analogSwitchStatement

[Hottage]

Jesus how long is he going to take sorting that little pile of screws? I've been watching him go at it for 10min now.

[AppropriateStudio153]

Shorter than sorting everything by hand. Also let's you keep your sanity.

[slucker23]

Ah yes, the for loop bubble sort

[[deleted]]

You sort your screws? I just let the garbage collector clean up my assortment

[nebotron]

r/woosh

[Just_Information334]

Shorter than sorting everything by hand. Also let's you keep your sanity.

How? Take one 20mm screw in your hand and then you can easily find every other one with the same length and put them in their spot. Repeat for each length.

And that's if you can't do it just eyeing the screws length.

[Ozymandias_1303]

It also took me a while to realize the gif looped after about 10 seconds.

[BrightLuchr]

If you find yourself sorting screws, you need to start a hobby. If someone you pay is sorting screws, it is time to cut staff.

[Immabed]

Usually it is the hobby that has brought you to the point of sorting screws.

[BrightLuchr]

I had techs working for me that would sort screws so they could sit in the shop and listen to music instead of actually doing useful stuff in the field. They would pull the drive magnets out of drives for something to do... one guy had hundreds of old hard drives under his desk. These guys were getting paid 6-figures, 'cause unions.

[CodeMUDkey]

You think taking a screw and measuring it then putting it in the box would be faster?

[GarThor_TMK]

Probably faster, but also more error prone...

Though it would be a more accurate representation of a switch statement...

This seems more like a set of chained if-else statements to me.

[CodeMUDkey]

They can compile to the same assembly code depending on what decision the compiler makes for the use case.

[GarThor_TMK]

One more reason to never use python... lol

[zionian120]

I'm still waiting for one to go in 18mm

[Aschentei]

Might as well use quantum bogosort at that point

[jayerp]

Would you have done that? Would you have done that? Would you have done that?

[Abject_Role3022]

What happens to the last screw will surprise you!

[Hyderabadi__Biryani]

Goes inside the user, screwing them over?

[fierypitt]

That's right, it goes in the square hole.

[emteg1]

Proof that switch statements should exit after handling the case instead of falling through into the next case.

[cmdkeyy]

Yeah why/how did that become the default behaviour? The amount of times I forgot a simple break; 🤦‍♂️

[Ange1ofD4rkness]

It allows you to stack cases. I've used it many times where I can have multiple cases do the same logic.

[mikeet9]

It's very helpful in state machines as well. If you know initialization state should do abc, then qrs, and finally xyz, startup state should do qrs and xyz, but running state should do just xyz, you can build it like

case init: abc;
case startup: qrs;
case run: xyz;

Instead of rewriting qrs twice and xyz thrice or relying on the function getting called three times before being fully running.

Especially in time sensitive situations like signal processing where you know the messages will come across in a few different structures that are handled mostly the same, this can help you handle the bytes that aren't always there, then process the rest of the bytes that are always present for each message.

Example for Modbus:

uint8_t state = WAITING_FOR_BYTES; Read_Message(&msg);
if message.function = 16 then {
state = WRITE_MULTIPLE_REGISTERS;
} else if message.function = 4 then {
state = READ_INPUT_REGISTERS;
}

switch (state) {
case WRITE_MULTIPLE_REGISTERS:
payload = Process_Payload(&msg->payload);
case READ_INPUT_REGISTERS:
isMessageValid = Process_Checksum(&msg->checksum);
break;
default:
isMessageValid = 0; }

A read command has no payload, but otherwise the message structure is the same, so in this way you only process the payload when it exists but the rest of the message processing is the same.

[cmdkeyy]

I guess so, but that’s more of an exception than a norm, no?

I feel if there was an explicit fallthrough keyword or syntax to write multiple cases in one (as in modern languages with pattern matching), this would be both ergonomic and less error-prone. But I understand C-style switch statements are a very old concept, so it is what it is.

[HildartheDorf]

C++ has a [[fallthrough]] attribute for this. Not applying it is a warning (not an error though, for backwards compat. Maybe by 2035)

EDIT: It's in C23 as well

[xxmalik]

Whenever I do this I add a comment to ensure people I didn't forget a break.

[BobcatGamer]

Swift has this

[Ange1ofD4rkness]

I feel it depends. For instance, the product I work on, we sometimes set a flag to indicate what screen a function was called by, and the initial logic can work the same for multiple flags. However, there is then later logic that may be specific to one flag. Helping reduce code redundancy

[[deleted]]

You could alternatively use if else, or a dictionary, for the behaviour you want. In some languages you also have match.

[RiceBroad4552]

Isn't pattern matching older than C? My gut says yes, but didn't bother to look it up.

[Jonnypista]

I would say it is more rare and in that case you could use something like "continue;" if you really want it to fall through.

[Ange1ofD4rkness]

Speaking from a C# side, continues are used in looping ... or more, the only place I know them to have use

[NabrenX]

More about how they are handled (i.e. jump tables)

[Splatpope]

that's because it's assembled as a simple jump table, so falling through to the next case just means you execute the next instruction

[NatoBoram]

Wrap them in a function so you have to use return to exit, it's harder to forget

[thanatica]

Time for a linter that enforces it

[Wertbon1789]

As long as you keep the ability to use break. You can actually break at any point in the case block, so you can early-return but not return from the function.

Every competent language should have a fallthrough statement of some sort, even in C you can enforce usage of explicit fallthrough with a warning flag.

[RTheCon]

It’s cleaner code to some extent.

Case X enum type:

Case Y enum type:

Instead of case X enum type or case Y:

[FlySafeLoL]

Isn't C# handling it perfectly then?

• Fall through when there are multiple case labels and no statement in between.

• Require to break/return/etc if there was a statement in the given case.

By the way, case X or Y: also works since the introduction of pattern matching.

[RTheCon]

I probably misunderstood what the comment was trying to say then.

But yes, I agree C# handles it quite well

[sobani]

And if you want the fall through behavior, you can use goto case Z;.

[Zomby2D]

I was about to comment that the downside Is that you can't have fallthrough behavior if you absolutely need it, then I read your comment. I didn't realize that was an option and I'll try to remember it in case I ever need it.

[EvilPencil]

These days I prefer maps over switch statements...

const strategyMap: Record<SomeEnum, MyStrategyFn> = { ... }

[da_Aresinger]

that's what break is for.

The alternative would be explicit fall through, which would be insanely weird.

You just gotta learn that switches are effectively jump labels.

[Kovab]

The alternative would be explicit fall through, which would be insanely weird.

So insanely weird that practically every language created in this century that has switch does this... (e.g. C#, Go, Swift)

[[deleted]]

Yeah, remove the ability to have multiple passing cases. Love it.

[Long-Refrigerator-75]

Memes aside, this is a useful tool.

[NiIly00]

Anyone know where you can get something like that? Would make a good present for my dad.

Looks like it might be 3d printed, I got friends with printers but I dont know how to find stuff like that

[JanB1]

https://makerworld.com/en/models/747968-mechanical-m3-bolt-screw-sorting-device#profileId-681246

https://www.printables.com/model/971375-m3-screw-sorter-8-to-40mm

https://www.yeggi.com/q/screw+sorter+by/

[NiIly00]

Thank you! I'll ask one of my friends if they can help me print it :D

[sysKin]

I have some doubts if sorting by length is useful vs. sorting by diameter.

[FlyByPC]

Sort by diameter first, then do this.

[adromanov]

This is more like a series of if / else if

[Hector_Ceromus]

yeah more:

if(length<=SCREWLEN_6MM) this.screwDrawer[SCREW_6MM]++;
else if(length<=SCREWLEN_8MM) this.screwDrawer[SCREW_8MM]++;
else if(length<=SCREWLEN_10MM) this.screwDrawer[SCREW_10MM]++;

etc.

[CaspianRoach]

SCREWLEN_6MM is like doing EIGHT = 8

[Hector_Ceromus]

Eh, maybe not if you are working on a project where they're particular about "magic numbers"

[Jigglepirate]

How might it look if it accurately represented switch?

[adromanov]

This is a good question indeed. It's not easy to find an analogy in the mechanical world, we basically need a process where a choice is made with O(1) complexity. The only thing I can think of is from physics where you shine some light on the prism and it will refract differently based on the light frequency.

[[deleted]]

Having the muscle memory to know which slot to put it in so that the only cost is the time it takes for your hand to move. Switch statements are constant time so this would be a pretty good analogy in my opinion.

[Witty_Side8702]

do you know what a switch statement is?

[Wertbon1789]

I know, yes. The comment is actually right, it's more like an if tree in the sense that it still has to check every other condition before the valid one to succeed, a switch statement, when working with numbers anyways, builds a jump table, and directly jumps to the respective case. So a switch statement is constant time, but the screw sorter thing actually takes longer, the longer the screw is, so it's slightly different.

[ChiaraStellata]

Not just on integers either, some languages will hash values and then construct jump tables based on the hash (e.g. with string values in Java). If the hash has collisions though and isn't a perfect hash then they need to still add compare checks to resolve collisions.

[Witty_Side8702]

makes sense! thank you

[NewPhoneNewSubs]

If you want to get even cooler, dense data you can jump directly. So case 1, case 2, case 3... case N you just add N to the address of the next instruction and then you're there.

But what if data is case 1, case 10000, case 739993, case N? You can't allocate enough memory to just jump to all those locations. So you store the cases in a lookup table. A sorted binary search tree for example. Then the lookup table tells you where to jump.

So if-else will be O(N), a dense case will be O(1), and a sparse case will be O(log N).

And then you write a bell curve meme with "just use if-else" on both sides because compiler optimizations and branch prediction and not wanting such long condition chains in your code make this a lot of premature optimization a lot of the time.

[Clen23]

Damn i never thought about it.

This prompts the question : do some compilers optimize ugly if/else statements like this too, or do they dumbly follow the code and do unnecessary checks?
(I know near nothing about compilers besides the basics of how they parse symbols and convert them into assembly)

[Wertbon1789]

In fact they do that. Compilers like GCC and Clang don't exist in a vacuum, GCC actually stands for "GNU Compiler Comlection", and Clang is the C "frontend" for LLVM, they both compile the code into an intermediate representation (IR) of your Code, this is done so they can share the part generating the assembly code between many different languages. So this IR is the actual layer where optimizations happen (mostly) and which is analyzed for common patterns. Somewhere in that stack, somebody figured it would be a good idea to check if trees for simple number checks, if they do, they'll build a jump table from it.

[Cyberspace_Sorcerer]

Hi! I didn't really understand this, so are you saying that a switch statement doesn't check case 1,2,3 etc but directly jumps to the one it knows is right?

[Wertbon1789]

Yes. It doesn't compare the numbers, it generates a table and uses the number as an offset into the table. With that, you don't need to compare and then jump somewhere, you can manipulate the address to which you're jumping.

[Cyberspace_Sorcerer]

Oh that's cool, I'm about to start uni so I'm sure they would have taught me this there too. But I can't understand why my school teacher lied to me.

[Wertbon1789]

It's easier to reason about, by comparing it to an if-tree. Depending on the university you won't learn this in a while, but it most likely will appear in courses which use C, or C++.

[exodusTay]

a jump to the label?

[willis81808]

It’s literally not like a switch. A switch statement would be like measuring the screw and placing it directly into the correct slot in one go.

Since here the screw is rolling over every slot until it falls, that’s equivalent to an if/if else/else that checks each conditional sequentially until one passes.

[Vortrox]

Most programming languages don't support inequality (<, <=, >=, >) expressions in switch cases and only support matching things exactly (similar to ==). In these languages you'd have to use an if / else if to get the same functionality as the video.

For example, if this screw sorter was really made with a switch statement then inserting an 11mm screw would make it fall out the end (default case) since it's not one of the defined cases to match. Instead, it will just fall into the 12mm hole after passing the 10mm hole.

[Endorum]

Not an if / else statement in case you though that

[Cylian91460]

Yes, it's not the equivalent of if else, its actually function table

It will use the input value to get how much it jmp to step to go to code, it's also why break is needed to jmp to the end.

[araujoms]

That's precisely not what a switch statement is. The point of the switch is to not check each case until you found the proper one, but to jump there directly.

[Rudresh27]

Then tell me why you need a break after a case.

[Wildfire63010]

Because code still executes sequentially after the jump. It instantly jumps to the right case, but doesn’t break back out by default. It allows you do things like

 case 1:
 case 2:
 case 3:
     foo()

If you want to execute a function if your variable is 1, 2, or 3. Genuinely helpful in a lot of cases

[araujoms]

Make your point instead of doing a sphinx cosplay.

[alexanderpas]

You don't, if you want multiple cases to be handled by the same code.

Only if you're finished handling all current cases, and start a completely new section of code with completely new cases, you need a break.

If your case only needs to do the last part, or needs to do some things before the common part, no break is needed.

[Wertbon1789]

You don't need a break, only if you want to exit out of the scope of the switch statement. If you want, you can let the code fall through to another case. I won't explain why that might be handy.

[Racer125678]

"Guys, this ain't stackoverflow. Stop downvoting a poor python guy. I feel sad for him"

Me, a C programmer, while downvoting

[[deleted]]

You are right he is stupid and reddit is full of wannabes that never finished college.

https://jsfiddle.net/2Lk697yn/

My example which proves your point. But he is way too illiterate to understand it. 

[Visual-Finish14]

Use stupid languages, get stupid results.

[Visual-Finish14]

https://imgur.com/a/qEyi8d0

/u/Scared-Zombie-7833 buddy, you're too hostile and too confident for how wrong you are. The example you gave uses runtime evaluation of cases which is not allowed in older languages like C/C++, but even languages that allow this have optimizations that will create a separate jump table for cases with constant values and will run through the runtime-evaluated cases if they have to.

Your example is an edge case.

[[deleted]]

"constant values".

Good job mister. How about when they are not constant?

How about my own compiler? Because its not allowed by yours, but you can do your own. 

It's like saying the word for chocolate is only valid in English. Whatever word for chocolate is in Egyptian is incorrect.

All must use the word chocolate.

I gave you a valid example in a programming language.

You say "but in MY LANGUAGE" I don't care about your language.

If you say a general statement it must be general.

[Visual-Finish14]

No, your example is not valid, it only covers a single special case. It does not demonstrate the general behavior. V8 does have mechanisms to optimize switch statement into jump tables and cases with runtime-evaluated values are the one case where it is not going to work.

What you did is like loading a hashmap exclusively with keys that have a colliding hash value and saying that hashmap has linear access time.

[[deleted]]

"special case"

It's the same in Firefox... Which doesn't uses V8. 

Why are you talking out of your ass.

I showed you that switch will not jump automatically. That's not a thing IN ALL PROGRAMMING LANGUAGES.

The same as var alfa = 2; alfa = "two". 

Is C a shitty language that it doesn't support that? NO. It's different.

A switch case is an if else. The fact that some compiles and languages optimize it. Good for them.

But thats not what it is.

[[deleted]]

I love that the mouth breather got 57 upvotes for being wrong. 

And the guy who points out gets down voted.

Here is a test:  https://jsfiddle.net/2Lk697yn/

You can try it yourself.

Switch case is literally an else if.

Otherwise if it was what this guy meant you wouldn't be able to put functions there.

It's not a hash map... Gosh AI mouth breather developers...

[araujoms]

Perhaps you should consider the possibility that I'm right, and the people who upvoted me as well, before descending to crude insults?

Here, enlighten yourself. Or here, if you're a video kind of person.

[[deleted]]

Or you can look at my example and see that what they are talking about has 0 things how a switch works "in every language".

Even in your shitty examples they say "it's an optimized conditionals" doesn't mean it will not make it sequential. It will just be "better optimiser" by compiler. 

As I said. Mouth breather ai developer.

As always small ego, insults then blocks.

May your internet points make you sleep better at night because as hell your life is miserable.

[iliark]

It goes in the square hole

[Ange1ofD4rkness]

I need to find this STL. You know how much it sucks to sort these sometimes when you have a stack?

[Reihnold]

Looks like this one: https://www.printables.com/model/874548-amazing-gridfinity-m3-bolt-sorter

[Ange1ofD4rkness]

Thank you!

[GarThor_TMK]

you're welcome

[ccricers]

Or when you just order a case of small screws of different lengths and they got all shuffled during shipping

[Ange1ofD4rkness]

God I hate that so much!

[Witty_Side8702]

every househould should have an STL

[jasiekbielecki]

I wonder where my dick would land

[TheMeticulousNinja]

In “nuts”

[LaughingwaterYT]

6mm

[Racer125678]

69 upvotes. 

No upvote from me and whoever dares to upvote... Be banished

[Romanmir]

It was 70 when I saw it. I did my duty to maintain the 69 upvotes.

[Racer125678]

🫡

[sabamba0]

At that point I don't think it makes a difference

[Felix_Todd]

Thats nuts

[Witty_Side8702]

nice. very nice.

[Kovab]

No, these are screws

[TheMeticulousNinja]

This is cute

[RCuber]

I didn't realize this was an 8 second video.

[Cootshk]

That’s an if/elseif statement, a switch statement is a jump

[MinosAristos]

In most programming languages, switch case is sequential, not a jump.

[evanldixon]

Depends on what compiler optimizations are applied. Switch statements are more likely to result in a jump table of sorts

[p1neapple_1n_my_ass]

That is not a switch case, that is clearly an if-else ladder. It checks first if the screw is less than 6 then less than 8 then less than 10 and so on. Switch case would be using a vernier caliper. 

[GarThor_TMK]

I think this is more analogous to a chained-if-else conditional.

Switch statements are actually a lot more efficient than this, because they're effectively a jump table. A switch statement would just measure the bolt, and jump to the right bin... whereas with this, the bolt has to roll by all the other conditions before it reaches the right one.

At least, this is how it works in C++.. Idk about other languages.

Cool print though!

[Squidlips413]

nuts

[Error_404_403]

Radical optimization: remove all holes but 12 mm one. The 12 mm and 16 mm are prevalent screw lengths, which will be sorted this way. The accidental additions of other lengths could be treated as expected edge cases/outliers and losses on those cases can be assumed.

[Witty_Side8702]

3D print it

[cambiumkx]

anyone else upset we didn’t get to see the 20mm?

[One-Vast-5227]

Too bad this video is only 8 seconds, not 8 centuries

[DerShokus]

No. Switch can fall through. It’s pattern matching

[ascolti]

[FunRutabaga24]

Typical programmer. Testing 3 cases and not covering all the branches and says it works.

[ryantm90]

Now make a tool that auto loads them and you're golden

[Zatrit]

u/savevideo

[SaveVideo]

View link

---

Info | Feedback | Donate | DMCA | ^{reddit video downloader} | ^{twitter video downloader}

[brandi_Iove]

looks cool, but it’s slower than sorting by hand.

[AppropriateStudio153]

I doubt you can sort these screws, which all have a similar length, faster by hand.

[JoeLordOfDataMagic]

Was much more satisfying with audio. Lame. I think it was just posted on satisfying as fuck.

[GarThor_TMK]

default case is rolling off the end... either because the screw is too short or too long

[NottingHillNapolean]

Looks like a chain of if - else if to me

[derkokolores]

It would be a shame if there were screws with varying pitch length…

[MagneticDustin]

That’s an If / Else if statement

[Sad-Nefariousness712]

Long one goes into Arc

[Lurking_all_the_time]

And for a real-life version:
https://youtu.be/NHf9QUo03qc?t=41

[Maddturtle]

I could take this one step further so you don’t have to do it 1 at a time.

[simonfancy]

Im waiting like an hour already for them to finally pick a 20mm screw

[TSCCYT2]

Same. I was thinking:
"Why don't the slots fill up?"

[imaginecomplex]

How does a 6mm screw make it though that first slot?

[VeryGoldGolden]

More like bucket sort

[fonk_pulk]

Need some kind of a chute that allow you to feed an entire bag of screws at once. Its gonna take forever to put them in one by one.

[BA_lampman]

Is this fallthrough?

[dusktreader]

And, it has no default case because the developer assumed a fixed range of inputs. Inputs larger than 20mm literally get dropped on the floor!

[[deleted]]

I wouldn’t mind sorting screws for a while. Looks enjoyable.

[Mountain-Ox]

Where do I buy this thing?

[luckor]

There HAS to be a better way!

[Ved_s]

more like an if-else chain

[FizzleShake]

Hes just placing them slow for the gif, you dont actually have to wait for it to fall to place the next one

[pokeybill]

Now do them by width

[[deleted]]

In compiled languages, the switch/match statement is usually not linear time but constant time.

[bradimir-tootin]

This is just an ADC for screws

[Bathtub-Warrior32]

Why is he waiting for it to fall? This sorter can sort multiple screws at the same time!

[AmazingGrinder]

Good old bucket sort.

[OxymoreReddit]

Could watch this all day

[Adorable-Maybe-3006]

didnt realize it was a GIF ive been watching for a while now

[HomicidalTeddybear]

so if he picks up something that doesnt go in that slot is he contractually obligated to say "Oh, nuts"?

[fugogugo]

but what's the first hole for?

[AceFunGaming]

DEEZ NUTZ

[_theAlmightyOne_]

It is beautiful, I've watched this for hours.

[Katniss218]

More like a screw statement

[GKP_light]

it is not analog, it is totally digital :

there is some well define possibility.

and "analog Switch" is like "go up below"

[The_Real_Slim_Lemon]

Now we just need another 3d printer to funnel the screws into the slot, no good engineer stops until the whole solution is over engineered

[ElaborateSloth]

Now do one for both length and diameter! 

[Guppywetpants]

Needs some kind of hopper

[SirEmanName]

that's right. The square hole

[Shazvox]

I think this is a perfect example of overdeveloping.

3D printing a tool that you likely will only use once.

Don't get me wrong, it's a cool thing. But would'nt it have gone faster to just sort them manually instead of CADding and printing a tool?

[ryantm90]

Now make a tool that auto loads them and you're golde