How to model your entities - 11

Message.ts

import { createFold } from ‘@iadvize-oss/foldable-helpers’;

// fold :: (TextMessage -> R) -> (ImageMessage -> R) -> (AudioMessage -> R) -> Message -> R
// “feeding” the fold-creator with our previously created type guards
const fold = createFold(isText, isImage, isAudio);

// or, passing function with an object to give them names

import { createFoldObject } from ‘@iadvize-oss/foldable-helpers’;

// fold :: ({
//  isText: TextMessage -> R,
//  isImage: ImageMessage -> R,
//  isAudio: AudioMessage -> R
// }) -> Message -> R
const fold = createFoldObject({ isText, isImage, isAudio });