fast-topics/dist/topics.js

Unsupervised topic extraction from text using Latent Dirichlet Allocation in WebAssembly

import { setupEnvironment } from './wasm_exec.js';
setupEnvironment(); //  needs to set up before anything else will work
/**
 * set WASM initialisation function to fetching a URL of the .wasm file
 */
export const initWithFetch = (url = "node_modules/fast-topics/dist/topics.wasm") => async () => {
    const go = new Go();
    await WebAssembly.instantiateStreaming(fetch(url), go.importObject)
        .then((result) => {
        go.run(result.instance).then(() => console.log('WASM functions no longer available'));
    });
    console.log('Init WASM using fetch');
};
/**
 * set WASM initialisation function to ArrayBuffer binary (slower than fetching URL)
 */
export const initWithBinary = (binary) => async () => {
    const go = new Go();
    await WebAssembly.instantiate(binary, go.importObject)
        .then((result) => {
        go.run(result.instance).then(() => console.log('WASM functions no longer available'));
    });
    console.log('Init WASM using binary ArrayBuffer');
};
let initWasm = initWithFetch();
/**
 * set the initialisation function. Defaults to fetch URL.
 */
export const setInitFunction = (initFunc) => {
    initWasm = initFunc;
};
/**
 * call this before calling the getTopics function
 */
export async function initialiseWasm(input) {
    if (isGetTopicsReady())
        console.warn('WASM has already been initialised');
    if (typeof input === 'string')
        setInitFunction(initWithFetch(input));
    else if (input instanceof ArrayBuffer)
        setInitFunction(initWithBinary(input));
    else if (input)
        console.warn("Invalid input to 'initialiseWasm'. Must be either URL: string, or binary: ArrayBuffer");
    await initWasm();
    console.assert(isGetTopicsReady(), 'fast-topics WebAssembly module failed to instantiate');
}
const defaultGetTopicsOptions = {
    numberOfTopics: 5, topicsMinWordRank: 0, docsMinTopicRank: 0
};
/**
 * Get the topics in a set of documents (strings).
 * @param docs - an array of strings, where each string is a "document".
 * @param opts - options for the topic extraction
 */
export const getTopics = (docs, opts) => {
    if (!isGetTopicsReady()) {
        throw new Error("WASM has not been initialised. Call `await intialiseWasm()`");
    }
    try {
        const options = { ...defaultGetTopicsOptions, ...opts };
        const result = getTopicsString(docs, options);
        if (typeof result === "string")
            return JSON.parse(result);
        else if (result instanceof Error)
            throw result;
        else
            throw new Error("Unrecognised value returned: " + typeof result + '. Value=' + String(result));
    }
    catch (e) {
        console.error('Error occurred while calling WASM function "getTopicsString":', e.message);
    }
};
/**
 * Returns true if getTopics() is ready to be called. This depends on the WebAssembly module being instantiated first.
 */
export const isGetTopicsReady = () => typeof getTopicsString !== 'undefined';
//# sourceMappingURL=topics.js.map