Files
petya 75601988c2 Initial commit: LangChain evolution tutorial deck (132 slides)
- Cover, TOC, 5 dividers, 3 recap slides
- 5 sections (chains, langgraph, deepagents, openswe, ecosystem)
- design-system.js with theme tokens + 9 helper functions
- research/: timeline + sources + per-tech notes
- final-compile.js + merge.js for rebuild pipeline
- output/: langchain-evolution.pptx (2.3 MB) + langchain-evolution.pdf (1.1 MB) + 7 sample previews
2026-06-22 11:29:03 +03:00

62 lines
2.3 KiB
JavaScript

// Slide 18: Retrievers + Vector Stores -- FAISS / Chroma / PGVector
// Code slide: index documents, embed, retrieve top-k, plug into a chain.
const ds = require('./design-system');
function createSlide(pres, theme) {
const slide = pres.addSlide();
ds.helpers.slideBase(slide, pres, theme);
ds.helpers.addHeader(slide, pres, theme, {
eyebrow: 'STAGE 1: CHAINS',
section: 'Retrievers',
title: 'Vector store -> retriever -> RAG-цепочка',
sectionNumber: 1,
});
ds.helpers.addCodeBlock(slide, pres, theme, {
x: 0.5, y: 1.5, w: 9.0, h: 3.25,
language: 'python',
filePath: 'examples/retriever_rag.py',
code: [
'from langchain_openai import OpenAIEmbeddings',
'from langchain_community.vectorstores import FAISS',
'from langchain_core.runnables import RunnablePassthrough',
'',
'# 1. Эмбеддинги и индекс',
'embeddings = OpenAIEmbeddings(model="text-embedding-3-small")',
'docs = ["Cats are mammals.", "Python is a programming language.",',
' "LangChain helps build LLM apps."]',
'vectorstore = FAISS.from_texts(docs, embedding=embeddings)',
'',
'# 2. .as_retriever() превращает store в Runnable',
'retriever = vectorstore.as_retriever(search_kwargs={"k": 2})',
'',
'# 3. RAG-цепочка через LCEL: context + question -> answer',
'from langchain_core.prompts import ChatPromptTemplate',
'from langchain.chat_models import init_chat_model',
'',
'prompt = ChatPromptTemplate.from_template(',
' "Answer based on context.\\nContext: {context}\\nQ: {question}"',
')',
'model = init_chat_model("openai:gpt-4.1-mini")',
'rag = (',
' {"context": retriever, "question": RunnablePassthrough()}',
' | prompt | model | StrOutputParser()',
')',
].join('\n'),
});
ds.helpers.addCallout(slide, pres, theme, {
x: 0.5, y: 4.85, w: 9.0, h: 0.3,
kind: 'info',
text: 'Альтернативные сторы: Chroma (легковесный), PGVector (production Postgres), Pinecone, Weaviate, Qdrant.',
});
ds.helpers.addSourceLine(slide, pres, theme, {
source: 'python.langchain.com/docs/concepts/retrievers/',
});
ds.helpers.addPageNumber(slide, pres, theme, 18);
}
module.exports = { createSlide };