John Paul Ada johnpaulada

I've been working with Apache Kafka for over 7 years. I inevitably find myself doing the same set of activities while I'm developing or working with someone else's system. Here's a set of Kafka productivity hacks for doing a few things way faster than you're probably doing them now. 🔥

Show me all my Kafka topics and their partitions, replicas, and consumers
Show me the contents of a topic
Create a Kafka topic
Produce messages to a Kafka topic
Validate the schema of messages before producing to a topic
Do all of this at a distance

Get the tools

Moved to Shopify/graphql-design-tutorial

Note:

When this guide is more complete, the plan is to move it into Prepack documentation.
For now I put it out as a gist to gather initial feedback.

A Gentle Introduction to Prepack (Part 1)

If you're building JavaScript apps, you might already be familiar with some tools that compile JavaScript code to equivalent JavaScript code:

Babel lets you use newer JavaScript language features, and outputs equivalent code that targets older JavaScript engines.

Phantom types in ReasonML

Introduction

"A phantom type is a parametrised type whose parameters do not all appear on the right-hand side of its definition..." Haskell Wiki, PhantomType

The following write-up is intended as an introduction into using phantom types in ReasonML.

Taking a look at the above definition from the Haskell wiki, it states that phantom types are parametrised types where not all parameters appear on the right-hand side. Let's try to see if we can implement a similar example as in said wiki.

From time to time, Musk will send out an e-mail to the entire company to enforce a new policy or let them know about something that's bothering him. One of the more famous e-mails arrived in May 2010 with the subject line: Acronyms Seriously Suck:

There is a creeping tendency to use made up acronyms at SpaceX. Excessive use of made up acronyms is a significant impediment to communication and keeping communication good as we grow is incredibly important. Individually, a few acronyms here and there may not seem so bad, but if a thousand people are making these up, over time the result will be a huge glossary that we have to issue to new employees. No one can actually remember all these acronyms and people don't want to seem dumb in a meeting, so they just sit there in ignorance. This is particularly tough on new employees.

That needs to stop immediately or I will take drastic action - I have given enough warning over the years. Unless an acronym is approved by me, it should not enter the SpaceX glossary.

Note: I'm not involved in Prepack in any way — please correct me if I say anything incorrect below!

A few people have asked me if Prepack and Svelte are similar projects with similar goals. The answer is 'no, they're not', but let's take a moment to explore why.

What is Prepack?

Prepack describes itself as a 'partial evaluator for JavaScript'. What that means is that it will run your code in a specialised interpreter that, rather than having some effect on the world (like printing a message to the console), will track the effects that would have happened and express them more directly.

So for example if you give it this code...

	section ‹A Simple Graph Problem›

	text ‹
	We shall prove the following: "In a finite group of people, some of whom are friends with some
	of the others there must be at least two people who have the same number of friends."
	›

	theory Friends
	imports Main
	Finite_Set

	let str = ReasonReact.string;

	let el = ReasonReact.element;

	let arr = ReasonReact.array;

	module Dashboard = {
	let component = ReasonReact.statelessComponent("Dashboard");
	let make = _children => {
	...component,

	{
	"emojis": [
	{"emoji": "👩‍👩‍👧‍👧", "name": "family: woman, woman, girl, girl", "shortname": ":woman_woman_girl_girl:", "unicode": "1F469 200D 1F469 200D 1F467 200D 1F467", "html": "👩&zwj;👩&zwj;👧&zwj;👧", "category": "People & Body (family)", "order": ""},
	{"emoji": "👩‍👩‍👧‍👦", "name": "family: woman, woman, girl, boy", "shortname": ":woman_woman_girl_boy:", "unicode": "1F469 200D 1F469 200D 1F467 200D 1F466", "html": "👩&zwj;👩&zwj;👧&zwj;👦", "category": "People & Body (family)", "order": ""},
	{"emoji": "👩‍👩‍👦‍👦", "name": "family: woman, woman, boy, boy", "shortname": ":woman_woman_boy_boy:", "unicode": "1F469 200D 1F469 200D 1F466 200D 1F466", "html": "👩&zwj;👩&zwj;👦&zwj;👦", "category": "People & Body (family)", "order": ""},
	{"emoji": "👨‍👩‍👧‍👧", "name": "family: man, woman, girl, girl", "shortname": ":man_woman_girl_girl:", "unicode": "1F468 200D 1F469 200D 1F467 200D 1F467", "html": "👨&zwj;👩&z