Rust Programming Language Rust and Tell Berlin, 9 Oct 2021

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From YouTube: Rust & Tell Berlin September 2021 - Bastian Gruber: Learning Rust - One tutorial to rule them all

Description

Book: https://www.manning.com/books/rust-web-development
Code: https://git.sr.ht/~gruberb/onetutorial

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(Closed captions, provided by prisma).

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[Bastian gruber], so I did some little side projects over the last few months,, just some of the little helpers., and I figure out this might be a nice way of actually like learning the language.

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So I created like a little repository and have some guides,.

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12 or 13 steps.- and this is what I'm gonna present to you- today.

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So my name is bastion.

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I created this meetup in the past three years, ago,.

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Or I started this meetup three years: ago.

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I worked as a rust engineer at a company called kraken,.

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The digital currency exchange for people in the blockchain world might know about it., and I was part in the past of the async working group.-.

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And now I work as a solutions architect at a company called twilio., it's a communications platform where we can send text messages,, voice, and video email through their platform..

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So if you get a text message from like netflix.

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Or your cab driver company,.

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This most likely comes from twilio., and I also currently write a book, like with manning,.

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Called "rust web development.".

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You can pre-order this book., it's not out yet,, it's about 60% done..

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I hope I finish it by the end of the year.

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and this book is meant, as you just heard,.

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That prisma is looking for like rust, developers.

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This book,, if you have... yeah,, that can wait a little bit longer..

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It's a great way of picking up the language.

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In a web context., so if you try to apply for a company in the future,.

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This book is tailored towards people who want.

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To pick up the language and do some practical, project.

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So I'm not like a language guy., I'm more like a practical person., so this focus towards people who want.

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To have like a hands-on experience. so, like you, won't learn from this book. The best way of like writing like rust code,, but you learn how to deploy and develop code,.

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Like with the language., and for also, if you work in a company, and you want to onboard rust, developers,.

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This might be a good book to hand out to your employees.

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Oh yeah., and there is like a website,, obviously like you- can buy the book,, but there's also like a website called rustwebdevelopment.com.. I try to write in the future little blog posts about it,.

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So we can like learn piece by piece.

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But now about the talk,, this is about the onetutorial.

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This is on, and I'll show like the website. Later.

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So this is meant, like I scratched on an itch.

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Where I'm a freelancer or like,, I was mostly like a freelancer for the past five six years.

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As a freelancer,, you don't pay into the retirement fund per se,.

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So you have to handle like your own money.

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and as it goes, like with like developers,.

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Like you have like different income streams through like investments., I just centralize them all into like a google sheet,.

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But I don't want to constantly update them. and it's also like important for me to know how long does my money? Last until I run out, like when do I need to look like for a new project?, so I build like a google sheet, which collects all this different price points from different endpoints, and updates the sheets,.

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And sends me an...

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and sends me an email each sunday with the latest stats,.

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Like when do you run out of money and how was the week.

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And like through the process of having the small tool,.

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I thought this is actually quite nice, since I crossed like a lot of topics you would cross.

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In a bigger project., but the code base is so small that it's easier.

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To reason about the problems, and it's easier to fix, them.

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and therefore,, I thought, yeah,, like let's form this into a tutorial., this being said,. This might be not your jam. like you might be not into finance or something,, but I find this is also great.

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Yeah. like for example,, I have like my read it later: list.

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You can build like a chrome job,, which goes through your pocket list and deletes the articles which are older than two weeks.

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So, like this forces, you like to actually like read the stuff you save.

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So this can be adjusted, and I go after the talk, or after, like the last slide,, to talk a bit about how you can adjust this.

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So here,, like you, say,, like it's about, or here you can see, this. It's about 399 lines of code.

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It's like eight files.. You can do this much, much simpler,, but I fleshed it out a bit to touch a bit on more broader topics.. So you actually face some troubles you might have to fix,.

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Which, then, you can learn about traits or like locking and all of this stuff.

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And, like the nice part is,, since I'm not a person who wants to learn a language for the language sake,, I try to build stuff, and I don't care about like the language,.

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But this is nice. Instead of building the 10th to do app,.

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Or like, something else, like it's nice to have something in production, yourself,.

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Or like in production, means on your own server, or like a, yeah, like a digitalocean instance.

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Or something like this.

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So this is the tutorial., it's 13 steps and you don't have to route, like read through, like the whole of it.

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Since I, yeah,, like worked in the past at a crypto company,.

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I'm interested in some cryptocurrencies.

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so like,. This is why this is tailored towards this stuff.

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So this is basically like,. You start with an http request,.

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And then each step is building out a bigger and bigger.

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And more like useful application., so like first,, like you, just send out like an,.

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An asynchronous http get request,, then you try to actually fetch something from an api.

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Instead of hard coding, the api key, try to put it in an environment, file,.

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Then print it out like nicely on the command line.

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Instead of hard coding, this, try to have like a cli application to pass the arguments.

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For your api call., then you can save this in a csv file..

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If the get request returns, something you don't like,.

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Try to build your own error, handling.

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and like... and, like a logging, mechanism,.

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In addition to crypto at another http request to an etf,.

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And then like,, this is also obviously up to you,, try to store this information, or update this in a google sheet.

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and..., and then you have like a nice amount of lines of code.

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Like you might have maybe 200 lines of code,, and now it's interesting.. How would you split this up? and you wouldn't do this if you build this for yourself,.

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But it's a nice way because it's a little,, I don't know,.

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Like an application of 200 lines., it might be even simpler just to keep this in one file,, but it's a nice training. try to figure out how,.

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How would you split up this code, and learn how to work with different, yeah,, like modules.

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And then, since I have like a very cheap server, instance,.

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I try to build this code onto the server.

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But the building,, each iteration of the code,, took like two minutes or five minutes. Sometimes.

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And then I figured,, why don't I just compile this on my machine, and try to push it onto the server?.

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And then, of course, you have a problem with this doesn't like run if you compile it on a mac,.

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Or on an, on a,, like a different, yeah, like linux, distribution,.

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You have to figure out how to cross, compile a binary,.

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Which is interesting, too. and then in the end, you can send out an email to yourself.

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With all the overview you just saved,.

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Which means you also learn how to send an email from rust, code,, which I think is quite interesting..

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I want to go into like a few highlights., so like this talk is not super structured,.

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I just want to try to touch on a few things.

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And for,, I think, like a few, people are completely new to the language, or they try to learn the language,.

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So I think it's quite nice to go through with some of these topics.

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And it's..., so you can find the repository and the,.

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This, like I use as a sr.ht.

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For my git repositories.

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And, and yeah,: that's the tutorial.

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I have the solutions,, I try to write like more texts,, but I just became father for the second time, like four weeks ago,, and I definitely don't have time to do much. Stuff.

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So I try to fill this out, like with a bit of interesting topics. You might face,.

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And how to solve them,, but each of the steps have their own branch..

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So if you click on this,, you actually see like the code, and yeah,. The log file is in here too,.

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Which I might have, shouldn't have done,, but here, like you, can go there and see the result.

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And if you go to like the second step, so for example,,.

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In the previous talk we talked..., or there was the topic about, yeah,.

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Like runtimes and asynchronous code.

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And here you see,- and this is basically a copy paste from the library,.

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From like request,, which uses the tokio,.

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Yeah,, like runtime in the past., the nice part about this tutorial was,, since, in the end, it's 399 lines of code,.

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What, if you change the tokio, like runtime to,,.

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To like a different one? and like,, what would be the... and yeah, and like what would be the impact of the change?.

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And I feel like in this amount of code,, it's actually quite nice- to try something out.

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So like with this code, base, in the end,, you can use this in your job when your colleague says,.

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"But I use this library for this case.".

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You have like a running code base to try this out,.

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To try new, new yeah,, like runtimes out, or new libraries out..

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So this is how an http request would look like.

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With the library called, yeah, like request.,.

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I think it's quite nice to also see from people from other languages.. That's quite nice that you can just do like a dot json,.

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And then you have like a, yeah, like a json structure.

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In this case, we pass, or like,.

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We assume that this is a hash map of a string, string,.

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And if you open this in the browser, oops.

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It's pretty simple to see the structure.

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It's a string and a string in a map,.

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But,- and we come to this later.

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in the second step,, we do, hey,,.

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Let's fetch something real from this api.

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And then the question is,? How do you structure this in your code, base?.

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For example,, if you check out step two,.

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I hope I still have my...

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Yeah,, let's see.

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Or just copy paste, this later.

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for example,, if you would run this now, and we see here,.

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I usually don't work on a macbook,, so I might be a bit slower to handle the stuff.

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I think this has everything we need..

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You can see the api key. it's, no.

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(bastion laughs), sorry. (laughs).

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Again, I prepared this whole talk on another machine.

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Bear with me real quick.

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This is just a trial api, key.

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So I can just copy this key.

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And then put it in here.

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So the nice part is, what I want to show you,.

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Is how would you go about in your first step to integrate an api.

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Let's say your company wants you to fetch some information.

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You read through the documentation, and like,. What is your next step?

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(student answers? Quietly) [bastian], yep.

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Nothing here works too.

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and let's get this in here.

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You see my api key., so like,. What would you do like with this information?.

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Like you need to build an application, and then you get a whole amount of tech, spec.

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It's here,, you see it's building.

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And then you get a whole amount of like wall of text back., and how would you go about to figure out how to build your structs and stuff like this out of this mess?

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and a nice tool for this...

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I don't have it here..

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There's a, like a website called transform.tools,.

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And you can pass your json, and it spits out your rust structs.

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Which is quite nice., and I think this is not valid json,, so I don't know how I tried it in the past.

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what you can do is then obviously,. If this is...

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(Student speaks quietly).

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[Bastian] adjust with... (student continues, quietly).

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[Bastian], this might be it.

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And then you can paste this here, and boom,. You have your struct., so this is quite nice. and with rust, you don't need to do this.

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so for example,. In this example application,, I don't care about the status. and you'll see like,. What is the status?.

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I dunno where the... here, like all of this stuff,, I don't care in this case..

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So it's important to know that you don't have to have the field.

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For every return you get.

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Okay,, I can't.

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we'll do this, and we can move to step three.

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Nope., let's say step four.

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here,. You see that I just have like a data.

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And the data is a hash map of a string.

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And so, and I, and I'm not interested in all.

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Of the fields this api is giving me back., so like, you don't have to for example,.

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In rust, you have the option type,.

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for example,, like where you say, option,.

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And then I don't know, string or something else, and you don't have to do this.

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like you, can just say, "I, don't care," and that's fine..

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And all of these steps,- and I don't want to spoil this too much for you,, but all of these steps, I feel like they will help you, since, if you join.

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As a new rust developer in a company,.

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There's so much,, I don't know, like new stuff, that these little things should be in your,.

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I don't know, like muscle memory,, because this will help you later on.

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Just to do the actual task and not to think,, how should I do this in rust? and I feel like this tutorial covers all, all those basics.

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We, for example, see, like,. If we want to print this now,.

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So we have now like a currency.

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We get this from a hash map,, which is...

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This for example, and we want to print out this, this,, this currency,.

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Since in the tutorial, it says, get the name,.

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The symbol, price, and 7day of bitcoin.

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And stored in a struct,, it doesn't say to print it out..

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I have to do this. but let's say like,. You want to print this.

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And there's no way that rust knows how.

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To print your own personal struct.

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and there's this shortcut,, which is yeah,.

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Like debug, and you can add the debug, and then you can print out a currency., and we just saw this from the helpful like member here,.

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That you can print it out as like a debug, debug formatter.

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But if you want to do like the display, so like this would work for example, for, like numbers,.

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And this would print out six. and rust knows how to print out a number..

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But rust doesn't really know how to print out your custom struct.

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and if you want to have like the display, you have to implement, or like one way of doing it is to implement the display, trait.

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and this,. You also come across quite often in companies,.

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That you have to implement traits onto your own...

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Yeah. on your own custom structs.- and this is actually quite simple since all of this obscure thing,- it's just like a standard way of, of implementing this trait.. All your custom stuff is actually just this here.

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You basically, and like the right,, this has to be here, and the formatter has to be passed,.

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And all the rest is up to you.

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So like, you can also just for example,, say bitcoin,.

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And I know people here have very strong opinions.

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About this stuff,, so I don't want to overuse this word.

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For example,, like you, can do this.

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And you can, because...

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yeah. and then, whenever you want to print a currency,.

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And this can also not be bitcoin,, then this would be in every print. You print.

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For this type of currency.

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so- and this little thing is quite good to stumble like against, and figure out, why can't I just print out my custom type.

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So like we covered this, and then the question is,.

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But I want to not always have like a fixed amount.

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Of currencies, I want to deal with.

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and then like. The next step, is to build a cli.

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and, if you think about maybe other...

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I have 7% left, and then the talk is done. (laughs).

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[Audience], do you need a power cable? [bastian] yeah, maybe. yeah,, but this also forces me to, to be a bit faster.

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If you,, I think I have one,, but if you have one too.

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[Audience] usb-c, right?, [bastian] yeah. (audience speaks quietly) [bastian] perfect, thank you.

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Where was I?, oh yeah., like cli apps., so, like you, would probably google cli app rust and see like what's up there.

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and then at some point in your research,.

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You would come across clap., and this is like another beautiful thing.

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Of how easy and fast it is to build a command line, application with rust.

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Say like the reading is always a bit of a scrolling down, and the speed I actually broke today, my talk,, so I have to revert it,.

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But basically we can check out step five.

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Does this work? yep.

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No, miss it, step six.

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Yep. so here, how, how, how clap works for clap,.

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Is you basically give them a few information.

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You create a new app, and then you can specify arguments.

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And the next interesting thing is: if you want to pass a file,, that's one, one argument and you pass this,.

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But what if you want to have like a list of like multiple,, and then you have to go through like the documentation and figure this stuff out.- and I have put this in since a lot of like rust, work.

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In your beginning will be to read through the docs, and clap has quite nice documentation,.

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So this gives you like a first taste of the, of the,.

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Of the ecosystem.

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and you can say,, I want like at least one currency,.

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And then here we already write the csv file,.

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So it was actually in step. Five,.

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And then we can skip a few.

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So here, for example, you can now do cargo run,.

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And then, like the next point, is,, how do you actually run this with cli? and in the beginning I tried to do like cargo run,.

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And then I passed the currencies, and then it didn't work.

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And I had no idea why. and then it turned out that I have to do this, and then it actually works..

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So here I fetch bitcoin prices.

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Until my api limit is reached, and here.

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In the next step,, we will see how to write a csv file.

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This is also quite interesting,.

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Because this also gives us the option to pass like multiple.

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So let's say now: we have this,.

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And now we go into this stuff,.

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Where we see oh, I'm on beta., so I shouldn't be..

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I changed the version number.

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This has to work, not differently.

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Oh,, all of this stuff is live., and you see of how, of how it feels like.

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In your docs,, like you can choose like the version of like which documentation of the version you want to look.

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And you'll see that they changed this in this newer version.

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And I think this is also different.

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And then it should compile again.

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And all of these processes like to work like with the compiler, and now my environment files are not there.

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You will see like with rust that you will for 90%,.

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Especially in the beginning, and later on, maybe 70% of the time, fight with the compiler., and this has to come and it's not a fight.

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That's a dance. and that's, that's,. That's quite nice.

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And you learn to like the compiler. for me was I had my first like the rust job, and then I had to switch again,. I think, to node.js at the twilio company.

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And you suddenly feel that something is missing.

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Out of your life. you're like,, you really feel that,. How can someone just like write and don't have this compiler? and here,? Like you see, now we have like a csv file with the arguments we passed, and this is quite cool.

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and I feel like this,. This is already so much fun.

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And later on, in the later steps,, if you go through it,.

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You learn more and more, until, and I don't go through like a google sheet. Setup,.

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But I want to mention two things.

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First,, I want to show that it actually works., like I have here this sheet,. This example sheet with, like crypto and etfs.

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And if you go to the last,.

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Last step,, you probably need to have they...

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But nice, it's already there.

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so now you can do cargo run.

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And if you do this, and you see this spreadsheet here,.

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That it will be updated, hopefully.

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(Audience speaks quietly), [bastian] yeah,, that's already,,.

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I need like a desktop replacement.

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And you see here, like it's updating like the prices., I have some... some debugging logs here.

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And later on,, I will fetch here, like the sum and this stuff, and send out an email which should have happened.

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In the logs somewhere,, but this is how nice it is. and you can think about,, maybe like you, use like a bug tracker in your company,.

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And you're just, and you use three, four different tools,.

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And you want to,, I don't know,, collect them and also like,. Let your business people see,.

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I don't know, like what's the current status of the product.

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and I find that, that the, yeah,, like the google sheets.

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Has quite a nice front end facing database.

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For stuff, like this.

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What's powerful with rust, I've found, is one thing where for example,.

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Now I want to send the email, out.

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And now the question is,- and this is quiet or like some nice problems to face.

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Like you have like an email type,, but now the question is,.

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Should the email type know how to print out the dashboard.

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Or how to print out an etf, or how to print out like a crypto, coin?

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and, like you can say, yes,. But you can also say no and say the email is just calling a function to html.

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On the type and then sense of the email.

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And for this, like rust, has a traits,.

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For example,, the email type has a trait html.

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With the function to_email_body.

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So now I can implement this type,.

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Implement html for coins to_email_body.

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And here I do like an html table,.

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And I do the same for the etfs here.

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So now the type knows of how to print an html body.

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And the question is now,: how do you pass these types to email?.

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And I found this quite nice, and I don't want to spoil this,, but maybe I do now, like how do you pass an array of different types.

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To a component?- and here it's also nice- that you basically can create a vector of types,.

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Which implement this trait.

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so for example, and here,? The compiler is nice too.

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If I would remove this trait from coins,.

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I don't know why there's an arrow, now.

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(audience speaks quietly).

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[Bastian] or I have to remove it, eh?.

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Nice, thank you., and now it says, hey,. You can pass this, since this is not implementing the html trait.

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And this is beautiful., I like this very much.

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and then you can say that each of these components have to implement this,.

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And they have to know of how to form an html body.

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It's not up to the email, type.

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and then inside the email,. You basically push this tool,.

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Like an html string. and on each of these components,, I pass off coins .to_email_body,.

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Will add to this body string.?

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I return this body string, and then I send out.

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And this can be done in,. I don't know, like a million different ways,, but to face these types of problems,.

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It will like lead you down a path,.

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Which we'll face later on,, I feel like in your production, environment, for,, for,,.

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For like a random company., so like, you don't have to make it as complex as this,.

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But it's nice to make it complex as this,, because then this leads you down like the good pain, path.

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Like I always say, like, there's good pain and bad pain, and good pain,. I don't know, like it makes you grow, and bad pain,. It's just suffering.

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and I feel like these types of problems are good pain, because they make you grow.

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And the nice part is here,. If you go through the code,, it's not super complex., and now you can say, what if you want to use async_std?.

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I don't know if this works. like,, obviously not, but like,. What? If you want to change this? what would break, and why?

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or your colleague says, "we, don't want to use clap.

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We want to use something else.", they will probably never say this to you,.

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But let's say like,, you don't want to use, yeah,.

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Like request,, but something else., what if, and I use like a logging library here, called...

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Log4Rs. and what, if you want to try like a new logging library.

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In your production system at work?, this is the perfect playground to try this out and see it in production, and then see of how it feels like.

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so to not to make it too long, feel free.

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Oh yeah, and this compiling.

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I just spoil this, like real quick. like,. If you want to cross compile,.

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You have to prepare your hosts setup in a certain way.

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I think I also link to a really old blog post,.

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But which basically like, explains like what you have to do.

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You can add a target to your rustup toolchain,.

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Like this. and then later on, like once, you've done this,, and I think I didn't do this here,- you can do...

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Release and then target., I don't actually know target., and then you do this here.

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and then your host, and this doesn't work since I didn't edit it yet, or...

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Jesus, like what is cargo?, this is embarrassing.. Cargo...

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(audience speaks quietly), [bastian] build.. Thank you so much. (laughs) yeah,. This doesn't work,. Since it's not set up here on my mac,.

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But then you can basically build a binary, which is statically linked to,. I think it's libc,.

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And then you can push it to like a random linux. Server,.

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And it runs there., so this tutorial will lead you down this path.

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You might not have to follow this whole path.

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For example,, you can try different...

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yeah., like refactoring stuff., you can,. Instead of storing it in google, sheets,, try out different databases.

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and, if, like finance, is not like your jam, try to collect information and send out emails.

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Like it was quite nice since, after like one or two weeks,, I forgot that I wrote this job, and then I was on sunday on my couch and got an email.

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From my own application, with information about my stuff,.

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Which is quite nice.- and I feel like this is quite nice to have like a running like rust. Application in production.

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For yourself to learn, stuff.

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Okay,, that's it.! Thank you for listening. (audience, claps),.