str], got {}".format(type(slot)))

        return elements


@dataclass
class FunctionFormatter(Formatter):
    def __post_init__(self):
        has_name, has_args = False, False
        for slot in filter(lambda s: isinstance(s, str), self.slots):
            if "{{name}}" in slot:
                has_name = True
            if "{{arguments}}" in slot:
                has_args = True

        if not has_name or not has_args:
            raise ValueError("Name and arguments placeholders are required in the function formatter.")

    def apply(self, **kwargs) -> SLOTS:
        content = kwargs.pop("content")
        try:
            function = json.loads(content)
            name = function["name"]
            arguments = json.dumps(function["arguments"], ensure_ascii=False)
        except Exception:
            name, arguments = "", ""

        elements = []
        for slot in self.slots:
            if isinstance(slot, str):
                slot = slot.replace("{{name}}", name).replace("{{arguments}}", arguments)
                elements.append(slot)
            elif isinstance(slot, (dict, set)):
                elements.append(slot)
            else:
                raise RuntimeError("Input must be string, set[str] or dict[str, str], got {}".format(type(slot)))

        return elements


@dataclass
class ToolFormatter(Formatter):
    def __post_init__(self):
        if self.tool_format is None:
            raise ValueError("Tool format was not found.")

    def apply(self, **kwargs) -> SLOTS:
        content = kwargs.pop("content")
        try:
            tools = json.loads(content)
            if not len(tools):
                return [""]

            if self.tool_format == "default":
                return [default_tool_formatter(tools)]
            else:
                raise NotImplementedError
        except Exception:
            return [""]

    def extract(self, content: str) -> Union[str, Tuple[str, str]]:
        if self.tool_format == "default":
            return default_tool_extractor(content)
        else:
            raise NotImplementedError