Mario KB coleea

Technical overview

A basic `Option` type

// Option.ts

// definition
export class None {
  readonly tag: 'None' = 'None'

This tutorial explains how Unison handles 'effectful' computations, like storing state or performing I/O, using abilities. It assumes you haven't come across abilities before, and covers everything from the ground up.

This is an unofficial tutorial, written before the one on unisonweb.org/docs. The approach taken here is slow and methodical. Your first stop should be the official tutorial, if you haven't seen it already.

This doc is a Unison transcript - the source is here.

Terminology note: other languages with ability systems typically call them 'effect handlers' or 'algebraic effects', but many of the ideas are the same.

Introducing abilities

How to setup next.js app on nginx with letsencrypt

next.js, nginx, reverse-proxy, ssl

1. Install nginx and letsencrypt

$ sudo apt-get update
$ sudo apt-get install nginx letsencrypt

	import React from 'react';
	import _ from 'lodash';
	import Rx from 'rx';
	import superagent from 'superagent';

	let api = {
	host: 'http//localhost:3001',

	getData(query, cb) {
	superagent

	# Detect architecture

	if (CMAKE_SIZEOF_VOID_P MATCHES 8)
	set( PROJECT_ARCH "x86_64" )
	else(CMAKE_SIZEOF_VOID_P MATCHES 8)
	set( PROJECT_ARCH "x86" )
	endif(CMAKE_SIZEOF_VOID_P MATCHES 8)

	# FFmpeg

	const daggy = require('daggy')

	const compose = (f, g) => x => f(g(x))
	const id = x => x
	const kleisli_comp = (f, g) => x => f(x).chain(g)

	//=============FREE=============
	const Free = daggy.taggedSum({Impure: ['x', 'f'], Pure: ['x']})
	const {Impure, Pure} = Free

	/* Cheerio-powered parser for the DJ DATA score page on the beatmania IIDX website.
	Requires 'cheerio', 'request', and 'iconv' packages.

	Needs 'Cookie' header from manual login for authentication.

	Results in an array of JSON-formatted scores, which looks like this:
	{
	"songs": [{
	"song": {
	"name": "SONG NAME",

	import { OutputOf, string, type, Type, TypeOf, Validation } from 'io-ts';
	import React, { FC, useState } from 'react';
	import { either, left, map, right } from 'fp-ts/lib/Either';
	import { sequenceS } from 'fp-ts/lib/Apply';
	import { NumberFromString } from 'io-ts-types/lib/NumberFromString';
	import { pipe } from 'fp-ts/lib/pipeable';

	const formDataCodec = type({
	age: NumberFromString,
	password: string,

	/*
	Generate io-ts codecs and types for JSON data from a set of samples using jq, quicktype and io-ts-codegen

	Usage:

	# collect samples
	for i in $(seq 1 10); do
	wget -P samples/ https://api.github.com/events && sleep 2
	done

	import React, { useState, useEffect, useCallback } from 'react';

	// Usage
	function App() {
	const { execute, status, value, error } = useAsync(myFunction, false);

	return (
	<div>
	{status === 'idle' && <div>Start your journey by clicking a button</div>}
	{status === 'success' && <div>{value}</div>}