langchain/src/output_parsers/noop.ts

import { BaseOutputParser } from "@langchain/core/output_parsers";

/**
 * The NoOpOutputParser class is a type of output parser that does not
 * perform any operations on the output. It extends the BaseOutputParser
 * class and is part of the LangChain's output parsers module. This class
 * is useful in scenarios where the raw output of the Large Language
 * Models (LLMs) is required.
 */
export class NoOpOutputParser extends BaseOutputParser<string> {
  static lc_name() {
    return "NoOpOutputParser";
  }

  lc_namespace = ["langchain", "output_parsers", "default"];

  lc_serializable = true;

  /**
   * This method takes a string as input and returns the same string as
   * output. It does not perform any operations on the input string.
   * @param text The input string to be parsed.
   * @returns The same input string without any operations performed on it.
   */
  parse(text: string): Promise<string> {
    return Promise.resolve(text);
  }

  /**
   * This method returns an empty string. It does not provide any formatting
   * instructions.
   * @returns An empty string, indicating no formatting instructions.
   */
  getFormatInstructions(): string {
    return "";
  }
}