@langchain/core/dist/example_selectors/length_based.d.ts

Core LangChain.js abstractions and schemas

import { Example } from "../prompts/base.js";
import { BaseExampleSelector } from "./base.js";
import { PromptTemplate } from "../prompts/prompt.js";
/**
 * Interface for the input parameters of the LengthBasedExampleSelector
 * class.
 */
export interface LengthBasedExampleSelectorInput {
    examplePrompt: PromptTemplate;
    maxLength?: number;
    getTextLength?: (text: string) => number;
}
/**
 * A specialized example selector that selects examples based on their
 * length, ensuring that the total length of the selected examples does
 * not exceed a specified maximum length.
 * @example
 * ```typescript
 * const exampleSelector = new LengthBasedExampleSelector(
 *   [
 *     { input: "happy", output: "sad" },
 *     { input: "tall", output: "short" },
 *     { input: "energetic", output: "lethargic" },
 *     { input: "sunny", output: "gloomy" },
 *     { input: "windy", output: "calm" },
 *   ],
 *   {
 *     examplePrompt: new PromptTemplate({
 *       inputVariables: ["input", "output"],
 *       template: "Input: {input}\nOutput: {output}",
 *     }),
 *     maxLength: 25,
 *   },
 * );
 * const dynamicPrompt = new FewShotPromptTemplate({
 *   exampleSelector,
 *   examplePrompt: new PromptTemplate({
 *     inputVariables: ["input", "output"],
 *     template: "Input: {input}\nOutput: {output}",
 *   }),
 *   prefix: "Give the antonym of every input",
 *   suffix: "Input: {adjective}\nOutput:",
 *   inputVariables: ["adjective"],
 * });
 * console.log(dynamicPrompt.format({ adjective: "big" }));
 * console.log(
 *   dynamicPrompt.format({
 *     adjective:
 *       "big and huge and massive and large and gigantic and tall and much much much much much bigger than everything else",
 *   }),
 * );
 * ```
 */
export declare class LengthBasedExampleSelector extends BaseExampleSelector {
    protected examples: Example[];
    examplePrompt: PromptTemplate;
    getTextLength: (text: string) => number;
    maxLength: number;
    exampleTextLengths: number[];
    constructor(data: LengthBasedExampleSelectorInput);
    /**
     * Adds an example to the list of examples and calculates its length.
     * @param example The example to be added.
     * @returns Promise that resolves when the example has been added and its length calculated.
     */
    addExample(example: Example): Promise<void>;
    /**
     * Calculates the lengths of the examples.
     * @param v Array of lengths of the examples.
     * @param values Instance of LengthBasedExampleSelector.
     * @returns Promise that resolves with an array of lengths of the examples.
     */
    calculateExampleTextLengths(v: number[], values: LengthBasedExampleSelector): Promise<number[]>;
    /**
     * Selects examples until the total length of the selected examples
     * reaches the maxLength.
     * @param inputVariables The input variables for the examples.
     * @returns Promise that resolves with an array of selected examples.
     */
    selectExamples(inputVariables: Example): Promise<Example[]>;
    /**
     * Creates a new instance of LengthBasedExampleSelector and adds a list of
     * examples to it.
     * @param examples Array of examples to be added.
     * @param args Input parameters for the LengthBasedExampleSelector.
     * @returns Promise that resolves with a new instance of LengthBasedExampleSelector with the examples added.
     */
    static fromExamples(examples: Example[], args: LengthBasedExampleSelectorInput): Promise<LengthBasedExampleSelector>;
}