dypsilon’s gists

dypsilon / .eslintrc.json

Created May 30, 2023 21:29

TypeScript ESLint Prettier Setup

	{
	"parser": "@typescript-eslint/parser",
	"plugins": [
	"@typescript-eslint",
	"prettier"
	],
	"extends": [
	"eslint:recommended",
	"plugin:@typescript-eslint/eslint-recommended",
	"plugin:@typescript-eslint/recommended",

dypsilon / blog-async-await-waterfall.js

Created March 24, 2017 19:15

	async function addComment(comment) {
	const post = await fetchPostBySlug(comment.postSlug);

	if (!post.isCommentingEnabled) {
	throw new Error('Commenting is disabled.');
	}

	const isAllowed = await isUserAllowedToComment(post, comment.user);

	if (!isAllowed) {

dypsilon / blog-async-await-chained-promises.js

Created March 24, 2017 19:11

	function addComment(comment) {
	return fetchPostBySlug(comment.postSlug)
	.then((post) => {
	if (!post.isCommentingEnabled) {
	return Promise.reject(new Error('Commenting is disabled.'));
	}

	return isUserAllowedToComment(post, comment.user)
	.then((isAllowed) => ({ isAllowed, post }));
	}).then((input) => {

dypsilon / blog-async-await-nested-promises.js

Created March 24, 2017 19:04

	function addComment(comment) {
	return fetchPostBySlug(comment.postSlug).then((post) => {
	if (!post.isCommentingEnabled) {
	return Promise.reject(new Error('Commenting is disabled.'));
	}

	return isUserAllowedToComment(post, comment.user).then((isAllowed) => {
	if (!isAllowed) {
	return Promise.reject(
	new Error('The user is not allowed to comment on this post.')

dypsilon / blog-async-await-callbacks.js

Created March 24, 2017 18:58

	function addComment(comment, done) {
	fetchPostBySlug(comment.postSlug, (err, post) => {
	if (err) return done(err);

	if (!post.isCommentingEnabled) {
	return done(new Error('Commenting is disabled.'));
	}

	isUserAllowedToComment(post, comment.user, (err, isAllowed) => {
	if (err) return done(err);

dypsilon / async-await-1.json

Created March 21, 2017 21:44

	{
	"user": "58bb380d222c2239a2b16ae9",
	"postSlug": "is-learning-dangerous",
	"comment": "A little learning is a dangerous thing."
	}

dypsilon / reader-t.js

Last active December 27, 2017 03:53

In this example, the save method produces an error and we use mapLower to call a special Future function "mapRej", which transforms all incoming errors.

	const {tagged} = require('daggy');

	// const
	const K = (a) => (b) => a;

	// Reader Transformer
	module.exports = (M) => {
	const ReaderT = tagged('run');

	ReaderT.lift = ReaderT.prototype.lift = (m) => ReaderT(K(m));

dypsilon / reader-t.js

Last active October 28, 2020 22:25

A simple example of using Reader transformer to combine reader and future.

	const {tagged} = require('daggy');

	// const
	const K = (a) => (b) => a;

	// Reader Transformer
	module.exports = (M) => {
	const ReaderT = tagged('run');

	ReaderT.lift = (m) => ReaderT(K(m));

dypsilon / reader_future.js

Created August 9, 2016 19:21

Reader + Future Monads Usage

	/**
	* This short program will encrypt the user password
	* and insert a new record into a mock database.
	*/
	const Reader = require('fantasy-readers');
	const Future = require('fluture');
	const R = require('ramda');
	const crypto = require('crypto');

	// our mock database

dypsilon / reader.js

Last active April 28, 2024 08:50

Example usage of the reader monad.

	/**
	* This short program will encrypt the user password
	* and insert a new record into a mock database.
	*/
	const Reader = require('fantasy-readers');
	const R = require('ramda');
	const crypto = require('crypto');

	// our mock database
	const database = [

Tim Navrotskyy dypsilon