Swift Algorithms

https://swift.org/blog/swift-algorithms/

by Austin_Conlon • 6 years ago

270 72 6 years ago

Kednicma• 6 years ago

Worse nomenclature than any other big language I can think of, including Go and Python. Why should this package be called "algorithms"?

iainmerrick• 6 years ago

C++ has similar nomenclature - - the std::algorithms library has generic functions for working with collections: https://en.cppreference.com/w/cpp/algorithm

Whether C++ is a good model to follow is another question entirely, of course! But at least Swift isn’t being completely idiosyncratic in its naming choices.

coldtea2• 6 years ago

Huh? It sounds like it shouldn't be called anything BUT algorithms. It implements standard generic algorithms for various operations. The kinds you'd be asked about in an algorithmic test, learn in algorithms 101, and so on.

Of course technically any part of a program is an algorithm, but usually (like here) we reserve the name for general things like here (from path and graph to partition and search algorithms), not for our "business logic" algorithm.

summerlight• 6 years ago

These functions are designed to be highly generic so can be used as building blocks for many other more specific algorithms while it is not specifically tied to other concepts like container or iterator. Do you have any concise alternatives that reflect these properties?

happytoexplain• 6 years ago

a new open-source package of sequence and collection algorithms, along with their related types.

This is exactly what algorithms are at the level of almost any language's included libraries. The name seems spot on.

jerome-jh• 6 years ago

I agree this is a poor use of namespace. Python has that in itertools, Numpy has combinatorics and random sampling in numpy.random. Maybe they just planned to stop here? Or the algorithm namespace is bound to become overcrowded.

coldtea2• 6 years ago

One issue with Go's lack of generics is exactly that it can't have such a package (and have it be type safe, fast, and work across all relevant types), except with repeated code.

pmiller2• 6 years ago

Sounds to me like a job for a DSL that compiles down to Golang for the final output. That way, the repeated code only exists in the Golang output and not in the code that humans actually write.

setr• 6 years ago

the solution is... to not use Golang!

more specifically, fairly basic operations on a list of data does not seem like it should call for the complexity of a DSL. IMO unless you need to do this quite a bit on random datatypes, copy & paste would probably be the better alternative. Unless you're referring to a DSL that looks exactly like Golang but with generics & monomorphism.... in which case ok I guess

mhh__2• 6 years ago

If you do that you have no soul. Why complicate it when you can just have generics that work from the get go

bee_rider2• 6 years ago

Googling about this (I assumed the actual 'solution' would be a to use C-style awful macro kludges) eventually lead me to:

https://blog.golang.org/generate

Now I'm wondering if you joke was not actually a joke.

vips7L2• 6 years ago

Instead of just using an actual good language?! Go is the problem!

spullara• 6 years ago

Ah the original templates from C++.

dmitriid• 6 years ago

Sounds to me like a job for a DSL that compiles down to Golang for the final output.

So, you mean it's the job for generics. Which is a DSL for, well, generic types that compiles to final output. That way, the repeated code doesn't even exist, especially not in the code that humans actually write.

benhoyt• 6 years ago

Yeah, though a solution is in the works, and looking pretty likely to happen. Here's the official draft design for generics or "type parameters" in Go: https://go.googlesource.com/proposal/+/refs/heads/master/des...

wlib• 6 years ago

Dependently typed Golang when??

In all seriousness, it feels like go's reputation of simplicity is at odds with its design. Instead of making a simple and highly generalized core from which anything can be composed, it has a specialized, familiar core that engineers are comfortable with.

When I take this question further, I begin to wonder why we even use text syntax for programming. What if we just had a graph structured programming "language" that is edited indirectly through different projected syntaxes that aren't necessarily monospaced text. Almost like lisp, but translated into different frontend languages, potentially graphical. (Maybe off topic but whatever)

elpakal• 6 years ago

I love this, and best of luck to Nate and the Apple team. I wonder how many of the (awesome) algorithms on Ray Wenderlich's similar repo fit in: https://github.com/raywenderlich/swift-algorithm-club

rudedogg2• 6 years ago

This looks great. I'm looking forward to this and swift-numerics maturing.

If you haven't seen it, check out the 2018 WWDC session "Embracing Algorithms" (https://developer.apple.com/videos/play/wwdc2018/223/). It's worth watching, even if you don't work with Swift.

zapnuk2• 6 years ago

I second that. So far every talk by Dave Abrahams has been entertaining and insightful to me.

Austin_Conlon2• 6 years ago

He was also recently interviewed on a podcast here: https://swiftbysundell.com/podcast/71/.

the_dripper2• 6 years ago

I'm watching the talk now, the way the speaker describes the things he does seems to me like hes making fun of the Silicon Valley type lifestyle. I think the talk is really great and funny, thank you for sharing !

Austin_Conlon2• 6 years ago

He's satirizing the rigid and dismissive Gilfoyle type of person (HBO Silicon Valley character) while also exploring what app developers can learn from them.

typon• 6 years ago

Is Swift worth learning if you're not going to be doing Apple development?

rudedogg2• 6 years ago

I've been using Swift for over 5 years now I think.. and I would say no. Outside of the Apple ecosystem the only thing that is really of interest right now is Vapor.

It's a nice language though. I worry it's getting too complex, but the new features enable SwiftUI to work so I can't complain too much.

xenihn2• 6 years ago

No IMO, but Apple (iOS, macOS not so much) development is still an incredibly lucrative niche, and will continue to be so until the United States collapses. It might even still be useful after that.

austinl• 6 years ago

As an iOS engineer, I'm a bit biased, but I'd still say it's currently not practical to learn it if you're not doing Apple development.

That said, I love the language, and it's a big part of what motivates me to continue being an iOS engineer (I'm not sure I'd still be at if we had kept on with Objective-C).

I would love to see server-side Swift take off, but the ecosystem is still fairly new, so any large project would require you to roll your own solutions more often that you would need to in other languages. I was also excited to see https://www.tensorflow.org/swift — Swift being used for ML. Swift is working on support for differential programming, which is a cool development in the space. More info here: https://github.com/apple/swift/blob/main/docs/Differentiable...

Perhaps eventually there will be enough applications outside of the Apple ecosystem to reach a critical mass.

moksly• 6 years ago

As a developer in non-tech enterprise, my biggest dream is probably swift being capable of targeting web and android.

We don’t have the resources to currently target all three platforms, and we don’t have much hope for google frameworks as they tend to be changed/abandoned faster than we can afford to adopt them, and we can’t really rely on Facebook tech too much because of corporate ethics (I know it don’t make much sense, but it’s non-tech enterprise, this is probably the least weird ethics rule).

I mean, it doesn’t really have to be swift, it could be python, .net or kotlin, for all I care, but it’s probably more likely to be swift.

bee_rider2• 6 years ago

That github differentiable programming link was an interesting read. It reminded me of interval arithmetic in the same sort of "But wait, why can't we just jam math into this program" vibe. Very neat.

madeofpalk• 6 years ago

I can't really see a reason to use Swift if you're not targeting Apple platforms.

I think between Nodejs, Python, Go, (and maybe Rust), I can't really see much of a compelling usecase for Swift on the server. Even if you're developing a server component for an iOS app, I don't think it really is all that common to share a core between the two.

pjmlp9• 6 years ago

Only if you are a language geek, and want to open you mind that C and C++ aren't the only game in town for systems programming.

Other than that, outside Apple platforms is still in a worse state than clang Objective-C + GNUStep.

xixixao• 6 years ago

Nice! Similar space to https://github.com/xixixao/jfl, might steal a couple (rotation is a good one)

xenihn2• 6 years ago

I'm really, really happy to see this. I know this is going to sound like parody or satire, but I swear I'm being sincere: this is a huge deal for applying to FAANG (and companies that do FAANG interviews) and leetcoding in Swift.

It's incredibly painful and off-putting to re-implement stuff you get for free in Python and Java when you're trying to learn everything else at the same time. Some companies give you the option to use whatever you want if you're applying for an iOS position (Google), and some don't (Apple, Facebook). But either way, if you do iOS, odds are you spend 99% of your time at work writing Swift and/or Objective-C, which means you'll have to put in extra effort in learning/re-learning Python or Java.

This is especially great for string algorithm problems. Manipulating strings in Swift in an interview is a traumatic experience if you haven't drilled it repeatedly, and you rarely need to do it during Real Work if you have functional backend developers.

Dhar_mendra• 6 years ago

Article is very nice

mikkelam• 6 years ago

I would love to go and use swift at my work (working in robotics). But swift just doesn't feel mature enough for barely anything outside of iOS/macOS. I had a great time using it for that purpose. The community outside of that ecosystem is barely there.

I've picked rust instead, it feels like the exact opposite of the single large actor supporting swift, instead it's a huge community effort with lots of use cases already being seen in many spaces. AND rust just got AVR support which I suppose swift could get pretty quickly with llvm as well

Cthulhu_2• 6 years ago

Yeah, back when we first started using it there was a lot of interest in using it to create back-ends as well, but there just wasn't a lot of support for it. For one, it needed to be developed and compiled on a not-Mac environment to be viable, and that has just never been much of a thing. Might be better now, it does just use LLVM in the back-end and IntelliJ has a good editor for it, but still.

I think C# had that problem for a long time, but Microsoft did a great job / made a great strategic decision with .NET Core I think.

dep_b• 6 years ago

Still Mono, Xamarin and Unity preceded that decision.

Someone• 6 years ago

“rust just got AVR support which I suppose swift could get pretty quickly with llvm as well”

In theory, yes, but in practice I don’t see Swift going there comfortably. Its more dynamic runtime (compared to C or rust) needs more metadata, eating memory, which is precious on AVR (384 kilobytes, max, reading https://en.wikipedia.org/wiki/AVR_microcontrollers)

pjmlp9• 6 years ago

Just like you don't do ANSI C there, so a similar constrained version might be possible, not much different from Pascal.

https://www.mikroe.com/mikropascal-avr

hechang1997• 6 years ago

I saw posts on r/rust talking about making a rust-like language for non system programming. I think Swift fits exactly that purpose, only frustrated by Apple giving it Windows support a decade after it's creation.

objclxt• 6 years ago

only frustrated by Apple giving it Windows support a decade after it's creation.

Swift was only publicly announced six years ago.

zapnuk2• 6 years ago

Looks great. But I wonder why there are platform requirements for what seems to me like pretty basic functions.

In RandomSample.swift:

  // For log(_:) and exp(_:)
  #if canImport(Glibc)
  @_implementationOnly
  import Glibc
  #elseif canImport(Darwin)
  @_implementationOnly
  import Darwin
  #endif

1. Why aren't those 'basic' functions already implemented in swift, and part of a math package (or in numerics)?

2. Why release a package that does not support windows now that windows is officially supported?

stephencanon• 6 years ago

They _are_ in Numerics (including Windows support). I think Nate is just trying to keep dependencies to a minimum, but feel free to raise an issue.

pjmlp9• 6 years ago

Swift blog also has enough of such examples right on the introduction.

bredren• 6 years ago

How much of this collection had decent open source packages already available?

How much more efficient are Apple’s algorithms over what was generally accepted as the best prior open source version?

Were these algos already a standard set for Apple engineers internally?

It seems like customers win if Swift apps are more efficient and less error prone.

random3479236• 6 years ago

I don't understand the hype honestly. Every modern high level language should provide these algorithms. I tried Swift and it has some nice features, but i in my opinion it's not suited for system programming, because it has some very religious design desicions. For example:

- You can't use a for loop to loop over array elements by reference.

- Just look how to work with pointers in swift. There is nothing more to say about it. https://www.raywenderlich.com/7181017-unsafe-swift-using-poi...

A system programming language is a language in which you can write an memory allocator, or a function like dlopen(). While you can possibly do this in Swift, it would be much easier even in C.

I don't want to say swift is bad. The design desicions are ok for an application programming language.

Swift Algorithms

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