OutputParser that parses LLMResult into the top likely string.

Example

const promptTemplate = PromptTemplate.fromTemplate(
"Tell me a joke about {topic}",
);

const chain = RunnableSequence.from([
promptTemplate,
new ChatOpenAI({}),
new StringOutputParser(),
]);

const result = await chain.invoke({ topic: "bears" });
console.log("What do you call a bear with no teeth? A gummy bear!");

Hierarchy

Constructors

Properties

name?: string

Methods

  • Calls the parser with a given input and optional configuration options. If the input is a string, it creates a generation with the input as text and calls parseResult. If the input is a BaseMessage, it creates a generation with the input as a message and the content of the input as text, and then calls parseResult.

    Parameters

    • input: string | BaseMessage

      The input to the parser, which can be a string or a BaseMessage.

    • Optional options: RunnableConfig

      Optional configuration options.

    Returns Promise<string>

    A promise of the parsed output.

  • Parses a string output from an LLM call. This method is meant to be implemented by subclasses to define how a string output from an LLM should be parsed.

    Parameters

    • text: string

      The string output from an LLM call.

    Returns Promise<string>

    A promise of the parsed output.

  • Stream all output from a runnable, as reported to the callback system. This includes all inner runs of LLMs, Retrievers, Tools, etc. Output is streamed as Log objects, which include a list of jsonpatch ops that describe how the state of the run has changed in each step, and the final state of the run. The jsonpatch ops can be applied in order to construct state.

    Parameters

    Returns AsyncGenerator<RunLogPatch, any, unknown>

  • Bind lifecycle listeners to a Runnable, returning a new Runnable. The Run object contains information about the run, including its id, type, input, output, error, startTime, endTime, and any tags or metadata added to the run.

    Parameters

    • params: {
          onEnd?: ((run, config?) => void | Promise<void>);
          onError?: ((run, config?) => void | Promise<void>);
          onStart?: ((run, config?) => void | Promise<void>);
      }

      The object containing the callback functions.

      • Optional onEnd?: ((run, config?) => void | Promise<void>)
          • (run, config?): void | Promise<void>
          • Called after the runnable finishes running, with the Run object.

            Parameters

            Returns void | Promise<void>

      • Optional onError?: ((run, config?) => void | Promise<void>)
          • (run, config?): void | Promise<void>
          • Called if the runnable throws an error, with the Run object.

            Parameters

            Returns void | Promise<void>

      • Optional onStart?: ((run, config?) => void | Promise<void>)
          • (run, config?): void | Promise<void>
          • Called before the runnable starts running, with the Run object.

            Parameters

            Returns void | Promise<void>

    Returns Runnable<string | BaseMessage, string, RunnableConfig>

Generated using TypeDoc