Rust Programming Language Programmieren in Rust (Full lecture, German), 30 Nov 2016

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From YouTube: Programmieren in Rust (30.11.): Generics und Traits

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=2c961a8f-e86e-4335-9a6f-90e8a6d435f5

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

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

A

So you may have noticed a good quality to very clear quality again with maybe no, but this time new and keen on the gaddafi thinks that is probably already the.

B

Case before we.

A

Becomes a little less chaotic than the last, at least of course, the feeling that a little chaotic, because I would like to more or less complete the rx and trades today in any case,. As far as you can speak of final, because we will be dealing with the grass all the time with these topics, magix am trades so centrally in the whole host system are integrated so again, a little hint. The advertising didn't bring that much. So my great term peter plate did n't get that many more downloads.

A

So you see it's somehow still within limits. So somehow not quite that much done unless you will soon be writing a huge application in rast and then using it, because he has already had such good experiences with it,.

A

So we will start with a small task,, namely quite a lot of information about trends and rx for the last time,, but now see how they implement some trades,, because you look at the shades clown and copy, and we've talked about clown püppi for a long time and always treat it as classes of types,. But we can imagine clown and copy types are, of course, also in one trade hidden, so so can abstract about them. So and now I would like to know from you: how will they write a trade that represents clown? I?

A

Think that again, what is complaining about so that 's, just a team that can be published explicitly just where I can write. Another new instance can create a new instance. This guy thinks about how you would formulate this straight. I hope that everyone will wake up from the last time.

A

So the first thing we need to do is sign this declaration, because now I mean suggestion.

A

C

A

C

A

We first have to give the name its.

C

Method, yes, okay,.

A

And then again.

C

No nanometers as a return worth it itself, capitalized.

A

Exactly the problem last semester, not at all, I try, maybe that the system can do me in peace, but of course it smells and tastes like __, ], jason wrote for so.

B

A

I wrote before that, because all methods are kind of papic. It doesn't make any sense with jade's private with us.

A

And what did it say that the five meters.

C

Takes stayed because they are doing as a reference.

A

D

C

Engelbert PERCENT.

A

And how to have driven you off the rock, what just your own type is given. I hope when you look at that, more or less around that a meaningful definition is the hourglass.

E

A

For this clone world.

A

B

Run into another, but.

A

We see that it.

B

Was also defined.

A

In the same way- and that is also the correct definition from the city library- we are still a bit of space. There is another method and the women there can then be copied. That means again what is in it. It will be for you that we are exactly right again, the economy you can already implement it only with the help of flo yourself think what you should do, it's about clear, I, also somehow get a source that should be cloned and then assigned to yourself.

A

I. Think you do It is clear that you can only implement it with the method.

E

A

Sometimes it makes sense to overwrite this default method,, for example, to improve performance. For example,. If you would like a string for this internet,, you would like that use the ball that is already in cell, of course,. You couldn't formulate that in.

C

E

C

A

If you want to improve string performance, a bit,, you can overwrite that,, ok, commission, koki, trade,, take a look and what do you think, like us,? It.

A

's been around for so long quite suspicious that but such a line cut, it looks like this and there are two things packed on kontron, which means that once the fuselage is completely empty, that means a.

E

So-Called smart trey, parker trades.

A

Star, I really quality ready, so you can't call methods on it, but you can only mark types that format straight in that means I can somehow I could even just build a trade. I like these types and then, of course, the tray for a couple of types that like them without them, then providing a functionality that altern markert. I think there have been marca interfaces for a year now that you get to know it. So it's not too far away. I think the.

B

A

Are maybe a bit confusing, as you can imagine, what that could mean is.

C

A

We're guessing this amount relation function, copy.

C

A

If you sign it like that, then it just means something like you. The copy must also present clown according to it one that's actually called trade-in hurricanes, but it doesn't have much to do with object-oriented inheritance, if we'll see in a moment can somehow define a field and then say sunday with a colon. This trade requires that the implementing types also implement these other black, so that just means that trade up doesn't really matter that says, only every type that implements me in this case for must also require a and b implement.

A

For the slides, look at this again as an example as if we define his trade extra and that.

E

A

I'm dependent on base, so all the guys who implement me still finance the basin and now we'll just cover it. We would only implement extra for the 32 tyler war said: okay, this trade bound is not satisfied. So in this case, yes, if you want to implement something for extra, the trader base has to be satisfied. I hope that makes sense. Somehow we always say it has to It is also useful to implement, and mainly for two things,.

A

If we want to combine several trades, for example,, we want to write a large library and we want to deal with types.

E

A

Often, the clown display- and it somehow made me implement three trades for types for trades there and deal with it. You can, of course, somehow always write with the double with the flow syntax for each trade bund, but I can also summarize such a trade by simply saying this trade requires that traders trader straight and then that is just a summary of several trades and I can practically give a trade a new name.

A

That's one thing that makes sense, and the other is if we already want to use dead or functionalities from these other trades in the default methods. What would this.

B

E

A

Have that would have a method somehow ne this time drove then I could implement a default method here in this extra trade. On the one hand, with a body that uses this tool, because we said we depend on base. That means every type is not implemented implemented on base. That means there is always an implementation of these our fumito.

A

These are the main reasons why you want to do that sometimes occurs a bit, and here we also see quite clearly cash in a create a subset relation by saying everyone who implements the copy implements that makes clown implement. In particular, the british puts here. No own functionality ready. That means the compiler does n't even really know how you should copy something, because not this small implementation and important again that 's not important who at the house of object-oriented programming, doesn't think you can unpack your java knowledge again and just beautiful coloring states built.

A

That's not how it was intended and does n't really work that way we 'll go through more examples. I think it's best. If we look at a few examples- and in particular traces are the most important thing you can talk about in the city library, because we're talking so about classes of types, we.

B

A

Look at specific types like we did with option, which is also very important, because when we talk about money we are talking about. A lot of types makes a lot more sense, especially crew.

A

You've seen that before I've seen you on a worksheet, it is recommended to access it in order to be able to compare something, and we should also think about how this dress is defined,. So this pair of chilli co that should be used for comparisons between types,, not comparisons because of big, smaller ones,, but simply about the same or different topics. Idea. How.

B

We want to define.

A

A method again.

D

A

If we donate here, we always compare the content, it makes sense in the very least cases to settle the storage locations and last says we actually always want to compare the bright men who write the stores. First, compare weinand. We do that extra explicitly on the right. First of all, we have this. This.

E

A

The free parameter one and the other also against operated by, and that will return. That means I want and that returned whether these two types are the same to free up a bit of space. There is something else, again, a default method we have here. This is the game of articles and that gets the same parameters as well as a boule, and yes, it stinks. The friend imported always has an idea for what it could make sense to overwrite.

A

E

C

You maybe very, can simply show inequality.

C

But negation is easy to check.

A

That's okay. I have my something maybe, as an example is maybe easy to present a long array, e.g. vector. If you want to compare two vectors, then you would want to show equality so around here to show pages. It's probably actually she's. Yes, I think it's what I thought recently. So the idea was to show the.

C

A

Ones here you have to integrate all the way through and say show that each element, maybe so equality, is more difficult to showed the inequality, but where I didn't do after here, of course, also just very quickly. If return, if you've already found the first forest a bit unfair, ignore.

E

That just that.

A

Was maybe a bad example, but maybe it'll do it at.

E

Some point they're.

A

The torture method to one exactly and now the question arises about this trade is that we really only want to have that we want to have that in the city library. Does this straight, maybe restrict any decision against design decision for you, because the 1 could be too restrictive. The state.

F

A

F

A

Is that you could somehow, because you want to compare between classes belonging to certain classes or species, then that wouldn't make sense, but I didn't think so straight I have another example: it was if I was kind of exactly.

A

Right and I hope you do n't like that. We want it to work somehow,. That means we are too restricted here,. We said we can only compare the same types with each other and that's why we're doing this trade,, so we're modeling this meeting a bit around that, too,, not the original potter standard libraries. Now, how can it be made more general? And that makes me like this. We.

E

A

See a type, a trace here, no type parameter. That is not a problem. We call this type parameter: hsv, rheydt, fansite, but often somehow a second operation and.

B

A

We see that this argument is always of the right side type as we do n't take eleven, but sometime other types. What would you appreciate what this means here? This easy help, those in.

B

A

B

A

Exactly the freud parameters- and that means we can also do this test. Rachael iq like this, without to explicitly.

B

A

Type of parameter train, and then we mean that we mean that we calculate parameters for the people. There are two examples, and these parameters also function for other things where we can use them, and here we.

E

See the two examples.

A

We can just say island parship for string you, his courage, league, without type parameters. That means that the friend took this first line is the same as if we would say in the elevator stream for string and the second line now just says: marshall iq strings, read for string and that's how we have.

B

A

Types of comparisons, I hope that there will be some minor snag. That is still not exactly the chorus of the city library that will follow soon go a bit further. We have now confirmed met question: why does it have a funny name- and maybe you already have a pair of shoes- lord or then seen the trades, itu and porsche, and we wonder where the finished product and cake just seen. That is good for a partial equivalence relation. That means this equivalence relation has to be symmetrical and transit eve. Let's see if I've noticed correctly.

B

E

A

Is easy if the people maybe b is then it follows that also the same as and should be so attractive that is actually completely off, at least not all. That means comparing is and the same.

A

Is now perhaps.

B

Not surprising, but that is only.

A

The partial equivalence relation and you can.

B

A

Further and ask for more: that's because that's the full riverland, so a coherence relation, not the partial. That means additional reflection, and that means, as far as I know, it's just always the same so that it's always school studies. I.

B

Like to improve when.

A

The lamp stays with it between better.

B

I know that's actually.

A

I now imagine that.

B

Since any option come back, come 20 accompanies.

A

Actually, the only difference is welcome on the.

E

One hand the.

A

Definition of iq- and it looks.

B

Like this, and we.

A

See how that's my make up truck that does n't have any individual methods of its own, because we.

B

Just say: okay, these.

A

Conditions here this flexibility that fulfills that's just a broker. Traders in the compiler doesn't check whether we really have that in the implementation of our method units and it.

B

Is inherited and that.

A

Is assuming that branch q-cells is implemented? That means.

A

Providing this flexibility power in total, when I compare the type with itself, I have experienced that. That is why we no longer have this type parameter. It makes sense as soon as you look at your support, namely barschel place that speaks First of all about similar types of bags and they are anti-Semitic and Transit Eve That does n't appeal to me. There are very.

B

A

In the city, library, who can explain it again well that it's defined like that here too.

E

A

Again here, but they have a team parameter here, which also too rarely the consequence. We can create a reaction with any other types where he is equal to a large small and we assume the pastorate, the cow that quite interesting. So that also depends on that means. We cannot implement bar sport if the wrong iq is implemented, because we can imagine when we say to two objects- are either bigger.

B

A

Smaller or equal, the obvious that we can also say that they are equal, and here is the interesting thing that while we are comparing two things, an option comes back. That means sometimes can we don't say whether something is bigger or smaller than the other,. That's very interesting, that 's just a special case, that he's going back to that option,. That means we can't always say and think exactly at this place, guys who have a so-called linear order, the total order.

A

That means they are additionally as this total this linear order, and that is defined like that. So the same here.

B

A

Requires eq and fahrsport self and that reid anderson’s ordering china is not just an option of folders and I think I’ve seen it before.

A

Or is just these three and we may ask ourselves: what is it important for now? Well, we need this difference and in fact- and now we are getting a bit through, the grid is very precise and things are not just sunday carpet sweeps only so that easier goes from. Although there are these types and fills that is, and only a few ski league and driving sport implemented and not better deny better pure. Does anyone know why.

E

C

Could not really shoot the our thing about calculation is not really the same, because.

A

C

Here not to the extent so maybe deterministic by the way would like to have right there. So.

A

That definitely a big problem, but that wouldn't actually mean that we can't implement this chance. There will be another small, another small detail and there are special bikes or not numbers, but here arises in various operations, let's think about which ones. I think, if you finally get out through 0 tip, if you please 0 through 0, come in cash and had these weird objects, but that now has a weird flirt government and that's unlike all of everyone else, and that 's, and especially unlike with yourself, so you should just compare david lama. Then that's written.

B

A

The afloat specification the people should give back, so we did n't give them the flexibility eco didn't implement and in particular you can't compare it with any other flow numbers in a big, smaller relationship. That means lotte numbers neither larger nor smaller, nor equal to any other flörsheim.

A

That has the funny or sad consequence that we can't just sort race and floss with the sword method, for example,, that's always true, of course,. A bit also rejections, sometimes brisk race looks, can sort then directly. I can try it's really because it's not clear now where they are supposed to fall a little bit at the very beginning of the array or at the very back. It's not specified by the board and most languages just do something take just be careful, they don't occur and the user wants to be able to deal with them.

A

Yes, and here it is that you want to specify a little more precisely. If you want follow your crap, you have to specify directly. I want to put the northern countries first or last have so far clear.

E

A

Weird side, it comes out like that, a bit out how exactly that 's similar to unicode at unique, also gave me some complicated methods and functions. Just because the world isn't simple and like most languages, , that its in court, which just.

B

A

Further trades, he already got a bit more information today, and we would now like to define a stroke for the addition, and we have a rider time again. So we would like to add another one with us, but that doesn't necessarily have to Being the same guy. Can someone think of an example where you communicate simple cooperation with plus x want to do with two.

B

A

A

Sure they've all been done here before.

A

E

A

Good example, you could of course, also use it. I had thought.

E

A

Else what else more practical than I'll say? It's not limited to rust or system programming.

F

A

Example, it's also exactly that, although it's not really clear what the result should be, most people do it differently. I think I think that.

B

Many kilometers, you gave them the points and you.

B

Can use the difference two points for.

A

Example, but let's say something easy to give something: you have a matrix online lexicon that multiply or you can scale a lektor with a scalzo, a vector and a normal closes from mozart, or something else that makes it obvious are because, with the addition, things are not so good now, a statement, for example, that if you pay close attention to the fact that pump, lectors and changes of direction, there was that you can first remove it, according to mathys multiplication,. You can imagine that.

B

With this method, as brad.

A

Self insecurity and a weird output we've seen this.

B

A

Have n't really talked about it, yet this line up here the naturally associated type. This is a type that can be specified by the implementing type, I.e. any type. We want to implement this etrade on determine for yourself what this outfit is, for example,. If we were to tell you for the 32, the internet, that the output is also your 32 again,, my implementation would have an effect,, namely if we have our friend, not the generic point, simply the friend with 64 fields.

A

Yes, and then I will be friends in bed and here again, nothing else means we want two friends that is not explicitly.

E

A

On both sides, that means the friends of 11. They say we, the author of our addition, is again a friend tell me, but the.

E

A

Is different, so in particular, if we have two different different types, we want to multiply a matrix with the sector or something else. Then we have to specify what the type will it come out, soon,, namely multiplication or addition, and that can just implementing type or in the inter block that it specified I hope that it will then also be clear as far as we'll see each other later during example, if I briefly talk about operator overload who's ever heard of this term, oz t + + or where else does it.

F

Have anything to.

A

Do with the ones that I've now counted again will be alright.

F

A

Could get there so.

D

Operator overloading a little for ten.

A

Years, for example, doesn't exist, that's just means is we have these operators of the language like plus and minus, and we want to guess those for our own types,, so that means we want those with our own type can use such as with vectors matrices, as I said, and yes, what is not possible in c++. Is it possible? That means you can really somehow add two points with the normal plus health in java you always have to write methods and then call them.

A

If you discovered me saying vector multipla there to my years and stated on the matrix, how else what else come here that really make trust with the normal.

D

Rest, you do it.

A

By implementing these trades from sed victims survived, so if you just like that in ras write it out and we can.

E

Look at it as if it is.

A

Even for this here, just this trade is called in this case with this explicit syntax and the université wrong call center, and we can interpret it as syntax, and here we see an example again. So if you really just have the simple migration from a friend- and we would like to add two points, then that would be something to do here- a few corresponding instances.

A

That means the computer is one point out that works in the rast district plus programmers might not really be surprised,, but the java programmers who haven't done anything else, because maybe it's a very good idea that you can definitely do that. First in the broadcasting center, this spd on the module of the sun quite long documentation announces that read through again and that's really for everyone at least technical equipment. For most of them, there is something defined inside a well-known exception is the audience and so on.

A

What we just had, that is the appropriate trade for the bigger, smaller, maybe right up to speed. They don't live in this spd now, if they modules, but how you will then also find questions.

A

A

A

A

Again, unfortunately, you can't define nine authors,, at least not really we'll come to a very interesting topic later, that you can learn from paula, plugins and macros, but I won't tell you so much about that. Now you can find the next trade or jd power in this case, although if the in tour de france has you now wondering why I pray all this, it actually makes sense. You use these trades. Often you will see them again and again. So all trades are right now so imagine in to inform.

A

They are as follows: explain once franck trade that also with a generic parameter method return. That means we want to define types that are easily convertible from another type and intuition bit. The brother of that also has a generic type linda. What help return this genetic back? It means we are talking about this conversion and in particular it was more clearly lossless and error-free conversion. That means it should be clear when I call up what happens, then it should n’t.

A

Somehow we shouldn’t necessarily have to open the dogs to see what actually happens a type comes out or what happens, and it should be lossless. That means we don't want to implement it somehow if we lose precision,, for example, by 64 to 8. That's not implemented this conversion because it continues to lose data and error-free. In particular. That means there shouldn't be any errors occur. Something like pass is no other than an example.

A

Per error can occur or something like ku64 does that there can also errors occur, namely overflow, and we here are a few examples. For example, this left bar comments, this conversion of left.

E

A

Are implemented We've seen that a few times. I've often said that if yours works and if it's clear, which type is required,, you can also call town tue string dot into, and that's exactly this either on the right-hand side. If you implement these trades yourself want, you need to collect, implement a real chance. What should you prefer- and that is with a little trick, want that means impel sa many guys will look at it, a few special grandchildren that you easily overlook the documentation, but that are important to understand that. But there is.

B

A

If someone explain is it does.

C

The lincoln broaden I.

A

Don't know the right thing: mainz wasn't the very important point formulated briefly so with the otherwise idea would like to be.

C

A

Precise, that means we simply say every type is convertible into itself, which of course makes sense and in itself does not make much sense to call up the manual,. But if you want to talk genetically about many types, then it makes perfect sense. If we now say, for example,, we want to implement some type. We want to accept the type in our function. That is somehow a string convertible. Then you would also like to pass this function as a string, because strings are obviously strings, more collective, so.

E

A

Okay, now it's a bit more complicated here and now and let's try to explain that this does.

C

Something can be pushed into another type. Should you also turn it off can pull out another ship exactly that.

A

C

A

Implement some type for types of then is also implemented thematically in the other direction, of course, also makes you see.

B

That they are very.

A

Related trades, that is why you.

B

Should implement.

A

Them from there already after a library of these implementation, that means they are global that can then fall such very interesting and big general impulse. You should always have a look. There are also talks about further training. That means that is just commented. That means felt can imagine we can.

A

So it is a conductor, new brand trader's own functionality, and the special feature of this is only that he compiler knows about it and does certain things, and you can perhaps imagine how often children have talked about 1 means types,, especially östringen have gone through, and these that means types are just The one that doesn't mean. That means the type has a fixed, known size at the combined time, and that is also implemented automatically as one of the few trails for types in particular,.

A

That means all your types that are defined in this way implement them automatically. Without you doing anything, yourself is, and even without you that the tires is what the fear of recognizing types means. Someone remembers.

A

Exactly only str and we met another, someone else remembers that was a bit of a generalization of sdr.

A

It just was n't frings power, some slice, so somehow the weather written in such a way that there is some slice of biscuit.

E

A

Got to know that there is another important class of fear is called type and the mobile phone so-called shared objects. They won't look at us now, but they won't we'll, probably look at each other in two weeks and then in two weeks you have to do a kind of cocoon lecture and it's easier. It's about memory layout and the types in memory and so on, and we'll also talk about trade objects, and the important thing is now here that you always have a type parameter somewhere that is automatically formed.

A

You may remember at the very beginning, when we started, I said we don't usually know anything about type parameters. The only thing we know is that it means are, we can very seldom something with fear is called starting types, so it makes sense that all types are automatically called and there is a special are there to do this exercise? This band pick up because good things we hope for just sometimes when we have dance means types want to do math or work, and then we write question marks. It says as jd power for.

E

A

You look a bit strange, but that just means I accept here not only that means types, but also as types from strings. For example, and now we will.

E

A

How pacheco actually implemented in the city library, is that.

B

Is the old one we just had.

A

And that is perhaps the question: if you comment on what I just showed, does it work at all? We will maybe now I've quickly realized it won't work.

E

A

This the parameters further time it is built implicitly, it means that means it must always be. That means we say yes,.

E

A

Want that we implement it dr, why can we implement that for sdr at all? I actually said we ca n't do much with types as types I can figure out the stack port anything else.

A

Because you take a reference to freedom of travel here,, that means if the parameters hide.

B

A

Anyway, or less.

E

A

Can sometimes be afraid, means accept types and that’s.

B

Why this implementation down.

A

Here does n’t exist with this definition of trade. Invest at all of course, define it a bit more generally and that's why a standard library is marked in such a way that a pilgrimage point build, but this build that was actually a negative of the 1 implicit were okay, for just being can still mean everything can be, it doesn't have to be.

A

You think it's very likely don't write yourself or very seldom have to write yourself, but you see that often in the city library, because the standard library naturally wants to formulate everything in a very general way. That means do n't.

A

Let that confuse you that just means that it also works with different types of people that sometimes makes a lot Exactly, I just said many topics, a little, another topic,, although there are so-called extensions already in advance, that 's, not a language, again, Ireland,, now nothing new that he doesn't know yet, that 's just how trades are called that are used in a certain situation,.

A

So far, we have always to abstract a setting over several types, and, so to speak, a group of types, and they have a certain functionality that we would like to exploit now, but would like to expand existing types and trades. We saw last time we cannot simply write in petit 32 that is forbidden. Everyone could just add methods to any type without dad we can only say impel trieb if this type is defined in our current crate.

A

We would like to add such methods to types sometimes, and we can use it to help ourselves a bit rum heart model. These trades always have an extra example at the end of the name and the 5000, and not only like this rating base fixed.

A

There is also the fit of a method and thing 11 and how that helps. I have that was shown first, but that makes it there is absolutely no point in thinking about it. First,. We actually have to first think about what we actually want to do with it.. This is not intended to abstract over many types.. Now that doesn't make much sense, for which types it should now be implemented. We want to implement it to add functions or methods to existing types. Come so far,.

E

A

32 and returns.

E

A

A hundredfold on itself, and then you can imagine that we can write nicely in the source code. Credit three points: the 3.

A

With primitive types have to do, we can simply that the fiction, as I said, we already knew that we designed this trade. We already had it in our heads. We want to present it now for, inter so that you can write so we'll start with introducing others to us. Want you to write on that makes sense, or not, probably first, it doesn't make sense and then think about. How can you define this break and implement it for a guy has a completely different purpose of this trade but and is sometimes used.

A

So we already have a lot. Trades passage. I will briefly acquire a few other ones,, so all of the ones we have discussed so far are basically important trades that you often use, because only then will there be a friend who carries what I briefly mentioned at the very beginning. Here again the implementation, fair trade. We have some people return with fleece 11 or that this means has to say here.

A

That is now a bit more difficult about how to then in two weeks there are a lot of top three important trades in the spd that there are wide on the ried and victory with the first two. The important ones are the agreements about things where we can write in or read out,, for example, files, but also tcp sockets, so sending something over the network. But we can also implement this for vector or string rector vector.

A

Children also simply know a write, the knowledge very general trades that have to do with how you write something in somewhere moratti. I would like to show something briefly. Then it is not so unimportant to have documentation and that we also know about it in a community.

A

It is sometimes very difficult to find out which methods call so can if we take a look at style now, for example,, so we're just looking for would like to open a file with just and are now somehow looking for a case like an arrow guy and see how we can do it, as well as regional examples, because we're at bars and who just tangle appears open a file, and you can already imagine it a bit.

A

So we take some pe and this peso it aptly how to implement. That means you can somehow get it out bland, not that important. We can definitely because we also look at an example. Reichling strings are passed, no problem, because we definitely want this arrow to do things with it. If we just look at the methods right here above there is nothing useful about it, we can somehow don't write anything in it or anything else, and there are actually a lot of rast beginners and say you ca n't, do anything with it.

A

That's problematic in the documentation. The first one below can be this trade implementation, and especially this simple ried incident, and these methods are actually the important ones here, and so these trade and methods, ried and so on, are the important market of dealing with the file and getting data out of it 's just a bit hidden that I don't worry about that. So sometimes the roll down and the important functionality of a guy is actually down the trade implementation is hidden, so here is once ried and 1 x, ride for veil implemented and on victory.

A

Why jump here or something like that? Advise that in any case not let it be used. Sometimes there are still the trades cent and sync: will we possibly be too, but in two weeks at the.

B

A

We deal with the parallel programming, which is amazingly, simple and amazingly safe, so me now, then there is also the job trade that is to say briefly beforehand the the structure from plus, but we will also deal with that later deal and then there are the spd budget trades and they will now look at the last examples. What happened again about literature? I have often said that somehow there is literature in that there can be several things, but we can imagine the word. Trade is hidden so since we can also start with tracks, then somewhere.

A

First of all, this division is defined, and mainly only these two things below that there are many other. The volg methods that we no longer have to implement, but the red devils are just this one and this assistant type so.

B

A

Something that an element can deliver and sometimes can also say there is no element available. It is a.

E

Very general definition, so.

A

The literature can, of course, define which, which type it returns and then simply has the next method, which returns an optional type. It is very,.

B

Very general, this.

A

Definition, that means yes, okay, maybe just a little bit more about all the default methods. They are very, very useful. Most 100 futures can be used.

A

That means we will also get them later at the kiosks, probably in the next, but then it would be we're having a lot of fun with this trade,, but it's actually a good idea to use it sparingly.

A

Types speak, it definitely makes sense can do that, and there are two more extensions. If you add extensions from dieter reiter trade. Now even more can once give this exact quote. Who knows the length of himself and knows how many elements we deliver? A learning method will then be returned. Accordingly., Of course,, you don't know your data rate,, but some know something or many know. Something,, for example, when repairing a macd.

A

In front, and always that only the next element goes where, but also in the back that also works,, for example, with the vector because then somehow random access would be as far as everywhere in this area or inspector, but for links if it is not necessarily possible, for example,, depending on how it is implemented, but that we have an example and another example where a double ended, rescuer is not possible. Is this one day three points to express the ultimate? That is the half-open rain? Stefan three starts and then goes to infinity there.

A

Of course, you can do it badly. Somehow the next element from the back down- and that does n't know his thinker, by the way,, but that would also be a generator.

A

What do you think implements? The other ranger point point 3 implements the literature that this trade.

A

E

A

You, the one you very well in describe a suggestion. Then it just keeps going, but it can't do the decisive, throw van gaal we just can't implement. Then there are friends of these lex methods here and those were 3 traces to talk about literature directly. If we had something else trace and suggestions to understand, because another trade that one intuitively defines as follows, we also have.

E

This item here again that.

A

Gives separate zones, but then we also have an associated type. That is the intuitive. That is the type that is the actual literature and then have this method that returns. This crater in German means a guy is in a theater from the animals, for example. So that's the requirement for the loop I'll. Look it up right away and it's an example of vector if we take a look at vector implemented, not not himself the theater week, somehow a way of remembering where he is at the moment. The vector itself, of course, does n't.

A

Remember where he is. Why should we add another variable to our path? If we don't need it most of the time the vector So, it doesn't implement literature,, but the vector can be formatted in a theater and that's just another type, that stores the vector inside itself and then another position where it's right now.

A

Just still in this position, as you are right now, that's why this level, above it has intuit gate that makes it a bit easier and if we don't, but if we really write in front of blah blah blah in expression, these experts just have to imitate intuitively. That's the whole point of it, and here too there is a blenke temple that at the same time, exactly this, I will show right now about the.

B

Criminal record that.

A

Just requires more intuitively.

A

E

This generation here for.

A

Example just say directly for the vector and like to put this type t, and now it comes price question internet as well as for a reference to a vector implemented. What do you think is the type? So what does it say that in this first arrow is equal to width?

A

C

A

C

A

Had previously explained very practically that we assume this data structure in the researchers and if we everywhere establish vector directly, then the vector is removed and you can no longer use it afterwards,. So if we write a variable in the vector out loud,, then the rector can be used after a few minutes,, but you can also say in front of the blah, blah reference woke the variable,. So we go to a cheering refrain in this club that puts it just endures.

A

A meeting in youtube, soffin vector, also implemented intuitively, and there references to the return may have already been seen. The same is then also for the frames made in youtube and.

E

A

Blade has in that means only if I already indicator then implemented is also intuitive. If I can obviously refer to literature in a budget rate of animals that means, for.

B

Example, that here the.

A

Denied bike tour directly, but I can never prescribe that either because of the distraction. Kimpel.

A

B

A

Already asking.

A

C

A

Slide then, if then write a little something or I will look at it a little bit from a different perspective. While writing, you may remember the question at the very beginning: what option is that a type, so we can first have a few the 32 and option ii. 32 is also a type that 's pretty clear. The question now is what it is option without type parameters, and there is the answer he's heard that name before.

A

Actually in the first lecture that a type constructor when we have a simple type, writing it down, then you sometimes do it like this. You talk about the so-called germinates of a type, so not a type, but a type of the type. So somehow one meta level, higher a type is represented, quite normally by an asterisk, and a type construct is now often represented like this.

A

We have a type and it maps to a type or something like that means exactly that. We have a tip constructor, because it takes a type and then returns a type. We can't imagine whether jazz is a type construct. It takes a type such as the 32 and returns a type option 32, but just do it with the fitness program. What do you think I could overwrite it in black? What is that you are asking for an example, type fits one does.

A

N't know it yet are ex and so on.

A

B

Good that exactly is old.

A

And actually also two types and then one type is returned, so a tee and one and then comes back. A type is of course funny syntax here that lenya put everything in a row a bit.

A

Unusual, but writing it in the same way, one after the other is just one now representation. This is not really important if the guest should program, but just to broaden the horizon a bit.

C

A

We have these types of structures like one type next to others and new smaller other things, and these parameters are recorded. If I somehow get a generic about the topic, then I can only assume concrete types, and I can't give a type like that without type a meta data tell us about so- called heuer, no details but, as I said, that's not important for us first of all, but if you I'll hear that at some point that 's interesting to say that flow is known as template, template which you've heard of templates before.

A

Did a bit of theory for a moment, because it's always so much fun, at least for me, and then I'd be done with the slides and will pre-program a little thing, but then end it pretty quickly. There are already questions how to there are hardly likely Ask if we were done with the tasks, but it's just about doing a lot with Switzerland and at some point it comes down to how you actually have to operate these strange trades.

A

What we want to do briefly is to program it again that I can do for you, but if he wrote this with this review,.

A

It somehow read a string into the terminal and then a user returned, and if that wasn’t hughes, then an error message was issued and the user was asked to enter it again.

A

And we’re in the situation completely understand that, of course, it is also important that you take a look at things again. I have provided you that we understand the freshness, then at some point now who will just see how it works. First of.

D

A

D

A

Implement this ritual that, of course, a user gave me a little bit of that from talks not exactly about everything but talk about the important country right away and first of all, we have his hatch. So we can do it again and again so wait as long as the user inputs the meat and that As I said,, you won't type it down like I'm doing right now.

A

If you don't know exactly what you want to do, and we would like to use that module because then we have to do some things usd in that as well as trade on the terminal on this standard Enter, the terminal and this stm. What we just look at everything here is this function spd in the return 1 hour in object of any kind, and the sed in object can do various things, but also here in the methods. There is nothing but useful.

A

This we would use right away, but important is also all these things that are in the it implementation so also spd in implemented advised. But we now actually want to use the method and about it. You just give a youtube stream and now a styled one comes back. What says: We are not interested in the signs being read,, but we would like to take a look if something goes wrong. It only goes wrong if that is not somehow, which is very good if the spd in is not available or any ciscos go wrong with it.

A

So of course, maybe not the finest way that to do, but it's only possible if now a line is read in from the command line, exactly one line, and you want to adjust it now, of course you know schott roughly how it works. There is this parts method what say, e.g. ss cars, and here comes now back. We've already worked with that for a short time, and then people want to get closer to say what should happen, then, as an is okay and then value statements come up return.

A

Runner is then we'll just say.

A

A

So far so good.

A

A little thing I'll say now: instead of that, try, this red lion still reads the end of the line, so the bag, / n- that will always lead to pasing errors. Walter these parts method or functions then says more. I can't fit the station doesn't make any sense. That's why we cut it off in the middle function. Jim jim reid, just cuts off the whole white space on the right side. That's new line also draws myspace with a lot of luck. The look will work now thought oh well, I had to be too hasty.

A

Spd is just a function that the ssd the objects delivers in demonstrates the long say the kilns are already too.

B

E

A

Why it's enough that it actually works? Another jus, try says always and then beg for a long time.

A

Works, something has to be entered, an output might be even nicer, it doesn't matter what.

B

A

Enter then it comes exactly error of this pass method is issued, and now I can do that exactly the market. Also with user is, of course, no minus sign, because we now enter three, then it works so far so good. So we are somehow standing now how it works. The spurs have to look where it actually comes from, but everything else first a little bit clear one interesting thing, so this pass method actually say what the match is.

A

Yes, exactly that you collect a good example of what really collects the information from every corner. This pass. It will be here in this match blog rhein, and then there is this value retail in the ok arm, and that in turn, you can get in touch with this user. So that's really a bit tricky like the rest has. That makes then almost always does the right thing. What we would like like will this function be able to make this function a bit better output.

A

What is now of a shark want to read, how does this function end.

A

So I would like to write some generic function that implements this functionality from letting the user input until the user enters something meaningful, but generic about many types about what do we have to be generic here now, so we can first of all I'll start briefly. We can just say, read so then differently than in ried and how return nlt that, of course, now thought a bit optimistically. What will happen then? It can go wrong.

C

A

It's a bit difficult. If you have to fiddle around a bit, this whole part doesn't matter, it has nothing to do with it, but this pass now wants ingredients, but it's not necessarily clear that there is a function. The ingredients can make the string ca n't, what not for students if just write a type that, for example, is n't implemented.

A

Yet look now answer this fits does is actually defined.

A

Is ok, then I click on it. I don't know exactly, and those are leads. Oh well. Yes right here is the inscription, someone that is or actually the right. One got me totally like that and in this pass method, now also takes it by the way in the string module so implemented for the string. So the self is now a strings. Read the methane result of f&f this effekts, some type that implements from str, and that will then also be the magic trade that we need.

C

A

Have defined the word seen from sts like this, an associated type,, namely a couple of types because sometimes I want to give different fathers back. That's very interesting, so we you might want to have your own bug to match yours and news and have another one on to match anything else more complicated. We don't want to always return the same bug type, so this trade is generic about that bug type and the complementa tor can match that bug type.

A

Let 's see what the implemented is good for all the primitive things and for ip address, for example, that you can also blow.

E

A

String a couple of other things seems to make sense and now look here. Yes, this parts method uses with f colon. They are associated types of the generic types. You can still have a closer look at home. I'll go back to this here and I'll say our type is now also from the scr then import.

A

It should work here and so well. Well, clear. Various things is still wrong. You have to say that of course went with, and where do you actually specify the type? How can we do that? This method is as again highly generic can specify types.

C

A

The turbo for stone would say something like that say: parents, new skies.

A

I don't think it's quite clear yet what the community prefers, but I definitely prefer the second variant here, but you can think about it and should another error occur exactly what is it here exactly.

C

A

Which is defined in this by sdr trade does not necessarily have to go out was on the command line,. That's why we can have an error here where we want to output this error type with the normal meter in front of it, and now we can simply add another one and need it for this tree. We actually were klaus who say, and the interesting thing happens. You can not only build types that you have declared yourself here like tea, but also associated types. We can say web tv display.

A

That means we can access these associated types and say the host implement display, and if we need more klaus, then I would also like to write everything into the reactor,, I.e. also write the topic sdr in there. It can.

B

C

A

The question is actually completely irrelevant, at least that I know find out. That is easy. An error happens.

A

And it actually works.

B

A

And re-enter 33 works, so we quickly.

D

A

Our functions, generic and that was made usable for several types, give the example. Last questions.

A

Ok then, let's take a very quick look at the tasks to the I uploaded it yesterday and then you're dismissed, too, this time, a few more tasks, but rather smaller ones, so I hope at least the smaller ones we'll see in 2001.

A

You have to build a few help functions and you have to think about how I can do them as generally as possible, define if you have problems with that found by implementing them for a special type first, just to see that they work and then you can read from the body of the method or the function. What operations have to be done for me with these types? So what do I have to ask of the types and then could make them more general? And here you have to try the extension trade and implement something.

A

Then you two said you should implement a vector type, not with all the functions you want them to have, but with some and there too, we have to see how we do it as generally as possible,, so the vector should not only receive 64 but something first,, but for some of these methods and functions that we want to have later, we must of course, assume something about this. Generic type,, the vector inside, is a lector that contains a string as xy fields can't interact with each other. Where is this example?

A

Strings could theoretically be added by hanging the together, but common students say a vector of students. Now doesn't make any sense that we somehow add the and then.

C

A

E

A

Helper functions or that.

B

A

A help function where you should somehow build another rapper type that certain modification also behaves after a type that has been brought in. I hope, that's all doable. He does n't have to sign a lot of coaching. Of course, more difficult was good, but I hope that it can be done somehow. We still have questions about the tasks or similar.

A

Ok, then, have fun with the tasks.