Rust Programming Language RustFest Barcelona 2019, 27 Nov 2019

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From YouTube: RustFest Barcelona - Claudia Saxer: 66 hours of Rust

Description

Is it possible to learn Rust from Zero in just 66 hours? In this experience report I will tell you about the good, the bad and the ugly that I experienced on my journey through the universe of Rust from the perspective of a C# and TypeScript developer.

https://barcelona.rustfest.eu/sessions/66-hours-of-rust

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Claudia: so hi, everyone., I'm thrilled to be here and a bit nervous as well.

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So can you please switch the slide?.

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Awesome., so I am going to talk about the good,, the bad and the ugly of rust I experienced in.

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The last months learning rust. does anyone actually know the movie?.

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Hands: up. oh, awesome. nice, a lot of people.

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So, who am I?? My name is claudia,. I'm a software engineer working with c# in switzerland in a big engineering.

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Company,, so why did I learn rust?.

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How come I learned rust at all?.

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It's kind of a funny story., a friend of mine, asked me to write a proposal for the rustfest and I don't know any rust.

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At all. never actually,, I heard about rust just doing my studying, like five years ago, hearing.

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About the memory safety of rust, but nothing more and not really looking into it.

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Also in the c# world, you actually hear about rust with webassembly.

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C# and webassembly are getting a thing and a lot of examples actually with rust.

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So I thought to myself:: it would be fun to talk at the rustfest and writing a proposal.

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Not a lot of pressure at all,, but I mean they are not going to take me anyway,. So, let's.

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So I felt like this guy, angel eyes from the movie.

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You know, the pity is, when I'm paid,. I always follow my job through.

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So that was a month ago and I started to learn rust.

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So I'm going to talk about my journey,, the good,, the bad and the ugly.

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Here you can see some kind of motivational chart.

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In the beginning, it's awesome, like I can learn a new language.

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I can learn rust., so it's a really great time.. Then you can see the first bump.

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That was an experience with tooling.. I am going to tell you about it.

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The second bump here is webassembly, and the last one where I hit rock bottom, was javascript.

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So that's how it started,, like clint, eastwood said:. The way back to town is only 70 miles.

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So if you save your breath, I think a man like you can manage it.

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so clint eastwood,, the handsome guy here,, is the good guy in the movie, and that was.

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Like rust, for me as well., I started learning rust with the rust link page and some youtube tutorials just to get.

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To know the types and the differences with c# as well.

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Some parts that I really enjoyed,, I found it really easy to read rust, itself.

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If you know some programming languages,, you can look at it and you can somehow read it.

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I haven't looked at all the macros yet so I heard some rumours there.

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Traits and structs is something I really enjoyed because I come from the object, oriented world,.

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So I could use a lot of the same series. There.

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Also, the syntax,, you know the dot dot you can use,. I really enjoy that syntax.

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C#, I think brought that at the last update with the array index and I was happy to see.

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I think my favourite part of the language was the loop statement.

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So this is the first language ever that I saw you actually have a statement for loop.

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And you don't have to write "while true" and it just saved some time and that anyone thought.

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About it and did it,, I think that's really awesome.

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So stuff that I found a bit weird was the snake_case.

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I am used to camel case and pascal case..

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I will get used to it.

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And then the return statement,, but at the first examples I just thought it was like.

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Any other language,, and then I saw you can actually just write one and it does the same.

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It returns one, so I was asking myself:: why does rust have that?.

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Why does it do it? and I was confused at the start. now? I know actually that it just returns. The last statement, every time, and I like it.

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Then the ownership and the powering,, it's a new concept for me.

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So I somehow found it hard.

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It's a very steep learning curve, but it's, I think, one of the most important parts of.

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Rust because of the memory safety.

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But I still have a lot to learn: here.

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So the tooling.

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here you can see lee van cleef,, the bad guy,, but not everything is bad,, like with lee van.

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Cleef as well,, so I will start with the parts I enjoyed.

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For me, that tooling is like a friend.

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So I will sleep better.. My good friend is by my side to protect me.

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I used visual studio code.

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as you can see from the icon,. It's ide.

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Also something to mention,, I work with windows and not with linux,, so I think the visual.

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Studio code is one of the age preferred ides to use. If you work with rust, and I used cargo.

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As a package manager and also after some time, I realised:, how do I format my code?.

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I am going to have some possibility to format,, so I installed rustformat and I was confused.

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That it doesn't come with rls.

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So another part of the tooling are the error messages from the compiler,, so everyone I.

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Talked with about, the compiler messages from rust,, my expectations were up there about.

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Seeing the error messages, and then I happened to encounter this.

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So, as you can see, the message is not on the correct line.

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It's on the start of my implementation.

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and also the expected and found wasn't that much helping.

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That was a bit of a letdown,, maybe because my expectations were so high.

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But most of the time they were very helpful.

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So what was the bad part of my experience of the tooling?.

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You remember from my motivational chart, the first bump?.

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It was here. so, "god's, not on our side, because he hates idiots also", and the idiot was me.

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I don't know if you recognise the icon.

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It's visual studio., so I set out my tooling with visual studio code and it worked perfectly fine, and I was.

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Like:, why shouldn't it work with visual studio as well?.

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Let's try it., so some guy actually wrote an extension for visual studio to work across some years ago.

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For an old visual studio version,- and I tried it out.

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So I installed it and started visual studio and it didn't work.

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I googled and some guys found: hey,, let's deinstall the rls.

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If you start visual studio,, it will prompt you to install it.

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So that was like the low point and I said to myself: yes,: it won't work.

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I'm kind of an idiot trying it out with an earlier visual studio.

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So it was 2019 and I used '17, and I used 2019,. So then I got back to visual studio.

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Code and everything was working.

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I had to install rls and install it all again, but in the end it worked and I'm happy with.

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So then I began my journey.. I looked at the language,, the types, structs and traits and wanted to start a new project.

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With webassembly., so I saw this awesome github page for rust and webassembly with a tutorial called game.

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Of life,, which I followed like for the first quarter.

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I used wasm-pack to generate my webassembly package from rust,, which is really awesome.

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It reloads your web page if you change your code and run wasm-pack and it worked great,.

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And very fast, as well.

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Then the favourite part of my rust experience,, the console error, panic codes,, it's just two.

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Lines and it tests an error, panic hook, so it can see errors directly in the web page.

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Console so, if anything fails, you can actually see a message:. It failed on this line.

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A really good error, message.

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That was like the first time. I was really happy to see an error message.

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Also, I talked with some friends who used c# and webassembly and they don't have it.

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So if anything fails,, they just see nothing.

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The debugging with webassembly isn't that great yet.

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They are going to improve it,, but it's quite awful.

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So those things, a life saver.

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So the frontend.

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My two last hiccups are here.

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You can see here the ugly guy from the movie.

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For me, my experience like with webassembly was:, who the hell is that?.

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One bastard goes in and another one comes out.

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I started to use multi-threading with webassembly and rust.

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I tried it on a normal rust application to run in the console and it worked fine.

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It was fairly easy,, I would say,, and then I used it in my webassembly project and it.

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Said: awesome, we build it, smiley face.

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Everything is great., then I looked at my web. Page, refreshed it and there was this error. Message.

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It cannot actually find multi-threading because it's not actually packed to the webassembly.

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Package., it cannot find the module.

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So that didn't work., then I had to use for my little project like the system called time.

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I thought that has to work., so I called the time from rust, packed it.

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Everything was built perfectly with wasm-pack, and then it failed again.

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It also hasn't yet [inaudible].

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So these nice things with rust that I just can't use with webassembly one after another.

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So how can you still use the time that is obviously needed?.

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You can actually define it in javascript.

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You can see here on the bottom.

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Just have a function like get current time in milliseconds.

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Then, in the rust part you can say: hey, in that javascript file, this method, exists, and.

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Then just call it in rust, like any other function.

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Beside this call and the manipulation,, that's the only thing I had too it with javascript,.

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Which I really enjoyed. all the other functionality I could write in rust and then call it from javascript.

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So that's like the first draft of my application.

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It worked, but it wasn't pretty.

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I wanted to make it nice, as well.

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So I had at the moment one huge rust file, with all my functionality in it, and I wanted.

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To split it, up, like have a folder universe with my whole universe, from the application.

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And the library and structs and traits, so I had to use mod and use and crate to split.

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That was quite hard.. It was harder than I expected.

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Also, I looked on stack overflow to see some examples of how it could be done.

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It didn't work. later on. I heard that in 2018 it actually changed,. So there are still a lot of examples.

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That will not work,, so I used more hours than I wanted to say to make this happen.

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Then,, as I said, I used, structs and traits, which I really enjoyed to have the inheritance.

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That I'm used to. also,. I used a lot of generics, just to make it possible to have a functionality just written.

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Once., that was something I missed,, something like nested structs.

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I wanted to make inherent runs struct into another,, like you see in the example on the.

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Right., I hope to find something like that.

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But there's nothing possible to do it. This way.

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Maybe it has something to do with the ownership that rust isn't able to do. It.

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I don't know., so I did it as you can see on the left. Example.

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I just have a struct,. I call it here, part, that my other two structs use the fields from.

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Like count is used in apartments and roads.

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But I wanted to have it flat.

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But still in the end, I could accomplish what I wanted.

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So then, this happened.

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You remember my emotional chart?, the last point,, where I really hit rock bottom with the javascript?.

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That was this..

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I was like suddenly seeing a lot of red lines, like:, I'm your friend,, please don't die,! Please.

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Don't die. and it did.

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so what happened?

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it couldn't find. My webassembly module.

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It's like the one called city_inc_next and I tried to clean it, to do everything possible.

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That I knew about,, but I couldn't make it work again, so I used git through my little.

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Project and just thought:, let's just go back and see if it works there and what did I change.

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To break it, actually.

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Then I realised this one.

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when I started my webassembly project. I used this comment to have wasm-pack-template, which.

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Was pretty neat., it had a lot of things in it before, but what it actually does, it clones. This template.

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Into your www folder, so now you have a git repository in there, and if you do not delete.

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That .git folder, that git directory, and you just work on your route and naively just.

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Write git, add all,, git commit, and don't look at the files,. You will not really realised.

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That you haven't committed anything from your javascript part,, so I had no history at all.

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I didn't know what went wrong.

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So I had to start again.

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I created a new project and copied one file after another to see. Where did I fail, what.

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Did I do wrong, and I actually copied everything and it worked.

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So if anyone knows what could happen here and what went wrong, or anyone had the same.

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Problem,, please come afterwards to me and tell me what I did wrong.

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And delete the git directory.

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So that's almost to the end.

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What were my key takeaways?.

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I actually do recommend rust..

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I love to like, the whole language part of rust,, I really loved it, and I prefer it.

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To c++, like way a lot.

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I do want to learn: more, learn more about the whole memory, concept,, the ownership and.

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The borrowing, and I do think it's quite a steep learning, curve.

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A month, 66 hours,, I don't think it's enough.

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I can now write some code in rust,, but I wouldn't say I'm like a rust programmer.

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Yes. thank you..

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I think we have time for questions.

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I'm going myself through a learning process.

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Here. recently, I have hit some points where the documentation was either confusing or could.

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Have been better, and in some places I just got stuck because I couldn't go any further,.

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So what was in your case, one or two places where the documentation and maybe something.

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That could have been done better to get you over the hump of understanding some concept.

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Or issue,, maybe some error or something?.

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Claudia: hmm,, I think more examples,, just more coding, examples,, not just a hello world.

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Also in the stack overflow., maybe some people can write a version for us.

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Just as an addition,, you said you didn't look into macros.

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That was something that I hit recently, and just as a comment,. If somebody is going to.

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Do this, give an example of a macro which doesn't have a variable number of parameters.

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That would be very good., claudia: [laughing].

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Any other questions? not? okay, thanks, claudia.

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Claudia:, thank you very much..