langchain/libs/experimental/langchain_experimental/tot/memory.py
Vadim Gubergrits e7e5cb9d08
Tree of Thought introducing a new ToTChain. (#5167)
# [WIP] Tree of Thought introducing a new ToTChain.

This PR adds a new chain called ToTChain that implements the ["Large
Language Model Guided
Tree-of-Though"](https://arxiv.org/pdf/2305.08291.pdf) paper.

There's a notebook example `docs/modules/chains/examples/tot.ipynb` that
shows how to use it.


Implements #4975


## Who can review?

Community members can review the PR once tests pass. Tag
maintainers/contributors who might be interested:

- @hwchase17
- @vowelparrot

---------

Co-authored-by: Vadim Gubergrits <vgubergrits@outbox.com>
Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>
2023-07-26 21:29:39 -07:00

47 lines
1.4 KiB
Python

from __future__ import annotations
from typing import List, Optional
from langchain_experimental.tot.thought import Thought
class ToTDFSMemory:
"""
Memory for the Tree of Thought (ToT) chain. Implemented as a stack of
thoughts. This allows for a depth first search (DFS) of the ToT.
"""
def __init__(self, stack: Optional[List[Thought]] = None):
self.stack: list[Thought] = stack or []
def top(self) -> Optional[Thought]:
"Get the top of the stack without popping it."
return self.stack[-1] if len(self.stack) > 0 else None
def pop(self, n: int = 1) -> Optional[Thought]:
"Pop the top n elements of the stack and return the last one."
if len(self.stack) < n:
return None
for _ in range(n):
node = self.stack.pop()
return node
def top_parent(self) -> Optional[Thought]:
"Get the parent of the top of the stack without popping it."
return self.stack[-2] if len(self.stack) > 1 else None
def store(self, node: Thought) -> None:
"Add a node on the top of the stack."
if len(self.stack) > 0:
self.stack[-1].children.add(node)
self.stack.append(node)
@property
def level(self) -> int:
"Return the current level of the stack."
return len(self.stack)
def current_path(self) -> List[Thought]:
"Return the thoughts path."
return self.stack[:]