.Net Foundation Design Reviews, 24 Sep 2019

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From YouTube: .NET Design Review: GitHub Quick Reviews

Description

00:00:00 - Approved: Add a Generic version of GetValues to Enum (probably GetName/GetNames) https://github.com/dotnet/corefx/issues/27453#issuecomment-534690642
00:24:12 - Approved: Add Path.RemoveRelativeSegments Api https://github.com/dotnet/corefx/issues/30701#issuecomment-534695882
00:37:23 - Approved: Add List(T) AsSpan to CollectionsMarshal https://github.com/dotnet/corefx/issues/31597#issuecomment-534703891

A

Well, if you wanna alright,.

B

So then, which one should we look at I? Think the first one we just said: we don't want to I guess the second and third equally applies yeah.

C

The second one you said needs to hit a design session and which, now that we've shipped three oh I, think we can actually put on the ballot somewhere. Yeah.

B

C

Then the third one is also part of the primitive work there's going to be a framework type for it somewhere and once that's done.

C

I think we're done, but that's probably going to be also its own session.

B

This one I guess it's fair, and this one is fair. This one is fairly. We probably ought of time.

A

So I gotta ask John for input on this.

D

They search of this other one. We look at this ago, yeah.

B

I did eventually have at some point the.

C

First one and then the third one we've looked at so far.

C

E

E

So what is the actual.

E

B

B

Honestly, like as far as I like to me, this is not about performance. It's just about feasibility. Yes, it just makes it nice at the time, but.

F

I don't be as fine.

B

I, don't know what the actual proposal is. Oh um well, I did still the down I think so.

F

Curious how there.

B

Was some it was some stuff in.

F

The discussion.

B

But I think I said I think I would still add on to this.

B

Which, I think is reasonable.

G

You know Kevin Duncan, Street, yep, I,.

B

Think actually might have been a dome with it.

C

Well, except you can't do lowercase, you know it has to be capital. You know, because the language is reserved lowercase for future usage and good enough. Oh well,.

A

But is the capital e enum using the constraint that was added to MSI L for framework, or is it actually a new constraint in MSI? Oh, it's.

C

Constrained to system enum, there is no like enum constraint in MSI out. The other is no.

A

Sure yeah, it's totally absolutely there- everyone has been like I, can rewrite this in ily. What the language, let me do know.

C

You can write in l, ni, l specifically constrained against system. You know just like we're telling it you can explicitly constrain and get the system delegate and it just works. Yeah.

B

L, you basically have a baseline constrain and then there's some specialized constrains like people construct. Okay,.

A

Because I knew that I knew that it was possible to do ni, l and the C Java compiler yeah it'd be like well. We wrote the error message because you guys didn't promise. You were gonna support it and then, like we shipped 10 years later, we changed the spawn almost like as long as you're on doesn't care, yeah I think.

B

The only concern Jung has which I shares like it seems quite random to just set it on one API, not the others. On.

D

One API being good values and not get names well,.

B

I think there was makes you look at this thing. There's.

A

A thing in the middle which is like you know there, there were like 20 methods where it would be a reasonable phone, yo and yawns like it would be unreasonable to do at all. One would be yeah. So if you.

D

In fact, the guy get it to all of them, I.

A

Mean the house.

D

Flag is the canonical example of one that I would want to see. Yeah.

C

But as flag is now optimized by the jet to not box, be in mind and be the and check that everyone's been making sure, yes.

D

Also tell the jet to.

C

Do it for the generica we.

D

Could so the reason I would like to see a generic one on has flag is because that way, if I do like my enum type, a dot has flagged some value from my enum type, be like they're both mean owns it fulfills the constraint, but it's mostly yeah.

A

So the guy he has it according this probe arts about the middle, so he did it for format, get name get names, get values is defined and all of the overloads to object, and then he most like have a. How about just forget that I.

C

Think this one in particular, unlike as flag, would be beneficial because it's likely harder for the JIT to rationalize boxing, where you're casting array types and things like that yeah. The code patterns that you could do that in are there's a lot.

D

I mean we could just start with kept values and see where it goes, and.

B

I have to be honest, though, like not ever check my list, and it seems worth to me to just not like I, can see this bit weird. Why we pick at Vedas not getting names, for example right, because if you do it for drop-down values, then well.

C

Get names in particular there's no boxing, because it's just a string, no.

B

But it's the same argument, but the usability is equally shitty on get names, busy, buddies have to say, sis, you know, enum dog get names, type of some enum name goes.

A

With get name so the difference is with get names. It's not returning me to the problem with getting values. Is you you have enough to go through the coast? My enum are a equal cast, my enum or a value.

D

H

A

Email and you're, like I, wrote my enum so many times on.

G

This also, what is there.

A

G

Of the Catania's method right now, I'm genetic systems, alright yeah, this then death today, okay, well, then there's a boxing issue as well. Well,.

D

It's not boxing yeah, it is system, it's actually a TV memory that has just been cast to a system everything, but if you actually give its elements there long yes system.

C

Not array is the subtype of every type, so it's not returning an object array, in which case each object. Each entry in the array is box. In this case it's returning a reference type where there's no boxer and then the contents of it are the actual T enum value. So there's no boxing you just make it.

H

C

D

But it's a very counterintuitive because we've been eliminating a lot of these like please pass this object. That comes back, maybe R as I've done there too. So.

A

I think this I think that this is going because it eliminates that the it makes the return type more concrete. It eliminates a place which is the same as saying it eliminate with you have to cast so I think that this just provides goodness good. You.

I

A

It's artificial there's! No, nothing tells you like. Essentially with this one you still get a if you're, not using var, the compiler will tell you the generic constraint and the destination don't match what get names.

A

It's really just a method, parameter that you're calling generically for no reason can.

C

You do this as an extension method.

J

Like yes, but it's all over war, but you want it for overnight right.

C

No youyou do you do an extension. You can have generic extension methods right. We can, but they you have to have an instance in order to have any special right, but I mean just do default default of whatever Don get values, not get values that.

B

Is that is honestly worse than where you come into it? I.

A

Think this provides goodness, and if people want to argue about the other ones later, they can but I, don't think that they provide enough value to add all right array. Okay,.

H

Value pair string to you know, I will say foot Boddington yeah if there's good values to with this same tards, think.

G

For like body feet would be nice to have good names, yeah I.

A

Guess the only other one, what does what's format? Look like.

G

The thing is that it always saves you from body in section little bit: yeah: okay, listen it's not too safe character. To me. The reason is parity like I will be surprised. Right, basically, learn to use this method and suddenly all should I forgot. They didn't yet add good values. Let me like wait. Five more years, you know lots of people closing.

A

And so forth, I actually think we should do it for format as well, because format you can use genetic generic inference on the value. That is the input argument and being able to use generic inference to eliminate a type argument, sounds very good. What's fun, do you eat them.

K

Ducks you know you got or Matt. Why don't just have a format instance method.

B

Just now, because it's it's it's shitty, if you can't discover how.

A

Is that different from to string because items are all art of weird are useful e ad? No.

H

You're right, it would just be to string at that point. Yes, it would be so nice if I could add to string overload that takes it automatically. No.

G

D

G

Refuses to use enums, and I have to keep fighting with it. I was even that on email thread today with Steve, because he commented on our. He has killed you some of the storage api's. He commented why the heck. Are you guys not using enums, because my team creates enums for.

E

Various reasons, including that we cannot add metrics.

E

It's alright, but if you, why, for that really so.

A

The current are the there's currently an enum that format yeah, whose signature is tight, object very and its generic on teen. um Then it will be team value in format. But how is that different than too short, which is whatever this out? There is an enum that format its.

B

Aesthetic type it's sitting right right.

C

But it ultimately just calls value dot.

A

Too straight okay, I mean if the answer is that it's already solved with that, we have a two string that takes a format and it's not.

C

My default two string returns the name and then otherwise. It takes the bat. If you specify DX trap, it returns the value, formatted and X decimal. So enum instance.

A

You know instances do have a two string that takes format. Yes, yes, and one that takes up format, provider and I. Don't I was just looking at the list of what he was proposing to genericized in and in the format has value because it, let's use generic inference to get compiler safety or and their generics plus inference for safety and eliminating an argument. But if it's accomplishing will be another way, okay, all right.

B

So I think I just have to pull it. So we said the first one is goodness. Let me just discuss what I'm hearing as we don't care this one. We said the various lower crystal set for parity. My care level is low. I can go both ways. This is one that Levi talked about, and then this is the same argument. Well,.

D

B

Actually take some points.

D

A

D

I did copy. The room house park is an instance method right. You know, yes, it's because it takes this and the flag. You want arrogance and it basically doesn't happen so.

G

H

G

This is a flat tire, but you know.

H

I mean uh whether you're twelve parks and stuff. This is what it is. Oh yeah.

D

Wow, that's a confusing, but now it's it's a generic instance method which I think has all kinds of weird behaviors in the German. So so.

B

This one had zero video, because the console looks very the same.

A

Well, but I think that we would, if we were gonna, do that one because we were trying to make it more compile friendly on static, has flag enum value comity. No, that's.

C

Or something yeah, because if you were also doing this you're missing parse, which takes a type in a string and currently returns an object.

D

It would do this so public static, Google house, Flagg, TV, no TV, no, that ass, TV and um flat, and so the enum value into enum test. Why do we want it to be static? Instance? Generic methods are very bizarre.

A

Well, Joe has an instance, an instance method on an enum. We would say that the we actually want the generic to be constrained to the enum mimic type already, because you'd want it to tell help you with, as you know, has flag a Flags enum type. It wants a parameter that is the same enum type. You want to constrain it on T those, basically essentially this like. If it's an instance method, we would have a non-generic and a generic that are the same in it.

A

I, don't think the compiler could reason about them, because they're equally preferred.

G

There should be, a constraint, can be reinterpreted casters.

G

D

We actually have that as an internal API like can I reinterpret.

H

House, listen, okay,.

G

You know that's what would solve all the problems that you know. People have only knows you could write algorithm. So very nice. You could do this test as a you know, reusable.

C

Routine I mean the JIT will already do constant folding. If you do size.

I

C

Enum equals equals four and then cast it to it. So it's trivial to write a helper method that does the right thing.

G

You mean I could kind of open code the cast yeah, but it would be for specific in on this work right.

C

No, but given given in enum, you can do if the size of enum is four, then cast it to int and return it you you, you can actually do that in its constant folded down and to the right yeah.

G

What I'm saying is that now you wrote reusable routine, it's only for this particular enum. It's not for any young, no.

I

No, you can do it for any, and how do you then? What's the type of the parameter you.

C

Know yeah te, no, it's just a name linearity, enum constrict where, to you know miss of immunity. All because of this new constraint, I said.

I

Yeah yeah I forgot.

C

About that one.

A

Yes, because it's the like it's the damn it there are things that I can do on Edom, so I can't take misconstrue.

G

Except it's kind of that's what I'm pointing out it's a bit unfinished because yeah there are things that I can do. I mean um I. Guess I cannot do anything, I mean um unless I know those tricks. Yeah yeah.

C

But that's also what things like that house, flag and stuff are for there, the gym there, the general purpose thing and as of 2.1 or 2.2 they're optimized in the jet to produce the code you would manually have written, which we can't do.

D

That in person or whatever, why not? We actually went through and removed all of our internal usability them doghouse flag, because.

I

It is not performant.

C

D

Because it had good performance but because method calls have larger IL than just doing regular bitwise operators and was causing so that it's no longer be available.

K

K

A

Sorry, Taylor all right, so let me s is defined as a as a tension method for something.

B

Well because it's the same name.

A

B

Oh get name already exists, that's true. Yeah I've missed this one.

H

Yeah this is this, is what about them.

G

Oh speaking, of which, today, why are these not the extension methods, Oh Tina.

B

Because it doesn't make sense, we booked them on in surgery.

A

Well, it names is give me all of the names that are defined for the Sina. You don't want an instant yeah, but those those is defined them is so has flag. Is, is already an instance or an exception. For instance, it's an instance, I feel and I, don't know, I guess the compiler would actually prefer the extension method because it would be a con and we'd count as an exact type match instead of the enum call, which is the base type match. So a maybe has flag as an extension method would.

G

Work and get name you know is, is it it is a different from constraint. I.

B

Was about to say I think I would never call get me again. We usability step for two straight seems well.

C

I think maybe two simpler I think the difference is that a two string goes through multiple steps of code logic that ultimately ends up calling effectively get name. So get name is a shortcut. If you know you only want the name of the value well,.

B

What happens in it's a flex combination.

C

I'm pretty sure that internally, the jet has handling yeah, but then, like I, think the way that works is, if there's an exact name for that flag. It says that flag, otherwise it returns the bit value rather than something like X or X or X. It.

A

Over criminal, all right I mean I'm all gonna cook, getting them name names. Some thingy else returned all so.

B

Literally just looks at the names, if it's a flex in and then it will not find it right all sorts of flyers. You know that it ignores at your cover, know get name will not.

D

B

Get name will not too sure, but then the behavior is different from yesterday's.

A

Amazing is this one exact thing who has a well-defined native that makes sense.

B

And that case, though, do we care then like oh, is that what we will propose.

A

So again, so it's get name it name, it is defined and has flagged. Could all the extension. Then we'd have to figure out what we're going to put them.

B

This term you know mixed in, but this is hmm I would not do that. I would honestly follow the crimping I'm gonna, all just etics yeah.

G

Maybe that's because then they show up you never intellisense on everything and they are kind of a bit corner case. Api's, no yeah. If.

F

You make house for an extension method. People would kind of get auto upgraded in many cases when they just recompile right, yeah, yeah,.

L

We there's some benefit to that. Can.

D

We define an extension method on the same type itself, no.

J

It has to be in a static.

D

B

But I agree with you that it's not a good constraint from the language yeah.

G

And I argued with the language team above this many times they say it's performance, yes,.

C

They don't have looking at every single type. They don't have to look at static types during compilation.

G

And you know, then that's you know somebody commented we could add those as extension methods to announce, but we don't you know we don't want to basically keep adding an extension holders yeah every single time. You want to add them. One method boom.

D

And your time well, which is why we could actually just have a generic like primitive extensions or something in the framework or somebody's.

H

Just just GC for that, oh yeah, it's in system or environment.

A

Environmental correctly, two plates that now hey all.

B

Right so then, there's.

A

A comment from drunken at PG of having.

D

Nothing screwed up and added a min, so it's going to do it yeah it's it's not the end of the world to have those are stuck all this stuff. It's alright.

B

Then let me go to this issue. I stand corrected.

A

All right, I will play the devil's advocate here and ask don't get values and get names return things that cannot be mutated so that we can make them where, if you call the new generic one, you get the same answer every time or didn't you say you know what you're asking for get names screw it you get using Inga rate freeze.

D

Time as a new or later every time, because we need to even said in the comments and.

A

D

About performance for these APRs, that's right: I asked the question where devil's advocate, except for a housewife house, why we care about performance and that's basically, it yeah.

C

I think, if someone wants to cash get names, they can do it themselves.

B

But somebody in shits that the constraint needs to be where it's dark or Mateen yeah.

C

If you want it, the difference is that we're we're underscore or we're enum is. It can be the system be known, type itself or any actual ena, whereas struct enum prevents it from being the enum class itself, because it's a class so.

A

Is that actually a lot of my I think it's I work to you know where Tina :.

B

Was struck how much.

A

B

I think that corner kisum takes all right. We public visitors going in you.

D

Public partial house.

C

I think the only thing that might be missing is the parse method that I had called out looking at what's exposed, because that one returns object where we already have.

A

C

A

It says on api's I've got net, we have parts of Tina, do we yeah you don't out of it.

B

Yeah, it's just at the bottom. It just what's different. I know.

A

B

A

It right about first yeah.

B

Good sir yeah, then maybe the.

A

Messy parts of typing string and then right above that partial generic.

C

Over te, no yeah I was just looking at the it auto loads to framework for eight in the doc website. Yeah you.

D

Should have done that as we fund, we should.

C

Talk to the docs team and see if they can change that to a 4-3.

B

Someone suggests that we should have a to object. It is dinner because it prevents boxing, but.

C

I, don't think we should, because to object, converts to object yeah if we were to have those we would I would think they should be like to in 16 2 and 32 etc. But you can just use the converter class for that. If you really want to well and if you want the I.

A

Want this long as this enum that's yeah, yeah.

L

L

You can't do that. Spears.

D

Look like us or yeah.

L

A

D

As going to send.

A

Your the right thing now, and just dissolve also that.

B

Pose yeah, that's.

D

Or just cast because that's free only if you're, not an American company, if.

A

You already have unsafe as enum, then yeah yeah.

C

Yeah we're interpret for you, could you know, use the the casting that the jet recognizes, which is cast object to object to T or yeah, cast an arbitrary te to object to concrete type in the jet special cases at and all those prizes with box for generics, trucks.

D

So what are we going to add? Const cast a favor, well I mean technically I. Guess that's what marshals for no.

C

We already have a unsaved dot as wrath, which.

D

C

An end and returns Iraq yeah.

D

Okay, so there's our hot spots.

C

And we don't have constant errs, you don't need to worry about it there and we have that mi Casas called dynamic.

D

This table is large enough for me to crawl and hide under it. You're.

C

Gonna end up hitting the metal of boards under the house. Maybe.

D

I'll knock myself out Rosie, look at so much pepper.

B

So then, let's those of you things I guess I have to do the same thing on this. This is if only I could find the browser window here we go. I can.

D

Edit your comments ago, that's perfect, as.

B

B

I have remove roads and seconds API. Do you know.

C

Why they get marked as and our needs more work or whatever at the bottom.

B

So I said need some more work because we gave feedback.

B

There was a get full person thing, so the person who opened it we said you mentioned you- don't want to use, get full power because you want to preserve which we let relative Ness. What's the scenario for this API and functionally, it seems, get full path or keeping the tariffs with God seems awful. Okay,.

B

Jeremie responds and says what you want to do is normalize a pair of segments without it being combined with the current working directory. If you called get a packet full path, you're going to get a path with the current working directory and added that to the front does API would give you back the original one. It just removes the dots between so.

F

The goal here is, it doesn't actually touch the file system at all, writes just it's just not just parses I, so.

A

Get full path uses CWD as part of the resolution, and this one. It's like I've taken a thing with some dot dots and some dots in it and I removed them and get over it.

A

I mean relative segments should be called source at destination.

A

Trade or path and destination, as we could say, path because it matches the overloads and boppers should definitely be destination. My name's.

D

Man as a capital, so it looks like what happened was last time. This came for refunded back to Jeremy saying like, can you talk about the scenarios more and then he responded? Yes, yeah.

B

So the way I send this in leading dogs will always remain because they can't actually do anything before touching the file system. So the only thing that would remove her intermediary ones, whatever.

A

India, dot, dots and intermediate dots, yeah.

B

Where the syntax, basically yeah it's what the housing.

A

Remove reading us what.

B

Seeing ones here right.

D

Because I I see the only comment I put in here was someone mentioned using it for URLs and I. Don't think that's a good idea, but no.

H

One responded: it doesn't just remove dogs.

G

B

Has a whole lips did thing: man, yes, but it's saying.

G

It's a big new client I. Give you second thoughts.

B

G

Then you just saying that the method I wonder what every home is the best method name. Does it does more than just remove relative segments in its collapsing.

H

It's kind of like normalizing, you.

B

Don't want to use the term normalization. I know, I know that it means something very different and it does more than normalizing action of a pretty fine. Oh, it's.

G

Because you know.

D

G

Thought when I saw the metal plane that it only removes them eating now that you started to talk about removing in the middle I realized that the metal does more way more than remove, and it dismissively can't remove the meaning of its chemically.

C

And it can only sometimes remove intermediate one. Yes,.

K

So I would not be able to.

D

K

D

Of the examples that was given was if you're working with a virtual file system, such as something within a zip archive you want, you, don't want something, that's bound to the actual file system in any way like the existing path, API czar, but this would give you something that can be used inside of that virtual.

A

B

D

B

D

Of it yeah, we.

C

A

Remove them from the middle so.

C

Imagine that you've got a folder named dot, dot, more folder names. You can remove the folder name, but not the dot dot. You have to move it to be part of the original, and if you had something like folder name, folder name, dot dot, you could remove one of the folder names and then compact everything else together, but there some times where you have to keep it and move it to be part of the initial, because, if you're a like.

A

A dot B, that's B right, whether you remove that one, if you're a dot, dot, dot dot me yes, Donita yeah, you know, so you have to keep one of the dot dots in that case. Well, any that remained would be at the beginning right so or there would be a series of them anything right right and.

G

A

G

Naming comment is more about all the other methods on path. They are kind of like I, don't care whether the resulting thing will. Let us is the you know, a proper path of the file system. You wanted, you know the thing to display it, you only the drive to began it's gone, and this one does way.

H

More in this one actually doesn't want less, because literally the only conversatio, it's looking at Dalton dog I mean get full note. Is.

G

Still good, because all there is semantics that we don't discard, but it won't be, is logically a subset of what get full this.

A

Is a string parsing? It's not it's! It's not aware of the file system of invalid characters of you know, just whatever it believes a path character is the only.

D

It's all some Charlie doing like total one. Whatever expansion, it doesn't try following no UNC, it.

C

Just removes relative segments which are dot dot dot. Those are consistent on all houses, so.

A

It could be called like remove redundant relative sentence and then maybe now we're actually describing there's a remove relative I agree does sound like if you gave it the path, not dot, that it will return back the empty string, but those are actually different. Yeah.

A

Maybe this is the adding the word redundant helps figure out. What it's going to do is again a second or minds casing, because it.

H

Does notification so what about remove redundant.

G

Segments from it about fidelity, those actually removes more than just relative. If you have actually do ain't that that it removes both that that that, and he.

H

Can the VM yes so remove.

A

Redundant and then on the try, remove we should rename buffer to destiny.

B

Excellent, let me paste this guy in then, and.

A

Then it had a reason for not you, therefore a preferred source, but then it said it should match the logical overload name: okay, there are those hoping for collapses.

C

Avert what is going to be the handling of this in a file system where one form of slash is illegal and the other form of slash is allowed and therefore you've got dot slash something in a name is there? This has no notion of a file system yeah. This doesn't make any peanuts at all right, but so how is it going to differentiate between forward slash and back slash for directory separator care that that directory separator says.

A

Yeah on UNIX, it's okay word, slash on Windows I said.

D

That's how I don't think it would use up? To be honest, I mean that's a good question for them. Jeremy.

C

Yeah, because this has to be aware of like on Windows, both are valid because you could have a UNC path versus a file path. And so it's forward slash on.

D

D

Or it could be yeah look I'm I'm.

A

Looking at the.

D

Actual comments, okay,.

A

Yeah so they're using UNIX, pathum, okay.

D

They would probably, to be honest, a would probably need our staff as well. The other thing is, it needs to be consistent across all platforms, because one of the core scenarios was doing stuff like zip and crafts timing. For that one, so I think path is fine, because then it matches the overloads.

A

Better dates and they use the same argument, if you say distillation, but.

D

That should be destiny and span to that event, sorry, let me let me let me rephrase what I read sorry.

K

A

A little bit special capital spend, they spelled spanner. Oh.

D

C

Yeah because, for example, an X for the only disallowed characters are no foreign slash struggle week. Just.

D

Know there's a call from a team that says both forward and back collage look.

B

At Hever of the generic.

B

C

Slash dot, backslash name, dot CS, which is a valid file name ah next, for yes,.

D

But I can't imagine anything. What does that in practice? I don't know they do all the time.

C

Like when you accidently tap into windows path and then run it.

A

On it say: well, yes, there's the person who does it on accident because they don't realize they're in a thing where it's going or it's wrapped in quotes, and then there are any hackers who are trying to write something that you can't correctly write, because the first backslash gets interpreted as an escape character. Well,.

D

Okay, so it's n times no I, don't necessarily care about our framework, behaving correctly when it sees a file system that someone has done weird stuff doing yeah losing what's support over the.

A

No because that's gonna call the spice method, which we said returns my cold slice maxilla, because Charlie doesn't have a slice method. What.

D

Happens when we add an industrial cut.

B

Again because it's hard it's on in borås.

D

If it's a type declaration subjects.

H

We can have a static index earth to charm if it did dip. My that's a type context. That's not that's! Not an indexer all right, Christoph's, proposing a new type. You.

A

Think- and you know I will say with the current spin.

A

Is where you gonna put the read only.

H

Linguist get one yeah, but if you don't leave tired call.

D

This talking about itself cost okay.

H

Because it continued under no, it's.

A

Called in sharp.

A

I, remember all the Rideau knees. It's it's a cost slice of constitute. Oh well, that's the Midori.

D

Wasn't that terrible.

H

So we're already more yeah, so we just and.

A

Then everyone was debating on what the implicit one should be.

D

Or if they already have like file system API, so don't be thinking when they seem like weird characters in towns and as.

D

You know this Nathan, while you were out fairly folks, want.

A

Access to the raw or a vacuum, us taffy, no very much. No, that's exactly the guidance that I said. Do not do do not give underlying access to the thing, because, as soon as you resize, it's corrupt but.

C

It's not corrupt, it just doesn't modify it anymore, but if it uses the array pool, you have destroyed the others. Yeah.

A

But let's weekly right, but my it's like the reason for that is, if you ever give anyone access to your internals via spam.

A

If your internals are ever allowed to change such as list which grows yeah, then your program is now in a very non-deterministic state right, they'll end up with oh I called the s span and then like I'm doing things and then like I added more things and like some of these things, work except if you hit a list, scroll pounder, it gets weird. So, like you know, we should never happen well,.

C

So literally, never, but the proposal here isn't add it to list it's to add it to a special runtime Interop services, collection, Marshall class for performance, critical scenarios for performance, critical scenarios don't take lists.

C

But what do you suppose? What do you propose? People use for a dynamically grow? Bull selection. You.

A

Use the array you call the resize yourself and then you pass this fan. It turns out. That's exactly what this does, but don't use list use the thing that you control the capacity know if you're in highly performant scenarios, you will write as ugly code to do it I'm fine with that. This is no.

G

Solution to this problem collection, it sees you and you know, a list spam which points to lists and stores index in many it's not as fast, but very much. Basically, you add a dedicated time that stores reference to the holidays.

G

Unless tree you type yeah kind of yeah.

F

Really, this is a symptom of not having something like a list builder type pool. There are so many people who want some sort of global array and end up handwriting it. When.

D

When this came up for review initially, my biggest concern wasn't actually the like safety aspect. It was the fact that we're now saying conclusively, list of T has to be packed by backed by contiguous memory, which we've never officially said in the past. Yeah.

H

But we would never change it. I mean the good common characteristic change for regular usage, at least a few. So remember, stringbuilder used to be until recently backed by a contiguous memory, and then we decided.

D

It was faster to talk because you don't index in consumer in there right.

C

But list list is required to be yeah, oh of one access time. It's required to have amortized no.

D

It's just that.

C

The spec says required to have oh one indexing, not just amortized, it doesn't say amortized. It says it must have quantity, x-h, back Yakima, 335 spec and which has the TR 84 subsets, which defines the corland types and their required implementation.

B

We gotta say this I think idea: what does that list of T is the general tab which was supposed to be this super low overhead, Goa right, I'm, real and.

C

Most other languages expose some way of getting a view of their global types. Well,.

B

The other thing is keep in mind. We had other API skip last four on list of T, like moving other things that we said well. Where do we draw the boundary right and then the suggestion was well to give them a generalized. We have to do it and this would be the control and.

C

You could do it, you could do it simply in all the cases except for where someone gets a snapshot of it and then on the same thread, grows it and then tries to access. The underlying spam wasn't even be able to run well.

D

L

Don't see these types.

F

C

Safe, so that doesn't matter oh yeah.

A

So I really really really really really good, really very good, really good and.

G

They're not that I'm into the issue, not threatening to say yeah I, understand problems with API, but I. Don't.

H

Code when I was thinking these, it would be nice if I couldn't method like this, but there's spend on orders. Let's talk coffee to go yeah.

C

But you don't want to have to keep on creating another copy of an array just to be able to use it in some other method that takes a span, etcetera so.

D

This is really useful for doing things like a mutated, the list- I guess, because otherwise you would just get a read on this game right.

C

And the only place where it's corruptible is you're either doing multi-threading, in which case it doesn't matter whether you should expand or not. You can just cropped it. These aren't thread safe types or you've got a single method. Where you snapshot the span, you grow the list, which causes the span to no longer be valid and I mean the guidance. There's basically don't create a span and then call other methods. Well, I think this the ones that.

I

G

Memory is kind of let's say, because you can store memory for later, so you don't have to be like in one routine doing the really stupid thing. Yes, you can just store it for later and think that it still represents the list which it doesn't the one who do spam. You would have to write code. That is pretty damn, like you know like in the same method right or on the same contact. You modifying the list. While reading this man I mean.

A

Like I feel better about this, if what we're doing instead of saying as fan is we make lists be in a book, so we have to get like we make it so that it has an extension somewhere the get reference and you can put it in a fixed and then you can build this fan yourself like we gave you access to the thing as a pointer and like life is override okay.

A

Well, we can now print essentially yeah, but to me that seems better than making it as semantics, like you had to go out of your way, you put it in a fixed statement like like you. It is a I mean I am doing nonsense. I am going to deal with. The consequences is.

C

That a team or nonsensical, then adding using system runtime Interop services, which automatically puts you in a I'm, doing one same shape and then but no we're all in here.

I

Does it say unsafe.

C

I mean we have you sing like dangerous as spam? If that solved your problem, that would solve a little bit of my problem. I'm.

B

Actually is basic that would be, it is already like our community doesn't understand, join list.

D

B

We haven't that's an argument than all the Marshall API the problematic, because one.

D

Of them say not necessarily because good like go on Stack Overflow, for instance like when people see things like in pointer or void star on the existing Marshall class, like they know, Oh in pointer. This is not a type I'm familiar with like pointers. Pointers are scary, dangerous, whatever like.

D

If you go on Stack Overflow and just look up stuff, you just look up people using the memory marshal class like people, don't realize that that's actually type safety violation, it's left and right from that glass like people just Co memory, Marshall nothing in here looks dangerous. Nothing in here has any word that tells me that there's danger so copy and paste this answer. The past 2000 uh votes, yeah.

C

Well, in Young's comment: was they shouldn't go on memory Marshall and it should not be an extension method and are not extension methods because they they want you to do the additional typing to get access to it. Yeah. Why.

D

C

On the memory matter,.

D

It doesn't deal with oh yeah.

C

It doesn't deal with memory or span directly. It deals with giving orders beyond, apparently.

D

We don't want to use that tightness like a dumping ground for all all.

H

Are like give me big intervals? Well, no! No! It's it's a time for dealing.

G

With spans and memory whether there.

M

Are inputs around.

M

A

So I mean it would like to me this. This feels very much like we just okayed the guidance that says don't return to span unless it's an input argument or a constructor argument, which is an aquarium. This is very much not that this has its own buffer. It can move its own buffer. The moment you get back to spam, the universe like yes, we can say well, it's your bug, you're the idiot who got this pan and they call dad.

D

To expose us first off, why did you let's find in memory directly like why don't just give out the array.

B

L

Cut out spent over.

B

No because you can't represent the thing that the array is bigger than the count can this is let's talk him the same.

A

Way we did with memory. No, let's.

B

Pan gives you both yeah, so the same memories.

A

You don't have anything more for what array am I representing right now than erasing the memory Marshall try and get array, you give it the memory if it is a ray back that says, here's an array segment. You started here and you went that far, but.

D

I don't understand, though, why why we want to use these like base types? Many things actually got whitey right, because.

G

It gives the thing that actually represents delays. It does not do basically, the list is not the range is list and some empty space. So every.

H

Second of T would have a span words because arrays actually have wider ecosystem support. You know.

G

Brandon, the Jeremy is saying or any segment of T you can store for later. I think the difference here is.

C

G

18 yeah I said I would not end memo. Yeah I will just add the one. That's widows, yes bad! Yes,.

E

Then, basically,.

G

You are in the same thing you know kind of around and if you call add you know, it's I mean people can still do it. I agree with you, because people may not be aware that a single ant can invalidate this fan. But at least you know it's in your code versus memory can be kind of dangerous because you fish it out and then you store it for later and there's.

A

An instance method or extension method. My answer is hell: no, if it's a collection Marshall, we promise we're, never gonna make it an extension method. I would prefer the more dangerous being it somewhere. If we believe that Marshall says that Levi says people don't actually understand that. But again the memory one is know like you, you already have a span. Factory list is itself disband factory. Once you have the a span, you don't need. The second span factory well.

F

I think they they accomplished the same two different things right like span is I want to operate on the contents of the list, whereas memory might be I want to use list as a global buffer to pass into IO. Sometimes.

A

Well, yes, but that's exactly the thing. That's super duper dangerous because any other Call list that means no one's reading the memory that you were messing up anymore and I think.

C

If you really want to do something like have a memory just ask the span around and when you need this or past the list around when you need to spam, yeah.

A

If you want to make a memory, you can make your own memory manager that takes a list and all those thing when you can do it. I could imagine something.

G

Like you know, I think it's too late. Api is that kind of consume, something like place? No, we go butter and gives you give your memory of T and now your list.

G

You know what I mean where you're kind of use it as a growing room bathroom. Now you want to pass it to some ApS that accept the memory.

A

Of T, we would need to make something- a ghost which tells it clear, doesn't mean set count to zero. Clear means, like really give up is already like your dumb disco, like women, need a oh and I'm stealing you arm again.

D

So we're clear, currently housing behavior, where, if the T has references earlier.

A

On zeros and I, was it be nice.

D

F

Exactly suspect to move semantics.

G

You know this will be like the Builder, like you mentioned, before, ability we.

I

Don't have a builder.

G

In a sense that I kind of can use it to build and then get memory of the items, yeah.

F

G

F

Was memory of items.

G

Is consumed by many guys, and it's not you may not, because yeah.

F

I think span is a good escape hatch for people that want to do. You know like there was that insert into or moving values, making the arrays.

D

That's where the salt point.

F

But memory I, don't think, makes sense, I. Think memory, something more like a list builder, would probably accomplish what people want to use it for well yeah and.

C

Instead of as memory, there should be as read-only span because a span has to increment the version count, assuming that the user will modify the contents but, as read-only span avoids the version count increment well,.

G

Except the version was meant for innovation, for, like we resize that, therefore,.

C

It kind of is, if you set any element, the version count increment the index are actually updates it. So.

G

Yeah but I think maybe it was overdone the reason for it was that if you and no matter it and things get removed or even added right, it's kind of hard to have explainable semantics. If an item changes when you and meriting who cares you just like you called it too late, oh yeah,.

A

F

If we're holding people's hands with safety rather will be consistent, since we already started one way of doing it right now, yeah.

A

I mean really the question: if we don't have a scenario where we actually need the writable span of further read, only one see how guys can see in genomics bamboo again.

C

Well, the reason for the mutable one is: we've had requests for things like move that way in a single operation. You can remove an ad, in which case a span covers that and all those other api's people now have a way to build that as long as they're not growing the back in the right, I.

I

G

Even with my own sword at least more efficiently,.

H

Correct this would let you do it so.

A

Every we just need to decide. Yeah I mean it's fine to say a span bumps them they're increments. The iteration count Negra for each king and you call that a span. Probably we just shouldn't. Let you do that.

C

So I think that's yeah. So basically your feedback is make sure that it's known it's dangerous and don't make an extension or instance, method and don't make the memory work. Yeah.

A

And no memory version, yeah I can see the reasons I really don't like it, but if it's super out of the way and I'm going to call that then lets you do what you need to do then I. But if list itself had to like here's my list as a span but like that would just be yeah.

D

Whatever happened to the proposal for like the requires unsaved attribute, I.

C

Don't think it's ever been seriously proposed on the C sharp line repo, so you can only call it in a non-safe. Oh yeah,.

A

That would be I've been to 96 just yeah. We talked about that of like we can do this by it also takes we start ignored and yeah it. You have to do something to test.

C

Zero, because it's early enough in the cycle that we could seriously propose it to the language team and reasonably see it get into da at five. If we were serious about it and Don at five is a major version, so we could theoretically add it to things like unsafe and just tell people you're moving to a new new major version, you're going to have to.

A

Update your app by going this and they would just moderate the thing so older compilers yep.

L

Another could be behind the morning wave anyway. If we really would say one thing: yeah.

A

Yeah yeah I would be happy like if this is behind it and again that's where I was like. If we make it the the thing that can be used in a big statement. Pattern then, like you, had to write unsafe code in laughter, but you can do it without writing unsafe code. This is.

C

Well, vote the weird thing about the get printable reference you can use it without writing. Unsafe code compatible.

D

Ruff, we actually said get pinnable. Ruff can always be safely. We don't have any types of having a printable reference method that ever violates.

A

Always cheese by being renamed it from get dangerous, yes, but if you, but that gives you the right to zero well, if this one doesn't violate.

G

A saucepan you'd.

A

Have to use that.

C

Yeah memory Marshall creates pan wrath, list.com.

H

G

H

D

H

Exactly so the whole time type safe in the.

D

Sensor, yeah I.

B

D

A

Is it worth that in guys we don't lean, there's a primary thing, or should we just let this fan drop the read-only.

B

C

B

C

Is whether the version count is incremented here, you basically yeah you're, basically saying I'm going to mutate this or I. Won't you take this, and so it's safe to continue a numerating or it's not, and then those are both these static methods yeah except this yeah, and if someone really wants to create a memory from it, we have memory marshal api's that people could do dumb things with well again,.

A

You can make your own memory, you can make a memory manager type that takes the list yeah and then your span, you just you call this an span. Factory often the memory. Do you return that? It's all you can do it?

A

Yes, you could.

A

This method is a up.

F

So what prevents this class from becoming the next memory marshal class, where people use it without realizing that they can do bad things? Well,.

D

For one, maybe we actually push the requires unsafe yeah.

A

For one, this could only work on the collections that are defined in system :.

A

B

Only isn't much diplomacy, we already have types collect memory monster which allow it to like shoot off your food very easily. So yeah.

C

B

That's why the naming conventions already there like nothing, I mean much less dangerous anywhere but just say yeah. You just take memory. You do bad things. It's.

C

On interrogates, on runtime and in drop services, so it's it's! The namespace used for low-level.

D

Stuff yeah the the problem- and this might be a weak argument against that, but I. If I'm working with a long ish file, then all the namespaces were going to be at the top system, one time in turnoff services and I, don't necessarily know you know 2,000 lines down in this file that I've pulled in API server, potentially.

B

No I don't think it's in. Oh, my damn. It I just think that it also means that the type name itself has to be designated and he used mocks. What to basically mean things you do, that is interval, P and so bad things might happen. If you use it yeah.

C

And I think Marshall in general conveys that I will just add these methods to my life.

F

That's what I was getting it and like what do we get from keeping it necessary.

B

I think your argument was slightly like the other. The memory marshal our beliebe and this one's are not quite as bad, so you point them to the other thing. Well, this.

I

One is not as bad.

I

B

That some collection more memory much so and.

C

I think the big difference is, like matter marshal, is really around doing like really low-level stuff with spans, whereas this is creating a span from a collection, and there may be other collection types where this is useful in the future and there's a centralized place to put those.

D

One other consideration here is with the introduction of this API. We are permanently foreclosing our ability to ever vassilissa to be by an array all the way we.

B

Just think we generally don't think this again, because bad things don't happen. People do yeah.

C

I think you're I think if you make notifications like that list of T you're going to break WPF and win forum, and so it's it.

D

There was potential to do it safely, even though a list of T is you know, even though we didn't design this I could sell for safety, but it means that we can now never even have that discussion going forward. Maybe.

G

That's okay, yeah I. Remember we had incorrect at slab or maybe still have it's kind of like a builder. It's not even the class. It says truck I just want to keep me like that. I'm gonna be like you're doing stuff and then I want to get memory or span. You know what.

B

It's the same problem, yeah.

G

But it says: track yeah, yeah I need to be very careful that I don't pass it by value and so on and so on. Yet it is the way to do some of these accumulation things it's an implementation type. For me, too,.

B

So we're gonna make squeeze head is a major symbol. All right, you can't have a tired that is, that is getting the arrays from a pool that basically is a struck because it's like user for free is like you, you 99 percentile, now well,.

G

Except if this time doesn't exist, then I have to implement the same called anyway right, but yet, which.

B

Is still better because it doesn't Nick the entire ecosystem and if you be vitiated by the stringbuilder thing,.

G

You want everybody who does it open code? It no.

L

Because it's very loose.

C

Where your friend, over yeah and there's language, proposals and designs in the work that should allow you to have better ownership, semantics of rafts yeah, if.

D

We, if we actually had a concept of group, only types like I, would feel much better. Okay, I'm, actually making value sure no problem anyway.

G

I'm not talking about the chamber that I'm talking about he better well, no, you shouldn't over similar to go to be alright.

H

G

Very often I either time that is basically a collection. You know any of yeah.

C

This is like the same issue on why we can't currently expose fixed size buffers over an arbitrary type and things like that, and so so.

I

Their little semantics usual have you talked to John about it. Cuz, that's another thing: I talked to him many times about it and I mean we. Can people discuss number one for yourself? Are we still streaming we're.

B

Still streaming yeah? Okay, so you can't about Joe. Yet.

C

As far as far as I know, Jarrod's still working on the proposal or how to improve rap and how they can do good scenarios.

D

Like that, there have been some some interesting edge. Cases of Jeremy Kay found them earlier, while working with things like path, path, segments path, goal or something like.

J

D

There there are some fundamental things like that: they have to work through those yeah, those ones, good, yeah, cuz, Jeremy,.

J

C

There's purple.

J

Things on my end,.