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Sebastiaan Andeweg
Seblog.nl

Seblog.nl

So many times I see developers using the word 'physical' when they are still referring to some virtual thing, just one layer less abstract.

Some other weird things about falsy Javascript:

false == false
0 == false
[] == false
"" == false
"0" == false
"\t" == false
[] == false
["0"] == false
[[["0"]]] == false
[[[1 - 1]]] == false
[[[{}.foobar]]] == false
[[[`\t ${[].length} \t`]]] == false

// BUT

[false] != false

So, yesterday I learned that [] == [] is false in Javascript. Today my adventures with arrays lead me to this:

const coffees = ['espresso', 'latte', 'filter']
console.log(
  'filter' in coffees,
  'cappuchino' in coffees,
  'espresso' in coffees
)

// => true, false, false

I don't understand why people prefer arrow-functions in Javascript in the following context:

const name = () => stuff();

vs

function name() {
  stuff();
}

... they are ideal for callbacks and map-operations, but when I want to declare a function, I want to see that keyword.

Dus, je lichaam is opgebouwd uit cellen, en de langst-levende cel leeft zeven jaar. Eigenlijk zijn alle cellen in je lichaam dus gemaakt van iets dat je de afgelopen zeven jaar hebt gegeten. Tenzij je jonger dan zeven bent, dan heeft je moeder meegegeten.

So, I've been addicted to Tetris for the last week or so. Last night I decided to do something else, and when I came across the Phoenix LiveView contest, I thought: why not try and make Tetris? #myelixirstatus

I was surprised by how far I got. I have watched videos of people coding games before, have been coding myself for years and years, but somehow games felt out of my league. But here, after a (long) evening, I got a game! I should've streamed it myself.

I mean I'm standing of shoulders of giants. I got so much for free from Erlang/Elixir, LiveView to hook it up, @chris_mccord's Snake example gave me the basic idea of using just <div>'s for blocks, the browser is doing the drawing and key-repeats for me.

But it felt magical, once the game got playable. I was hooked again to my own creation. And so many "features" from NES Tetris like sliding, tucking and spinning "just worked" in my first implementation (probably because I was close to their implementation).

It all started with this HTML based board, using flexbox to to the hard works of blocks for me. I later wrapped the board in a Game-struct, and added bindings for the scores.

How to get a game loop in Elixir? Just send yourself a message after, say, 500ms. The LiveView component has a handle_info/2, which queues the next tick and moves the current Tetromino down.

Thanks to the phx-keydown="keydown" in the template, we get messages in handle_event/3 for each key. Just delegating to my Game module. And yes, I use Vim, so I need those H, J and L. (Dropping with K is not implemented.)

My Game.move/2 got a bit complicated, some refactoring is in place. But I started with a Tetromino struct, with :x and :y keys and a :color. To move it down, you paint the current :x and :y :white, and then paint :y + 1 to the :color. Code below reduces for all four points:

To obtain all the points I got this wonderful Tetromino.points/1 function. It's ugly and was a pain to write out and get right, but it works like a charm.

Colors and rotations work similar, with Tetromino.rotate/1. (color_for_type/1 gets called in new/1, and it never changes once it is created.)

Then the messy Game.move/1: can you move down? Move down. Otherwise, call Board.clear_lines/1 to remove full lines and obtain the score, get a new random Tetromino and put it on the board. The game-over handling is a bit buggy still, I had only one evening.

Clearing the board is simple: reject rows of which all cells are not empty and use counts to add new rows to the top. The Board.color_at/2 gives the color for that particular cell. The guards against negative numbers prevent List.pop_at/2 to get items from the back of the list :)

I think that's mostly it! Again, I wish I had streamed it, it was very weird watching myself doing it, but also very rewarding. Keep coding, people, you can do this too!

Ok, ik heb dus net een soort zijbalk gemaakt die bovenaan de pagina blijft staan als je scrollt en ik ben daar onevenredig blij mee. Er is eigenlijk niets leuker dan een beetje CSS uitproberen op je eigen site.

Surf the web at lightning speed

I am at an airport, and I just saw a booth where I could access the web for free if I had the right card, or for a certain amount of euros per time unit. I saw the Microsoft Internet Explorer logo. All the computers where available, except for one. I assumed the girl that was using it worked there. Why else would you use a place like that?

It made me realise how much the web has changed. In another era, there were publishers, who put information on paper. These papers could then be brought by those who were interested in the information. It was a publishers world. The story has been told many times: the internet changed that, information became free, anyone could publish. But the web has evolved once more.

Why would I not want to use a computer in that booth even if it were free? Because I have no idea what to do on the web. Do I go to some news sites? Do I look up the time of my flight again? It would only be to kill time. Most of the public information is boring, the real fun is on Twitter, Facebook or maybe even my e-mail, where the information is tailored to my tastes. And no, I would not feel okay with entering my password into one of those things.

I should probably not call the social media part of the internet ‘the web’. It is partly not accessable without logging in, not all parts have clear URLs, it depends on a few giant websites. But there’s more fun on those silo’s, or at least: there is more of that promised content, published by anyone, everyone, especially your friends. And the best way of viewing it, is by authenticating myself as me. Luckily this is not a problem: I have a device in my pocket that is connected and authenticated 24/7. Compared to that, the web is a dull place, with unpersonal information.

Will the web make place for these giant silo’s? Is the time of publishing on your own site over? I hope not. I’m experimenting with this on this website, which is my personal website. There is a link in the upper-right corner which says ‘log in’. That is not a link for me, that is a link for you. You can log in using various methods (ok, only IndieAuth and Twitter are supported at the time of writing). After you are logged in you will see more posts, like my checkin into the airport. If I know you and shared a post especially with you, you will see those as well.

We still need some work on staying authenticated, preferably to one app that collects private posts for you, as you. But there is more web in this approach than we have in social media. And that is nice. I like more web. The web is exciting. Let’s not let it stay boring with only public, general information. Let’s share the personal here too. And let’s create a way to do that in a more private way, where you control who sees your posts. See you on the IndieWeb!

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