127 lines
4.3 KiB
JavaScript
127 lines
4.3 KiB
JavaScript
"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.RetrievalQAChain = void 0;
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const base_js_1 = require("./base.cjs");
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const load_js_1 = require("./question_answering/load.cjs");
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/**
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* @deprecated This class will be removed in 1.0.0. See below for an example implementation using
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* `createRetrievalChain`:
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* Class representing a chain for performing question-answering tasks with
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* a retrieval component.
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* @example
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* ```typescript
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* import { createStuffDocumentsChain } from "langchain/chains/combine_documents";
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* import { ChatPromptTemplate } from "@langchain/core/prompts";
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* import { createRetrievalChain } from "langchain/chains/retrieval";
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* import { MemoryVectorStore } from "langchain/vectorstores/memory";
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*
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* const documents = [...your documents here];
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* const embeddings = ...your embeddings model;
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* const llm = ...your LLM model;
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*
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* const vectorstore = await MemoryVectorStore.fromDocuments(
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* documents,
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* embeddings
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* );
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* const prompt = ChatPromptTemplate.fromTemplate(`Answer the user's question: {input} based on the following context {context}`);
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*
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* const combineDocsChain = await createStuffDocumentsChain({
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* llm,
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* prompt,
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* });
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* const retriever = vectorstore.asRetriever();
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*
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* const retrievalChain = await createRetrievalChain({
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* combineDocsChain,
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* retriever,
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* });
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* ```
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*/
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class RetrievalQAChain extends base_js_1.BaseChain {
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static lc_name() {
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return "RetrievalQAChain";
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}
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get inputKeys() {
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return [this.inputKey];
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}
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get outputKeys() {
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return this.combineDocumentsChain.outputKeys.concat(this.returnSourceDocuments ? ["sourceDocuments"] : []);
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}
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constructor(fields) {
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super(fields);
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Object.defineProperty(this, "inputKey", {
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enumerable: true,
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configurable: true,
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writable: true,
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value: "query"
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});
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Object.defineProperty(this, "retriever", {
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enumerable: true,
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configurable: true,
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writable: true,
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value: void 0
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});
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Object.defineProperty(this, "combineDocumentsChain", {
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enumerable: true,
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configurable: true,
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writable: true,
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value: void 0
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});
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Object.defineProperty(this, "returnSourceDocuments", {
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enumerable: true,
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configurable: true,
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writable: true,
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value: false
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});
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this.retriever = fields.retriever;
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this.combineDocumentsChain = fields.combineDocumentsChain;
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this.inputKey = fields.inputKey ?? this.inputKey;
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this.returnSourceDocuments =
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fields.returnSourceDocuments ?? this.returnSourceDocuments;
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}
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/** @ignore */
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async _call(values, runManager) {
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if (!(this.inputKey in values)) {
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throw new Error(`Question key "${this.inputKey}" not found.`);
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}
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const question = values[this.inputKey];
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const docs = await this.retriever.getRelevantDocuments(question, runManager?.getChild("retriever"));
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const inputs = { question, input_documents: docs, ...values };
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const result = await this.combineDocumentsChain.call(inputs, runManager?.getChild("combine_documents"));
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if (this.returnSourceDocuments) {
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return {
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...result,
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sourceDocuments: docs,
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};
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}
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return result;
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}
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_chainType() {
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return "retrieval_qa";
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}
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static async deserialize(_data, _values) {
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throw new Error("Not implemented");
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}
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serialize() {
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throw new Error("Not implemented");
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}
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/**
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* Creates a new instance of RetrievalQAChain using a BaseLanguageModel
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* and a BaseRetriever.
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* @param llm The BaseLanguageModel used to generate a new question.
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* @param retriever The BaseRetriever used to retrieve relevant documents.
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* @param options Optional parameters for the RetrievalQAChain.
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* @returns A new instance of RetrievalQAChain.
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*/
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static fromLLM(llm, retriever, options) {
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const qaChain = (0, load_js_1.loadQAStuffChain)(llm, {
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prompt: options?.prompt,
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});
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return new this({
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...options,
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retriever,
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combineDocumentsChain: qaChain,
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});
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}
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}
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exports.RetrievalQAChain = RetrievalQAChain;
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