Rust Programming Language Programmieren in Rust (Full lecture, German), 4 Jan 2017

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From YouTube: Programmieren in Rust (04.01.): Makros

Description

Vorlesung „Programmieren in Rust“ an der Universität Osnabrück im Wintersemester 2016/17.

Dies ist die Aufnahme des Beamerbildes sowie des Notebook-Mikrofons. Alternative Aufnahme (mit Dozentenvideo): https://video4.virtuos.uos.de/engage/theodul/ui/core.html?id=8d44d64b-ac8b-42e0-80dc-223f83ba9745

Slides und weitere Informationen: https://github.com/LukasKalbertodt/programmieren-in-rust

Playlist: https://www.youtube.com/playlist?list=PL0Ur-09iGhpwMbNiVTBeHmIjs0GuIXhNg

A

Welcome back after the holidays enjoyed at least big community had a bit of fun, so pick you up from the holidays and pay a little. What happened here shortly before new year's eve? Who of you uses reddot regardless of the question who knows save me, only has one user interesting, but in any case there is a washboard and somehow it was just before christmas was just before new year's eve. There was a lot going on and everyone was somehow a bit stressed.

A

That's why sometimes wildly thought, then the rule that you don't post any news about old, stupid, simple wippermann appointments was dissolved, those are from the internet and you shouldn't actually post them, and then it's totally agree would then be kept for two days before new year's eve and unfortunately, I ca n't, look it up anymore because they were all deleted because they were hidden. That means I can only do it now.

A

I happened to see a handful of posts that were still open, but I wanted to briefly show you a few things about this great bobic and then someone else who was a fan of west side story and rast also did something small moment. It 's the question of whether I manage.

B

C

A

Think that here I think, it's enough to shake you awake a bit. There are a few other videos from side story, so you see people were very creative and used the holidays. Well, and today is about markus. But before that I want to discuss the tasks with you again, because there were a few problems there. Sometimes they weren't solved perfectly. They were always easy to understand.

A

Of course, if you want to celebrate christmas other things, but we always go all the way briefly, so that at least everyone is on the same level, because there were a few things that were really done wrong by almost everyone and I just wanted to address them.. These are the.

B

A

For this week, by the way, I'll upload them after the lecture, I thought to myself, there's no point in uploading them before the lecture, because that's what I'm going to talk about today,, so in task 1, it was about getting this funny step, blah blah blah working. There was his task in it. Yes, you should just do it somehow that 's in too order.

A

Nevertheless, I would show very briefly that you are the only thing or whether you might have been able to pay attention to it, and that is, first of all, from behind you dare to do an extension trade that we have done before simply to get an integer with methods to start from, in this case this times method just that still an old version. It's not the perfect but important here. That's the only thing that many of you wanted to get at with this news written on fm. Why should you rather write fm news.

A

So fn is a traders restricts more,, just like copy and clown püppi restricts more, type. When we write a news, then the user can, for example, change according to his environment,, so it restricts less what the user can do that’s why we want to have that, in most cases we want to. We write it in the news instead of it, nsn really never writes, and if you even do one thing only once, then you made it, but otherwise.

A

There were only two buttons.

B

A

Think when shooting, I hope, by the way that my wrong tests in june don't cause too many problems. Somehow they had a posse tory for an hour or two at most, but they banged a few and were quite disappointed when the young testers said no that 's the problem. I have my june test, which should cases I just wrote in which I ran my own algorithm, which was wrong. So you shouldn’t write a jew test and it should be best somehow meaningful stage win whatever.

A

Then those are all the tests. We are still.

B

Accurate I’m.

C

A

Like that either I’ve got myself a bit: fun allowed, I don't know, had a short meal or really complicated algorithm built in, namely mixture of war and concessions. Location is really only important. That's just the implementation think here the three methods that should implement there.

A

You can find out somehow that there, with the general sste is so most of you are also recognized and have written the actual algorithm for your sword in that's also right, I've outsourced it again because it's so big it doesn't matter- and here you click a film with ryan, the two somehow references from these elements comparative north back. There is again in jud profile. Can I make sense that it is in jud.

A

Very small example: one would like to count how much compensation tuned in certain socialism needs. You surely know this sound of thing or something like that. You have these funny things. Computer science or these funny bars sort themselves, one after the other, so that they then form diagonals such things. You can do with them, for example, and count the four comparison there are. Then there are swords for that. Long, trapped that the place is, and then we can just do.

A

This here, this method was handed over directly by the rott trade, so a functional building, so to speak and with short kia knives. We did something wrong and it's about the fact that we can also return a different value than what our t is in the rating you can see here we have three templates parameter, 3 type parameter, then still this normal rey with ts in it, then we have this function f and the and a a reference to tee and map that to a new type k.

A

This type can, of course, also be tee, as in a test below that can also be tea, so the same type again where it can also be a different type, think about it. We want to sort an eray from koppl and we want to sort that according to the second element, or we have students and want to sort them according to the matriculation number and dormitories ray inside and say as a place at kiep and give get his reference to a student and give back the matriculation number.

A

That means our article naturally has a different type than that doesn't have the type with student, but it can be sorted by ours. We can then sort it so here it went in any case. It's about the fact that this plaintiff returns another type and not clear so far so clear.

A

I hope it wasn't too much then, over the christmas holidays,.

A

Then we'll continue with this great topic, I thought to myself where we only got a handful of profits. We can have an appointment this week to.

A

Talk about macros on this topic that may not fit in with us completely,, but I do n't think it's absolutely necessary, among other things,, because you do n't use markus that often, some may disagree,. But I think if you want markus to often want me to understand how you read them,, you can understand what they do and basically understand how they work,.

A

So, let's get started, and we might first ask ourselves why you have to have a function,, for example, and banks are now not printing as functions, for example,, and so we take a step back and think about programming, yes,. The main reaction at all is we still want to somehow abstract from.

C

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Various reasons,, for example, doubled from 160, because there are a lot of disadvantages, one driving the more or copy more or then also the problem that if we briefly change one piece, we forget to change the other, which should actually be the same. There are somehow inconsistent inconsistencies between the chaos. That's not good either, but in particular, this abstraction will also be better. You have to.

B

A

Box abstraction. That means we think we had something like an algorithm in a black box, and then we can forget everything about how this algorithm works outside of our heads, because our heads are hanging and can't hold so many things at once,, e.g. make we have such terrorism and as soon as we have described the rhythm, we put it in a black box and we know we'll put an eleven in it and it will come out again, but we do n't need to know anything more about socialism and can concentrate on our or other tasks.

A

Of course,. That's the right thing to do when programming, that you somehow create life in the abstraction and can work in an increasingly balanced way and no longer have to work at the machine level or even push the electrons around what you did exactly and almost always semantic abstraction,. That means we somehow have it. What most languages know we have to have the system they had normal variables to handle other things like that we notice, but sometimes it's not enough. That's why these microns are tactical abstraction. That means we just.

B

A

At the source code and build abstraction from it, we build the abstraction for you over the plain text over the text directly. It has some advantages, e.g. previous options, because things balance it out. We have already planned the tri market that we somehow can’t do with functions, but there is also a disadvantage,, for example, that you can use difficult ones about. It can say things so if we are only.

C

A

Text or yes, abstract tactical things that is more difficult to pull out because.

A

We are about semantics if we said yes, a type that can be sorted in some way, then it is clear the compiler would say there is, but not sorted in all of them.

A

If we're just saying we'd like to have a word somehow say a small computer, this word does n't fit told how doesn't that means. The compiler can also output. Worse errors, it's really stupid with matthäus. Exactly so. Somehow markus also has many disadvantages, but is more powerful and the example two more had already seen.

A

We have the problem that we will write for your dance whenever you want to have a website. We have a return in case of terror, and if it is ok, we just want to return it and use it, and because I know Not whether some of you have tried it,, you can no longer do it with functions, abstracting it.

A

If you have a function,, it returns it,. You end up exactly where you started,, so you simply cannot save yourself. This quote, and there is this writing we have the solution where I already have the definition for a moment, but we should take a closer look again and we'll see exactly how it works. But it's important- and that's also mentioned again in ra's book, the markus and somehow the last one way out.

A

So if there is any other way- and it is best to use other abstraction options that we already know, we should not just write markus because we find the exclamation mark expensive under anything else. So we should use the semantic abstraction, if possible, somehow to get better errors,, among other things, to get men so and now there's a small overview of what marc that's all there is and that's quite complicated as it turned out. It was quite a while until I had researched this overview together, we'll see briefly.

C

What 's known now.

A

This function is easy, markus hofmann receiving the.

D

Brand name names.

C

An exclamation you.

A

Then somehow show a function only with an exclamation mark and there is in particular the subclass marco, bayer, the entire markus. We will see in a moment. We will define the exclamation mark with marco hüls that’s how they work, but they are right limited. They are also very powerful, but quite limited to what I will reveal in a moment on this slide, but it is important in any case that you stay aware. That means they run on our current compiler and they work, and then there is still in In this case,.

A

There are also the presidents, who are also a joke, obviously,. You call them like that,, but obviously,, the little markus babble,. It is, then that we have come to a larger class of things, and although they are extremely already there,, they are all still there function markus inside and that belongs to a different class. These are the compiler plugins that cut through, like that, and it's a bit complicated that resulted in the saying, but are there briefly throughout this sunday extension just means that they somehow and the song texts language? What can.

B

A

Marco by example, but these goals markus they belong to the class of compiler plugins. That means we really write. Plugins for the copier itself sounds complicated and it is more or less so. That's another one thing.

C

A

We are not going to make this change either,, at least because it is very complicated and unstable in particular,. That means you currently need a home manager compiler to use it simply because the breed developers have not yet agreed on a fixed ip and that’s. Why? Because you don't stabilize it yet so that things don't break later, do n't rely on it like that, but a few other things will come up and say that it fits and who knows this attribute, you already know the rice and then something that you can write about.

A

If you want, you can do things yourself with these compiler plugins,. The mature recognizes that he for amaze and debug and anything else that you could also do for your own trades or for whatever you want. So you could somehow do everything so that you can.

C

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Any attributes after that, you can write any attributes somewhere on it, and if you have written the appealing, compiler poster and registered it, then you can do something with the attribute where it is due.

A

We will see a bit more of it at the end of this lecture, what it is all possible and then that funniest thing you can't imagine right now, if you somehow have an internal compiler basis that you can still run through. That means you might really compile an aging process and go in at some point and do something with this abstract representation of the carport for complicated and that's not suitable for people who have never borrowed anything from compilers the hole that you similar. We only care and to cuba.

A

So now that was stable, that what you can already use today, so that will be at least the first half or a large part. This lecture has to become its whole, as said painting course, look at that this compiler plugins can we know where we stand. So, let's go to eco by example. That just means it now has a special.

C

Meaning and the.

A

Image, syntax, trees, abort other intercitys. You could almost imagine that maps any text onto any other text,, but syntax trees, as it turns out, is still important that it is taken into account.

A

For say times addition stood and he then had two children, two nights. The two victims then ran with a child, for example, again.

B

A

Genetic material situation had two children again and at some point a child is, for example, a writer. So a number directly and.

B

Such trees, such syntax trees,.

A

Are also built up for all programming languages at some point and that they look much more complicated. Then you somehow have a node in.

B

A

Tree that is called, don't know, tract, and then there are somehow other children for all the fields of the tract,. So for this, the type parameter and all such things, well, there are clearly more complicated trees,, especially if you imagine a function,. We somehow see that we hold several expressions for several statements and specials,, like other experts, do, and so on, and so forth, so complicated helps,, but in any case,. All of this can be done as a tree. Imagine that will be michael beck, see you again soon from crete.

A

Then it's not so scary, it's important, but that there's no pure text replace it like with 10, we'll see an example of the problems that can occur in abc marco already mentioned. That's just a keyword with which we define it, and here are normal. First, marco schreyl, marco russ exclamation mark then space and on our name that we want to use, and here it's first completely empty definitions.

A

That means it doesn't matter, and they can now also call it like a function that does n't do anything like that, and such a battery consists of a series of rules, roughly recorded.

A

It looks as if marco russ bracketed his name and then a series of rules first in rounds, then with a hash rocket like that, so easy, draw, bigger and then somehow bracket the bochums, but we have several options that are similar to match, but we also have them, because we don't just see examples and we quickly notice that Sunday thrillers are not about values, but about screens- and this call the I was there I already mentioned- it actually means experts. This call is not like a function start because we didn't call anything at runtime.

A

It 's just that the compiler once it runs past this marco expands. That means it looks proved that marco defines and instead of the macro call, it will say how it will be, so it will say replacement of ten taxis, and now we see our first real example, so we were describing a war market. That is absolutely not yet. What markus are useful for?

A

You could also use the function, no matter whether we are here in our left arm,, for example, with quasi by registered mail, just and then we can also write down the right side in this shop in brackets on trink, and now we have a second possibility, sabine is given it, then it's just somehow another body, and that can now also call like that and that works to support the compiler. It's your time, that's important different from the match too complicated.

A

He looks for the right arm out the right now match and with this arm and now puts here at this point the latter rinteln. So he replaces that, with this everything you stand, transfer from super street so and important animal companion token compares that's something that has denied me for a long time and we'll see what kind of dead people there are, but rather one thinks one way or the other. What do we see there? We had the topic we just assign peter a name to enter a country function you would expect now.

A

Is that exactly the same would happen, but that now leads to an error, because we are only interested in the syntax it is given on, and here we ask for the syntax that it is a string literary peter stands here. Chancellor peter stands somehow an allgaier it 's wrong.

A

Let's take a look at something right that we're short, even if all tokens or almost all tours, are allowed this strange, syntax matching. If we have the disco striker marco, we can really just write everything in lowercase, three percent, it's kind of a number and then an operator or keywords like that vsm. You can just write that in there it's not quoted by races behind it so that problems arise. I think so, and there.

C

B

Call it just as well.

A

Just write exactly that in there exactly module he character, so we.

C

Can insert characters everywhere.

A

Also words, of course, but normally the bar is not important as a separator. Also that could still call, and that brings both what we expect here must be free. That's what I just said. The only restriction is that both the definition and the call here the brackets have to be mixed,, I.e. they have to be balanced, and you can't bracket square brackets without brackets all have.

C

To be balanced,.

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Somehow its the case here so far, that's fine, but that.

C

A

Doesn't work if we enter something there as well? The error comes, this is probably not expected. This dead is not expected here with.

B

Anna, that's.

C

Still fine by michael.

A

Kaiser, but it's almost not at all, that's an extremely good example. Now that does n't help at all. I wanted to show and show that you can really decide all the dead big now it gets interesting if we don't just write constant things in there, but if we somehow have variables and give for them so-called meta variables, meter variables are now different than normal variables that bind a value to themselves. Meter variables, plans, syntax baumann, write themselves, a certain syntactic form.

A

If then rested again, and we have this funny normal, that's just what I'm doing there just like that write in that he has no special and iphone special meaning. This dollar.

B

A

That says here you come a meta variable, the Hessen name and is of the type or therefore tactical for mac such an explosion. I have a second one that looks the same, and now I can.

B

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Here say: tyler bouck, again notes for token shape that fits here. That's just one to one with the colon fits. Then here is a writer again compiler and compiler professional roter stream material. That's an expert, then so this first this first evening, finance marco fits wonderful. So it works as you would expect, and here you can see a definition of this market- just use this sampras variable with the dollar sign, but we can also switch on something like that, because this is also for the chorus alone experts that quite.

C

A

That his explorations and then this this sunday language you used here, will be replaced as a new one, this after the colon, this extra that you can syntax opening ceremony. This tactical formation is just an.

B

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And which again has nothing to do with the type system, so this the whole thing expression that results in a syntactical form in this case, if we just go into it now that, of course also an expression, you get a very good error message that says widely implemented, not display, but there could also be a much worse error message because it actually comes like that. He knows a lot.

A

He only knows ok contradict demands and in marco something is done with this expression, then it can often explode in the month before and he was expanded from the character. Only this one macro body there is now an error occurred, not so nice, but a A few examples will be.

C

Asked if I would now give a function to it that changes something so these pages like it I, would click twice within the market. Would then these changes be made twice, or does this page finally appear on the wall? Will this expression evaluated you.

A

Can not imagine that when we write the cover letter, the first time is replaced by blinking sa pobla and informa place. These whole six.

B

The principle then arises.

A

Here and in this.

C

A

Be evaluated once now calculate if you would use this expression twice, then it will be executed twice, but that's the way it.

B

C

A

Has nothing to.

C

A

With the type system, your marco, you can write everything first, you can imagine that, because it is very expressive, just one variable that cannot be copied. I could give you two I could use it. Then he doesn't like it for the semantics behind it for the mark of an explosion that is used twice only when the macro has been evaluated then, according to the definition it is, then the compiler sees this name that we put in there. This variable we twice used, but that is one without a chip error that you don't get used.

C

A

We'll see more examples halfway into a great example actually to friends situation, you might know, maybe ultimately happy trade. That means 100. It describes types of which you have a sensible standard instance can create without.

B

A

Parameters so, for example, do n't know from beckdorf. There is somehow only one sensible standard instance, namely a teacher vector, and then there are several types that already have structures that don't accept any parameters: eg friend origin, if a guarantor for one no parameters just returns, the point to the origin and fibonacci this nitrate, and sometimes.

B

This method, or.

A

Functions are also written and they do n't take any parameters either,, they simply initialize it with 101, and this is somehow calculated so that we implement the default but may not be hand to hand where which allows us for any guys who already have a constructor who doesn't take any parameters to implement the progress when things get tight. When.

C

A

Write something like that: ok now we want to implement the enforcement for friend so say simply selfridges. So we simply.

C

Use this bridge.

A

Function from this friend to implement the folks that works, yes,, but you could perhaps prescribe them for that, so that we.

A

Can implement it quickly for many types that we have,, such as a fibonacci,, so let’s start, so learn them old woman and we'll think about what we could write in there. We need 28.

A

The two things are now an ident, so an identification. That means just one on the spot, we'll see exactly, but that's more or less a new word taking one variable.

B

A

His participation.

B

A

The other products, and then we can simply write down that there are more intensively demolished working products, and then we can just write that down here. We are just shocked to the appropriate places these meters throw in. That means we fully participate.

B

A

Then it struck me that we can do there is that we simply say these two locals for me, then the first variant, and then that was finished. A second meta variable culprit are the 2 normal names here that we can hand over. So it.

B

A

Then there are questions about it. That's the first meaningful example.

A

Ok, no question then passes on straight away. I hope that is then more or less clear. The problem here might still be. If we change, we also once wrote a generic friend. What about a genetic frank rost said have to write more opel lace, brackets t default friend, lace brackets tee or back also, the women actually implement if origin is executable that we have built once on. If t is zero, if you change, so it's a bit more complicated what we have to write there, so that doesn't work for everything we do now can.

A

But we will see a few other examples later. We can do a bit better, but in any case that would not work for friend t, but that was a good example actually because such markus often come use to write any implementation, the are quite simple and which one is otherwise only signed and where one would repeat oneself.

A

That is exactly.

B

A

An example it must also have in the exercises. Just you put me again- the complete example on the spot around. You can look at it again. What now, with texter season försters are extreme settings. Yes, ever 110 or hut, he used markus ten times, okay, okay, so c, that is just no texts session here can define such a scenario for those who haven't seen the scene, maybe for vincent werner blackbirds, but that's somehow 26 and that's defined as 2 x, iks. Well there. You could also write in function now, but it doesn't matter.

A

We can also describe it as a market what's coming because that wants to get out of here. If we register two three plus your. What do you think we're.

B

A

The opinion that one actually expects two times, 74 cents, one can already guess. Yes, there are ten Russians coming. Why? Because much simpler text is this price, and then this string is replaced by two times this string. We stand two times three four or the application. Advice of course has a higher degree.

C

A

Correctness- and that is why it is only carried out twice three times and a plus 4 and nice are then a bit confusing.

A

Of course you can avoid that, and there are somehow a handful of rules on how to not always get in touch with this markus shoots in the foot, for example,, by putting all variables all weird variables dx here in brackets fact, then it all works more or less, but good fodder for weird results.

A

What you see it looks the same. We have an expressionist here and such a 2 x, iks and probably could already assume that there is now contact and 14 what we assume will assume or what we would expect, because what works with syntax want and not just text replacement. We can demonstrate the test with men.

A

How can the weather be these through migration, snowtrex wars and two are now missing,, even in terms of time and latency, and the one on the left, then obviously the 2 and on the right edge then comes the syntax tree tradition with three and four. This whole thing about this syntax tree would be tied to the tenant variables because we.

B

A

Entire syntax tree once in hand than me, and then we insert this one here. We only have it on the other syntax tree. That means we always only work on the whole are ex girlfriend light on the text level. If you didn't use brackets, it's noticeable that you use this syntax tree, otherwise wouldn't work without markus in rast, because multiplication has a higher importance than addition. That means, if you quote it as a texter brückentag, you would always read 34 twice from it.

A

So you have to use brackets, of course, to bring the correct order back in immediately.

A

I continue the ex-president who already got to know about his tactical forms and I'm going through songs. Very briefly, as I said identifier, that's a new.

B

A

Somehow, what that one variable or what types you could have,, for example, that somehow underscores are allowed and he any letters what you so we expect that the pair these are just identifier, separated with colon colon. So somehow something like that. That's a neater than in tactical form expression. Also already there you ca, n't, say more than an expressionist senses. It's just quite whole a lot there. You can do a lot of things,, including a blog,.

A

We also know that there are block expressions that my blog writes on and then there can be several statements,, but overall, an expert is, for example, by types. These are things.

B

A

That and that's just it many others that you can always look at under this link. If you need them as I said, I, don't think that markus uses them that often I definitely don't know them by heart. I actually always look closely at this link when I need a mark.

A

I, don't know the writers where I needed a syntactic one yet,, so yes, one uses that very often,, namely important,, but here I know I did n't repeat it often enough, at least I would have liked to know that at the time, I'm only concerned with health,. That means I'm going to party somewhere disc and a meta variable of tactical form.

B

A

Then that doesn't mean that it has to exist. Downhill I can write down, some humbug can imagine I just checked the grammar of drama fits. That's, okay, we're somehow separated by words with a double colon. Then it is it's probably a bike that doesn't have to exist. Either types do n't, have to exist or be available under other. So it's only these that are tactical. Before there are a few.

C

A

For which tokens can appear after a certain meter variable that can also be found under this link, because I now do not go into detail that who so special rules some rapport?

A

Okay, one more hint, there is not a problem because you work with normal threads in the marco definition. This call is more only uses. These others are extra. That means, if he, for example, as a good example, let's take marco and a function in the same module and now in this market, just describe the function, food and call the selection more assume they are our modules market of functions that can call the functions directly with the name of the host markus instantiated, another module so called.

A

That means we put this syntax tree from marco in another module. Another module is just the name of the function, the other module knows. The name so doesn't know any functions with this name. That.

C

The problem with.

A

These they are simply always used and have no connection to the origin of the market,, which is why you always want to specify the absolute drivers,, at least in the market. What is public can be used by others if I only use it in my own module am, and that marco is the writer for me to use it for my purposes.

A

I do n't have to worry about it, but otherwise the absolute has to be used, and there is also a special thing if you want to use markus buerger for different trades,, namely this trade variable that stands for the current freight. We don't see.

B

That, in one example,.

A

I've mentioned it several times and almost shown it once now. We finally see the correct original definition of scream from the city library this bit and shown more beautifully than before, and namely three this time look at project sport, it's about how we might just somehow be.

A

Able to use other modules or trades and the market position is as follows.

A

That looks very full at first and that's only because we always use the joy, especially one has to write this craig before this trade to ste when it is called from another world. So whenever you write something, you are, of course not in the spd itself. That means then there is always scd, and then there is the complete journey specified spd until then to ok there, and also here, everything is always very, very explicit, looks a bit and nice, but it's good. If you do it for once, why else shouldn't.

B

The rest confuse I.

A

Think we've already talked through enough about error, handling and again a warning. Yes, you don't always have to do that if you are.

B

A

Small private, markus you write for your module, you don't have to be explicit, and most markus are just little helpers, markus in your module, so that you don't have so many duplicates updated.

D

A

Question works.

B

A

You can actually write the market definition write you right, you can never do any called describe back. Then you have to be clear at some point. That means square and round business works.

A

Okay, we will also be the new example that it is exactly the same when Markus is called then I would now go over to a new part. I mean a small new feature then slowly. It should also make sense what you can do with the market was already doing a lot, but not so much. Our goal now is a way to create a goal simply with content.

A

Manel will tell me that he'll do it that way, but maybe that's just nice and you already know how to do it, because there is such a great macro way out of the city library. I would like to program it now.

A

If that is not difficult at all, and he only needs one way to repeat things, because one way would now be any number of numbers write in separated by a comma I mean, and that works for us first of all, so far so clear and then comes that you burn a bit if we do n't bracket them with the dollar and 1 or weaken them and like we have. That means we want to have 0 or more repetition of an express from an extra and how the bix is . Already.

A

If we write a plus instead of an asterisk, then we want to repeat one or more of this comerford and asterisk means that these are extremely separated by commas. We write this outside of the brackets because we only want to have that between expressions, so we want to have one comma less than the number of expressions like you would write a good list. We can, of course,.

C

Do it like this, then.

A

We have this comma within these of these. Obviously that means we always want trading. So we.

C

Always need an.

A

Expert, an extra one with a comma peter that, as often as you like, but that always means that we definitely have to have a trading course. There is also the small abbreviation that you write shortly after the brackets of the comma and then this behind it asterisk or the plus that works.

A

So we can imagine yes, how can it decide several expressions but formally separated, and we are doing that now for the time being, because by definition, marco reus is still looking after create a blog, the latics write it down right away, and so we can write our values.

B

Of course we don't just get the horror.

A

But we're now building a blog, always managed to cling where we use these things.

A

At the end of the block disinfector to assign on twitter blogs, create youtube director and now we're just expanding these again calmly and things by doing that, write here again in full clarity and behind it an asterisk and thinking about updating or let's just write in what the extraction should be for every pick for every six from home dot call push, and then we give this house to our expression stays behind so that you that can be used with a link, for example, and.

B

Then it can be left as it is,.

A

But actually I got to know the use of square brackets, the command. You can call up any nato that developers want to go under and deny, an old man is just a question, which is idiomatic at the moment. What you do we always want to.

C

A

It away with square brackets, but it would be fine, is also called sees. It fail. How do I.

C

Know when which bracket is idiomatic, that I mean short.

A

But don't quite fit how about the repetition? That's clear for the time being, if you say something else, just before the call on sundays have this hygiene that just said you always use it for big things. That made me very surprised for him for almost all the other things in one line stand and what all the functions look like. That.

B

A

Are unique and for things that create such a complicated object,, let me say you might like to create a declaration of taste together or we would like to somehow make another more complicated objects, a little bit the jason, where you also put the objects with saved, but that's also not quite as clear as it works. But it's not roughly looking for what you want to use that we immediately noticed that we used his wife on our brand definition and can ask ourselves whether the cookie called problem leads if from outside v.

A

There is, then we just set our syntax tree, because a man already existed nv before we switch it on and so on and so forth there. You can now construct a very good example of how it can go wrong, and that also happened made in the rast book, and that too is compared again with 10, markus or ten rechargeable batteries. There is no hygiene pc market. You can get used to it very quickly.

A

If you use a variable in the market, itself, some name that you also have outside,, they overshadow you food and strange things happen,. Fortunately, there is no such thing as rusting.. Every variable with animal names also becomes a so-called geotag,, I.e. not only the name clearly identifies the variable,, but only the name with the context,, I.e. whether it has a variable sv within the next generation and outside of that we are the compiler two different names just because most of them both v, but they are both in different contexts.

A

That's why they can be kept apart and there are no problems.

A

Exactly that leads to the sometimes ugly side effect that we just don't have any can use names from outside. That means, if we want to build a small helper market and we want to access three different variables and we think we use it- is the only way to get this function where I know that these variables exist, we can do n't always have to pass a name to the variables so that marco can access them, but otherwise it makes a lot of sense that we don't welcome weird side effects and weird results.

A

Now again, chapter outlines book. This chapter.

C

A

Long, I think it's too social tenancy law not fully explain here. I have now also used in this lecture that I talk about some says: don't go over quickly if you want to know more, in any case, the chapters, a few examples to repeat again directly here, you can first of all. Okay, that explains marina silva, has several expressions and we're expanding them here too complicated.

A

That's always a thing with markus it looks so much stranger characters at first thinks that everything looks incomprehensible, alex wrabetz looks even if you 've seen it of course also magic, but once you have understood us, you can see through it more. He number one here switch again drive, so our repeat pair that we have many forest and the expanding just always the m + behind it, and because we.

C

A

Down a monastery I still have zero in the end with it, the search does n't change, because that's.

C

Another example of a light that.

A

Makes sense you wouldn't use it as a gift, but you could use it for a special case, and here it's maybe a bit confusing. We write here: 12, rainald, love and 3 times.

C

A

Is also an expert, our journey, his expressions, two semesters already by looking at 1 and when all.

C

A

Is used then, first three times 7.

A

It is a district town 13 behind.

B

A

A

24, that makes more sense. Yes, I do.

B

A

Know 13 stood I hear that in.

C

A

To that, it is also noticeable that we have no boundaries between expressions,, which is okay,, but this expression is evaluated as 3 times 7,. First then, a second example is you can take a quick look for yourself before I. Explain it, or one of you explains it.

A

No one wants to understand it.

D

A

D

Explain it just.

A

Makes sense sometimes you need it. Maybe if you create a lot of constants, you don't want to keep repeating constant 64 well. Well, it doesn't make that much sense that marco, but you at least you can see that you can have two different meter variables on this repetition and, of course, several have here in this repetition a meta variable in it.

A

Then we have a constant character, which token is a meta variable again, and then we have a constant token again, namely semicolons in them always have to be repeated, and we do that here when we leave- and here is an example where you could use brackets more cleverly and not like that, I think that will be reasonably clear if you look at it again at home, calls and now something more complicated example like to come, of course also. The default example of prevent.

A

We have it better here. If it.

A

Somehow separated by a comma, I.e. tff, or also longer word, that in oslo, that means it’s still the culprit. First of all, no that’s the sign very small, specify program planner. Then we really like to have parameters again, at least one, because I say that they are separated by commas. Then we have the tip clear that such a construct, ear is called for us and I also linked clay ground.

A

Here are all the examples, so the whole concentration of point and fibonacci is still there. That was our first definition like that. Just then passed the name of the type and the constructor to the lines that are used and then start by adding this second rule that we just added. We still have these generic parameters can hand over.

A

And we can also do that with this genetic point,, whereby I killed a bit this origin for the nation or exactly here the origen I didn't implement that correctly. I would then, of course, actually have to write a zero construction and on t yourself implement, but that's over the goal. Now you can take a look again. Maybe I'll just keep going, there's one more.

B

A

You can open up about the smart I can also, for example,, not only give ten markus in seven big recently, not the fusion of let nato be called up again by itself,. That means it keeps expanding, of course, I hope that I somehow have a request for revision. Inside,. A small example of what you could do is that were at some point. Marco hopp would like to think up something from a government. Syntax xml makes xml lawyer.

A

The pointing thing can be something like html or html is more or less partially attached to the set of xml looks something like this pointed brackets. That always close with syringe came to light that we like to write bin. Is this here? We just think of a syntax.

A

We don't always want to have our day repeat at the end, but simply these are almost more similar are almost always a snake and now think about what, whenever we write something fixed in there, because what we write in the string we carry all by ourselves in double points.

A

It's also a little bit easier for us that we take a break so that he can simply hold the syntax, and we wish we would definitely consider whether we can implement it and, of course, that's quite constructive. Of course, that means like nesting windows, as you like in our call. That means we can also- or we would have to use your revision with a signature. Xml therefore has the two simple cases as a man who was completely empty for casey such as not at all, not really, but you could need him.

A

That is, the rule will be completely different. Less brain divides universe simply because we have a colon and then some expression. Then the attitude to this expert is implemented and now comes the bad part of it. Actually, we only have everyday life so html, for example. This is an event just a word like we bracket here close again, underneath it now any number of dts that stands for token closes. That's the generic thing you can have that doesn't really require anything from the syntax that just says that something is in it, and that means these.

A

Several files, really close anything can arise that orderly and then we still have topping closes then, for example, here this team, this head has a token tree in it and then of course another one. So it can continue and we.

B

A

More there too, and we always want to give it back as training that doesn’t.

B

A

That previously in we have the first day in israel, with top klamandt, opens up here again to zero means. The title has that we might upgrade to the new parameter this format, the content and then comes the other parameters of the first. Just this day use this great marco in string giffey, some porsche are extreme converted into the corresponding string. That is a shortcoming from the city library. That means this tag in this idea and it will always start converted. Then we call inclusive, that's the funny thing about it.

A

Now is xml on the inner token and then open again on the internet war, but a bit of it.

C

Is actually until.

A

It ran after developers is always easier. Is not that easy, like normal things you have, but it fell on your life, and that is quite nice. There too, there is also a.

B

A

B

A

Shown limit macros and dvd system nice how these work and we know how to.

B

Integrate modules markus is interested in not getting rid of.

A

Everything very early web compete expands before even so-called name resolution is executed and compiler. That means the names are looked up in normal in the modular system, with normal driving, the markus are already exported. That has some advantages that has happened so much, because we can do a few more things there. It also has some disadvantages,, for example, that the markus don't have a real path and they aren't public or private, either So, that's completely different than what we've known before and that's why we now have extra rules from Markus,, for example,.

B

A

Has marco in a module 1 here that we have to use like a bit of the module, say, market news or if we also imagined an external great, we want that this external trader crew use the weather was strange, write about it the other way around.

A

If we prescribe an lag, what we want to call from another create, then we have to say the export on the macro itself, so there are somehow just two stupid annoying special rules, but who cares, and what else The important thing is that what confused me at the beginning is that Markus, as well as stupid, c functions, have to be defined in front of the user,. That means before in the field,.

A

That means, if we somehow wanted to use Marco first and defined it underneath it doesn't work, I, don't know how some had already programmed or c++. It does n't matter what was previously defined.

A

D

Is exactly these tests.

A

In the documentation are carried out, especially by fire, so it doesn't matter whether we understand the ones before. But if you write normal unit tests it will then yes do. They have to stand off, which is a bit annoying. Sometimes if you want to enter all your modules in alphabetical order, for example,, you normally ca.

A

N’T always do that because you have to mark the modules are defined by markus,. He will climb to the top. So.

D

D

D

D

A

D

A

Exactly right, so you will see in spd. There is only markus burn directly into the cd and spd is currently included like views. That means markus could use everything like that. The office down so other paths. That is also.

D

A

That of the us community is very aware, and they are already considering replacing some kind of marco system somehow halfway well, so that rom is experimenting. It has many advantages,, especially comparing it with ten, but many disadvantages have also been noticed. Here is a bit and make it nice.

A

Well, maybe it will at some point something new will come, but now we have to be satisfied. That can be quite a lot and 9 times very briefly pointed out that I only wanted to say a little like that you can also more or less the batteries. If you want to,, for example, you can Tyler really handed it over and combined it like this. Then the compiler spat out what happened after the marco expansion step is available in the source code,.

A

That means I can do that too,, it's just too exciting, because you always know exactly what comes.

B

A

A

B

A

It here in the market.

B

A

Then we enter some expression. What do we do with it? Then do it experts it makes far too much sense, but we want to see something else when we then call it up in maine with +42, but then I have to say that I want to use knightley now it can be stable, so that comes out.

A

Let us also be very interesting that in particular, all these spd things are already being used, so just concentrate on the bottom. For a moment, it 's just being used through two plus four and this source code. That's what it's for now, compiler, more or less continues to work. You could put this source code into a compiler, so to speak,. Almost the same result always comes out because the side step that happens before everything else.

A

Is used and the definition of markus is no longer used as soon as this step once it's over. You don't need the market definition any more, and that's your great thing that external create spd is integrated here. I've already promised another ssd I, don't know why and markus also likes this external craig that you like it too, can use from it, and this flower prelude is also used from sed. You already told me such nonsense is inserted, but yes, you can definitely take a look at it and.

A

Exactly team race, markus and lures are that means helper, markus esser standard library which, unfortunately, are still unstable, but you can use them to help yourself a bit.

A

And although I can also briefly find the pointer on this html part, I think I need the nation to bake that a bit.

A

Because of what we use, the nike compiler for that's right here in the front, that you have to insert and that you have to feel and insert something, is now being output on the terminal when compiling,, namely how these markus are always called like this,, and only.

B

A

Xml is called with all the stuff, and then the tu xml is called again with an empty other tricks. Ml is called somehow only part of it like this would have there. You can easily or more or less easily through the jaws.

A

A few important brands and spd we already know some there I want now a complete go into a few opponents would like to briefly mention, because people are always confused and amazed at what is possible. There is including blood str. The cube bikes include just does that from another from another file in the world text copied directly at this point will use.

B

A

B

A

Text shouldn't actually be used are funny, but in the dr test you can load a file too complicated time in and either as a drinking animal or as another. That means, if you somehow have a dictionary with quite many West German words that you search nights or a name directory you can include the internet include sdr. If you have the chance to do the file concretely, then it is as if you had written this file in quotation marks directly in the source text.

A

It sometimes made a lot of sense and there is still illness and string ran a backup chance, see otherwise helper things and especially to define yourself market and again here the link to the complete chapter outlines book. If you want to know more, then definitely take a look there. Everything is clear so far, then I would not only talk very briefly about compiler planning that everything is possible and but falla plugins as.

B

A

Said there is this winter external or the disinterest that is even more complicated, exciting intersex, long-distance shot and I want this extremely because we can than execute any codes too complicated since the access to the source code from which we combine. That means we really have so with are, for example, we only had limited options for dealing with, it would have to say clearly pattern matching where we can use that and replace it with that.

A

But here we can just use any run the code who will see right away that it is also sometimes done so far. It is all unstable that needed the compiler. That's why it won't that's why we won't really use it yet. As said in games coming now, rex probably know most of you. That's what you do also, I think in informatics b. Of course, you also have a rex.

A

Creator is not one of the standard libraries, but there is a source, for it is managed by the official rast developers, and this is extremely good and there is an interesting match. Race. Exclamation mark marco doesn't know how you are very familiar with dragon,, but a rex was easy, or if you use right,, it is usually in two steps,.

A

You specify these radics in some form in this strange syntax, and then there is this algorithm that somehow takes this syntax and then the string, the people want, for example,, an html page or something else and processes these two with it,, but that now runs fast,. The almost one recs engines do not take this.

C

Strictly and run.

A

The algorithm,, but this this definition of rex is fitted and given a different representation brought, for example, in a finite automaton of the declining format, idea that all automaton differences are exactly in some other, better representation that can be brought, and you can put a lot of work into it to do it really quickly that you really do.

C

A lot of analysis on these streams.

A

This radisson, that you really do that as quickly as possible and that you design these machines in such a way that you can jump very quickly, extremely complicated the topic. In any case, we want to combine our radics beforehand, a better form that, as the theory behind.

B

A

And normally this will be trailers combining is always done at runtime,. Of course, something that is not actually done at runtime,, which is why these directors are usually already firmly in their heads,, which means we can compile these registers at combined time and that exactly this macro is still important here. Sometimes the better rating scale, external external trade is that some krejci you could also write. Maybe and then you can now talk about the too complicated time of the fight to carry out any work. That's just an addition. I find it very interesting.

A

Unfortunately, it doesn't work well at the moment and the normal variant of the director runtime profile is much faster later, but it's good that it's a bit more complicated I won't go any further and I just wanted.

C

To briefly mention.

A

That the astra ixengine is extremely good, so it plays at the top with walter rabbers engines in this world, especially that of a complete unicode support, just like that, and it still so fast where, with most other redding james, you have to do that extra with unicode and then most of them still master them slowly with unicode support. So we are really on board with that one of the best angeles, that's quite nice, there's already interest is other languages , so other languages can use the rast radics engine with the confession: neighbor example for others.

A

There's the creative or, however pronounced how about it's about the realization and write about something like that, and if you want to have any point or any character and since in the raiffeisen leasing realized. That is the casting.

A

That means this series is now building some additional methods on these types, for example, methods to realize a lot and realize a lot and then.

D

B

A

Something like that say, I don't know how jason knows it's such a standard format somehow quite often a javascript connection, but it's also used like everywhere and since now, this friend is simply handed over and jason gets a jason from it. That looks like it's great that doesn't work like jason is supposed to for almost all formats. That's probably a wrong statement for a lot of formats. What can we realize again that jonah jameson string and want to get a point out of it and we'll manage it that way?

A

So it's very simple possible with these three for any structure, students write or something else that the realize to the very realize to jason, but also at the same time, in binary formats or a database. That is very interesting. There is also only quite unknown craig. Then there is diesel. That is an orf and query builder stands for object, relational mapping from the mandate.

B

A

Of databases has ok, so these orn are very interesting because we don't want to write these sks leightons or commands directly on the project. But we can just write the normal code. We would write and from it the esquire is created. What is this query builder? And here you can also use the mature example, birds and initiatives, and then you can do various things with this friend,, for example, simply query or insert from a database and the following marco marco macor is.

D

Also interesting that you can.

A

Do that continue to write like this and give a URL to a database, for example,, so don't be a postal address database or whatever? That does is that the compiler or the compiler flickers is too complicated is part of the program with this database, because the whole connects Information from the tables is selected and the code generated from this information is displayed in this way.

A

This means you no longer have to specify your database definition twice in plain text,, the cities of a database,, but you can simply say get this whole table of information from this database combined time mind you, we compressed the program exactly this usa, extremely good, that's actually never worse than self-, written, sql, currys and often even faster. That's also quite nice. There.

A

's an example I'll get to the.

B

A

Soon but they're such great examples there's never a laugh. Everything is possible. There is also a very large sql validator there. You can simply decide sgl calls out and normally no longer have to write to our sgl string. If we.

B

A

This, in any case, we can write in there and are now automatically sometimes combined, but not mainly checked again. That means we made a commitment here. That means the compiler the rust compiler will print out into the glacis, so we can simply write a syntax extension ourselves. Now, all of a sudden sp understands that the compiler can send money,, even if it is,, then there is also the computer graphics among you this here, this marco glas people.

A

That is not somehow something that looks similar to last or is very similar and change that hungary shader coach. That is not exactly rast but looks similar, and for those who have already written shaders that you know here, a few things are handed over to werner again or caught up and various things are done. I also find that very interesting. You can also imagine that the shader is fabulated at the same time,, for example, with this modern format. Bav, that's really nice right now, so you can do that.

A

Take part in a lot of things and finally, one more thing that came about shortly before christmas, which made me very happy, because there is finally a really good work framework for rast raus that you can.

A

Make rocket fun out of it. So far, that's just a function for this, the dealer web dealer function for all http requests that go from the http method and are to be accessed on the following journey,, in which there are two parameters in this phase.

A

Called this age in the url does not fit is as 8, then just a lot is returned to us and it ended up on the webpage. That is extremely short. What you can do allison web framework. I don't want to go into everything, but it's definitely amazing what you can do. Member all these attributes about the functions indicate various things. How was because dealers that does, of course, only for those who have heard of web development or something like that or are at least a little familiar with web frameworks as an official impression 2.

A

As said it is only before at christmas, you get a lot of such features. There are here and there is a small ray of hope, because everything I just said is stable, but there is markus 1.1 which will be stabilized soon. These are only customs but customize and already for a lot of people. Things that make sense, for example, wer will work completely thanks,, and some of these will also be stabilized.

A

Somehow. The next versions of the World Cup will.

C

Be out for five weeks.

A

So I'll be there in the end,. There are still questions.

A

Well, then, have fun with the tasks.