44 lines
1.7 KiB
JavaScript
44 lines
1.7 KiB
JavaScript
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import { OutputParserException } from "@langchain/core/output_parsers";
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import { JsonMarkdownStructuredOutputParser } from "./structured.js";
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/**
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* A type of output parser that extends the
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* JsonMarkdownStructuredOutputParser. It is used to parse the output of a
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* router in LangChain. The class takes a schema and an optional
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* RouterOutputParserInput object as parameters.
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*/
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export class RouterOutputParser extends JsonMarkdownStructuredOutputParser {
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constructor(schema, options) {
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super(schema);
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Object.defineProperty(this, "defaultDestination", {
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enumerable: true,
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configurable: true,
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writable: true,
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value: "DEFAULT"
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});
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this.defaultDestination =
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options?.defaultDestination ?? this.defaultDestination;
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}
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/**
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* Overrides the parse method from JsonMarkdownStructuredOutputParser.
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* This method takes a string as input, attempts to parse it, and returns
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* the parsed text. If the destination of the parsed text matches the
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* defaultDestination, the destination is set to null. If the parsing
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* fails, an OutputParserException is thrown.
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* @param text The text to be parsed.
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* @returns The parsed text as a Promise.
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*/
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async parse(text) {
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try {
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const parsedText = await super.parse(text);
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if (parsedText.destination?.toLowerCase() ===
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this.defaultDestination.toLowerCase()) {
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parsedText.destination = null;
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}
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return parsedText;
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}
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catch (e) {
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throw new OutputParserException(`Failed to parse. Text: "${text}". Error: ${e}`, text);
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}
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}
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}
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