62 lines
2.2 KiB
JavaScript
62 lines
2.2 KiB
JavaScript
|
import { OutputParserException } from "@langchain/core/output_parsers";
|
||
|
|
import { AgentActionOutputParser } from "../types.js";
|
||
|
|
import { FORMAT_INSTRUCTIONS } from "./prompt.js";
|
||
|
|
export const FINAL_ANSWER_ACTION = "Final Answer:";
|
||
|
|
/**
|
||
|
|
* A class that extends `AgentActionOutputParser` to provide a custom
|
||
|
|
* implementation for parsing the output of a ZeroShotAgent action.
|
||
|
|
*/
|
||
|
|
export class ZeroShotAgentOutputParser extends AgentActionOutputParser {
|
||
|
|
constructor(fields) {
|
||
|
|
super(fields);
|
||
|
|
Object.defineProperty(this, "lc_namespace", {
|
||
|
|
enumerable: true,
|
||
|
|
configurable: true,
|
||
|
|
writable: true,
|
||
|
|
value: ["langchain", "agents", "mrkl"]
|
||
|
|
});
|
||
|
|
Object.defineProperty(this, "finishToolName", {
|
||
|
|
enumerable: true,
|
||
|
|
configurable: true,
|
||
|
|
writable: true,
|
||
|
|
value: void 0
|
||
|
|
});
|
||
|
|
this.finishToolName = fields?.finishToolName || FINAL_ANSWER_ACTION;
|
||
|
|
}
|
||
|
|
/**
|
||
|
|
* Parses the text output of an agent action, extracting the tool, tool
|
||
|
|
* input, and output.
|
||
|
|
* @param text The text output of an agent action.
|
||
|
|
* @returns An object containing the tool, tool input, and output extracted from the text, along with the original text as a log.
|
||
|
|
*/
|
||
|
|
async parse(text) {
|
||
|
|
if (text.includes(this.finishToolName)) {
|
||
|
|
const parts = text.split(this.finishToolName);
|
||
|
|
const output = parts[parts.length - 1].trim();
|
||
|
|
return {
|
||
|
|
returnValues: { output },
|
||
|
|
log: text,
|
||
|
|
};
|
||
|
|
}
|
||
|
|
const match = /Action:([\s\S]*?)(?:\nAction Input:([\s\S]*?))?$/.exec(text);
|
||
|
|
if (!match) {
|
||
|
|
throw new OutputParserException(`Could not parse LLM output: ${text}`);
|
||
|
|
}
|
||
|
|
return {
|
||
|
|
tool: match[1].trim(),
|
||
|
|
toolInput: match[2]
|
||
|
|
? match[2].trim().replace(/^("+)(.*?)(\1)$/, "$2")
|
||
|
|
: "",
|
||
|
|
log: text,
|
||
|
|
};
|
||
|
|
}
|
||
|
|
/**
|
||
|
|
* Returns the format instructions for parsing the output of an agent
|
||
|
|
* action in the style of the ZeroShotAgent.
|
||
|
|
* @returns The format instructions for parsing the output.
|
||
|
|
*/
|
||
|
|
getFormatInstructions() {
|
||
|
|
return FORMAT_INSTRUCTIONS;
|
||
|
|
}
|
||
|
|
}
|