agsamantha/node_modules/langchain/dist/chains/sequential_chain.cjs

324 lines
12 KiB
JavaScript
Raw Normal View History

2024-10-02 15:15:21 -05:00
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.SimpleSequentialChain = exports.SequentialChain = void 0;
const base_js_1 = require("./base.cjs");
const set_js_1 = require("../util/set.cjs");
function formatSet(input) {
return Array.from(input)
.map((i) => `"${i}"`)
.join(", ");
}
/**
* Chain where the outputs of one chain feed directly into next.
* @example
* ```typescript
* const promptTemplate = new PromptTemplate({
* template: `You are a playwright. Given the title of play and the era it is set in, it is your job to write a synopsis for that title.
* Title: {title}
* Era: {era}
* Playwright: This is a synopsis for the above play:`,
* inputVariables: ["title", "era"],
* });
* const reviewPromptTemplate = new PromptTemplate({
* template: `You are a play critic from the New York Times. Given the synopsis of play, it is your job to write a review for that play.
*
* Play Synopsis:
* {synopsis}
* Review from a New York Times play critic of the above play:`,
* inputVariables: ["synopsis"],
* });
* const overallChain = new SequentialChain({
* chains: [
* new LLMChain({
* llm: new ChatOpenAI({ temperature: 0 }),
* prompt: promptTemplate,
* outputKey: "synopsis",
* }),
* new LLMChain({
* llm: new OpenAI({ temperature: 0 }),
* prompt: reviewPromptTemplate,
* outputKey: "review",
* }),
* ],
* inputVariables: ["era", "title"],
* outputVariables: ["synopsis", "review"],
* verbose: true,
* });
* const chainExecutionResult = await overallChain.call({
* title: "Tragedy at sunset on the beach",
* era: "Victorian England",
* });
* console.log(chainExecutionResult);
* ```
*
* @deprecated
* Switch to {@link https://js.langchain.com/docs/expression_language/ | expression language}.
* Will be removed in 0.2.0
*/
class SequentialChain extends base_js_1.BaseChain {
static lc_name() {
return "SequentialChain";
}
get inputKeys() {
return this.inputVariables;
}
get outputKeys() {
return this.outputVariables;
}
constructor(fields) {
super(fields);
Object.defineProperty(this, "chains", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "inputVariables", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "outputVariables", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "returnAll", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
this.chains = fields.chains;
this.inputVariables = fields.inputVariables;
this.outputVariables = fields.outputVariables ?? [];
if (this.outputVariables.length > 0 && fields.returnAll) {
throw new Error("Either specify variables to return using `outputVariables` or use `returnAll` param. Cannot apply both conditions at the same time.");
}
this.returnAll = fields.returnAll ?? false;
this._validateChains();
}
/** @ignore */
_validateChains() {
if (this.chains.length === 0) {
throw new Error("Sequential chain must have at least one chain.");
}
const memoryKeys = this.memory?.memoryKeys ?? [];
const inputKeysSet = new Set(this.inputKeys);
const memoryKeysSet = new Set(memoryKeys);
const keysIntersection = (0, set_js_1.intersection)(inputKeysSet, memoryKeysSet);
if (keysIntersection.size > 0) {
throw new Error(`The following keys: ${formatSet(keysIntersection)} are overlapping between memory and input keys of the chain variables. This can lead to unexpected behaviour. Please use input and memory keys that don't overlap.`);
}
const availableKeys = (0, set_js_1.union)(inputKeysSet, memoryKeysSet);
for (const chain of this.chains) {
let missingKeys = (0, set_js_1.difference)(new Set(chain.inputKeys), availableKeys);
if (chain.memory) {
missingKeys = (0, set_js_1.difference)(missingKeys, new Set(chain.memory.memoryKeys));
}
if (missingKeys.size > 0) {
throw new Error(`Missing variables for chain "${chain._chainType()}": ${formatSet(missingKeys)}. Only got the following variables: ${formatSet(availableKeys)}.`);
}
const outputKeysSet = new Set(chain.outputKeys);
const overlappingOutputKeys = (0, set_js_1.intersection)(availableKeys, outputKeysSet);
if (overlappingOutputKeys.size > 0) {
throw new Error(`The following output variables for chain "${chain._chainType()}" are overlapping: ${formatSet(overlappingOutputKeys)}. This can lead to unexpected behaviour.`);
}
for (const outputKey of outputKeysSet) {
availableKeys.add(outputKey);
}
}
if (this.outputVariables.length === 0) {
if (this.returnAll) {
const outputKeys = (0, set_js_1.difference)(availableKeys, inputKeysSet);
this.outputVariables = Array.from(outputKeys);
}
else {
this.outputVariables = this.chains[this.chains.length - 1].outputKeys;
}
}
else {
const missingKeys = (0, set_js_1.difference)(new Set(this.outputVariables), new Set(availableKeys));
if (missingKeys.size > 0) {
throw new Error(`The following output variables were expected to be in the final chain output but were not found: ${formatSet(missingKeys)}.`);
}
}
}
/** @ignore */
async _call(values, runManager) {
let input = {};
const allChainValues = values;
let i = 0;
for (const chain of this.chains) {
i += 1;
input = await chain.call(allChainValues, runManager?.getChild(`step_${i}`));
for (const key of Object.keys(input)) {
allChainValues[key] = input[key];
}
}
const output = {};
for (const key of this.outputVariables) {
output[key] = allChainValues[key];
}
return output;
}
_chainType() {
return "sequential_chain";
}
static async deserialize(data) {
const chains = [];
const inputVariables = data.input_variables;
const outputVariables = data.output_variables;
const serializedChains = data.chains;
for (const serializedChain of serializedChains) {
const deserializedChain = await base_js_1.BaseChain.deserialize(serializedChain);
chains.push(deserializedChain);
}
return new SequentialChain({ chains, inputVariables, outputVariables });
}
serialize() {
const chains = [];
for (const chain of this.chains) {
chains.push(chain.serialize());
}
return {
_type: this._chainType(),
input_variables: this.inputVariables,
output_variables: this.outputVariables,
chains,
};
}
}
exports.SequentialChain = SequentialChain;
/**
* @deprecated Switch to expression language: https://js.langchain.com/docs/expression_language/
* Simple chain where a single string output of one chain is fed directly into the next.
* @augments BaseChain
* @augments SimpleSequentialChainInput
*
* @example
* ```ts
* import { SimpleSequentialChain, LLMChain } from "langchain/chains";
* import { OpenAI } from "langchain/llms/openai";
* import { PromptTemplate } from "langchain/prompts";
*
* // This is an LLMChain to write a synopsis given a title of a play.
* const llm = new OpenAI({ temperature: 0 });
* const template = `You are a playwright. Given the title of play, it is your job to write a synopsis for that title.
*
* Title: {title}
* Playwright: This is a synopsis for the above play:`
* const promptTemplate = new PromptTemplate({ template, inputVariables: ["title"] });
* const synopsisChain = new LLMChain({ llm, prompt: promptTemplate });
*
*
* // This is an LLMChain to write a review of a play given a synopsis.
* const reviewLLM = new OpenAI({ temperature: 0 })
* const reviewTemplate = `You are a play critic from the New York Times. Given the synopsis of play, it is your job to write a review for that play.
*
* Play Synopsis:
* {synopsis}
* Review from a New York Times play critic of the above play:`
* const reviewPromptTemplate = new PromptTemplate({ template: reviewTemplate, inputVariables: ["synopsis"] });
* const reviewChain = new LLMChain({ llm: reviewLLM, prompt: reviewPromptTemplate });
*
* const overallChain = new SimpleSequentialChain({chains: [synopsisChain, reviewChain], verbose:true})
* const review = await overallChain.run("Tragedy at sunset on the beach")
* // the variable review contains resulting play review.
* ```
*/
class SimpleSequentialChain extends base_js_1.BaseChain {
static lc_name() {
return "SimpleSequentialChain";
}
get inputKeys() {
return [this.inputKey];
}
get outputKeys() {
return [this.outputKey];
}
constructor(fields) {
super(fields);
Object.defineProperty(this, "chains", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "inputKey", {
enumerable: true,
configurable: true,
writable: true,
value: "input"
});
Object.defineProperty(this, "outputKey", {
enumerable: true,
configurable: true,
writable: true,
value: "output"
});
Object.defineProperty(this, "trimOutputs", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
this.chains = fields.chains;
this.trimOutputs = fields.trimOutputs ?? false;
this._validateChains();
}
/** @ignore */
_validateChains() {
for (const chain of this.chains) {
if (chain.inputKeys.filter((k) => !chain.memory?.memoryKeys.includes(k) ?? true).length !== 1) {
throw new Error(`Chains used in SimpleSequentialChain should all have one input, got ${chain.inputKeys.length} for ${chain._chainType()}.`);
}
if (chain.outputKeys.length !== 1) {
throw new Error(`Chains used in SimpleSequentialChain should all have one output, got ${chain.outputKeys.length} for ${chain._chainType()}.`);
}
}
}
/** @ignore */
async _call(values, runManager) {
let input = values[this.inputKey];
let i = 0;
for (const chain of this.chains) {
i += 1;
input = (await chain.call({ [chain.inputKeys[0]]: input, signal: values.signal }, runManager?.getChild(`step_${i}`)))[chain.outputKeys[0]];
if (this.trimOutputs) {
input = input.trim();
}
await runManager?.handleText(input);
}
return { [this.outputKey]: input };
}
_chainType() {
return "simple_sequential_chain";
}
static async deserialize(data) {
const chains = [];
const serializedChains = data.chains;
for (const serializedChain of serializedChains) {
const deserializedChain = await base_js_1.BaseChain.deserialize(serializedChain);
chains.push(deserializedChain);
}
return new SimpleSequentialChain({ chains });
}
serialize() {
const chains = [];
for (const chain of this.chains) {
chains.push(chain.serialize());
}
return {
_type: this._chainType(),
chains,
};
}
}
exports.SimpleSequentialChain = SimpleSequentialChain;