Go is an example of how to be extremely successful by catering to the needs of the project's core audience (well-rounded stdlib, extremely fast GC, short build times, trivial deployment, etc) while paying much less attention to the vocal minority's complaints (generics, package system, etc).
But I think there is more to it. I have used Go (almost) exclusively for private toy programs I write in my free time to relax (sounds weird, I know), so my perspective may be warped. But something about is very compatible with the way my mind works. With some other languages, say C or C#, I find myself constantly browsing through documentation to figure out what a given construct means in that language. And don't get me wrong, I like both of these languages.
But with Go, my intuition what I think a given piece of code should mean is nearly always in line with the language specification. The only other language I had this level of rapport with is Python.
There are many things I miss in Go, but all in all, I think it is simplicity done right.
BUT if Go had not also gotten the things right that you mention, it probably would not have become this popular.
> my intuition what I think a given piece of code should mean is nearly always in line with the language specification.
for some things yes, but for others I think that it's more familiarity than intuition, take for example interface slices, you start by learning that you can assign any type to interface{}, so intuitively you'd think that you could assign any type slice to []interface{} but you find out soon enough that doesn't work
If you dig a bit it is completely understandable why it doesn't given how interfaces are laid out in memory, but from an intuitive standpoint you'd think that since you can do it in the scalar case you should be able to do it in the slice case too...
This is a very minor nitpick, I do agree that compared to many other languages golang is very easy to mentally parse, at the expense of some expressivity at times.
Whenever I code in it, which these days is pretty much all the time, I do miss some conveniences from other languages (generics, list comprehensions, ...) but of course every language has its tradeoffs, I most certainly miss golang's strengths every time I have to write some C or python.
IMO interfaces are the Achilles' heel of Golang. Another thing that has been bugging me about them is that you cannot specify which interface you're implementing in the code (beside from comments). I think that is so because Go hates circular imports. If you had to import a file to be able to use an interface, you'd soon run into compile errors due to circular dependencies.
And as there is no way to immediately see where some interface is declared and if/which interface is implemented, you have to rely on comments and resort to manual search to find out more. That may be easy in smaller codebases or worthy of effort in important codebases such as Go standard library. But all an all this ambiguity does not fit with Go's discipline to prevent human errors by making everything uniform and explicit as possible.
Just for the sake of providing an example, let's look at time.go under https://golang.org/src/time/time.go, we can see in the comments of several functions that the programmer states a particular interface is implemented. Line 1112 of the aforementioned file is as follows:
Now where is encoding.BinaryMarshaler declared? There is a package called encoding, maybe there? But the package has many many files, where would I find where BinaryMarshaler is defined? I'd have to resort to manual search. Now imagine that this is not an interface in the standard library, but rather an interface in some mediocre codebase that you're handed for the first time...
Tl;dr All I'm saying is that runtime errors due to empty interfaces are not the only flaw of Golang. Interfaces as implemented in Go could in some cases present a serious threat to code structure.
I actually experienced the opposite. Interfaces in go work so well, partly because you can create an interface which automatically gets satisfied by existing structures. For example I often use a requestDoer interface which only has the http clients "Do" method.
I'm using Goland so I have jump to interface from any structure implementing it. So that's another one that gets solved by tooling.
The structurally typed interfaces are actually my favorite part about Go probably.
How do you jump to the interface from any structure implementing it? Beside from comments there is no immediate way to which interface/interfaces a structure is implementing.
Maybe Gogland solves this by keeping records on all interfaces, and checking all structures whether they satisfy them. If that's the case, this is definitely solved by tooling.
If you need this, you can write type assertion lines in a var block of the interfaces that you explicitly want to implement (and this will throw compile time errors if they don't).
The standard godoc documentation browser does this too when started with the -analysis option. They all use the same source code oracle functionality available from the x/tools repo.
Thanks for the correction. I think that's somewhat unfortunate, though. The powerful shared tooling is one of the strengths of the Go ecosystem and if there are issues with it that prevent the use in Goland I'd rather see those get fixed.
OTOH, they (Jetbrains) probably have shared infrastructure (between languages) within their IDE code base, too, and are more comfortable using their existing tooling.
EDIT: I can also search for any interface with a struct selected, and generated stubs for all method. Well, basically what you get for any other language when implementing interfaces.
It would be nice to add at least the options to explicitly state that type X should implement interface I, and have the compiler barf / emit an error if X does not implement Y.
Like I said before, this has not been enough of a problem to really bother me, but I would be quite happy if Go fixed this.
Yes you could, but then you'd have to have both the declaration and the implementation of the interface in the same package. That would mean that if either of them is in a separate file, you'd have to import it. That in return, could easily call hellish compiler errors due to circular dependencies. In Go any circular dependency is an immediate compile error.
Looking at the link, the second advice is that you could require users to implement special functions such as ImplementsFooer() to explicitly declare which interface they're implementing. This could help, but this practice is not present in the codebases I've seen including the Go standard library (to the best of my knowledge).
That's a clever way to solve the issue. I think most Go codebases could benefit from such explicit checks where the language does not provide an unambiguous solution.
The interface issue has been on my mind for quite sometime. I had thought maybe declaring all interfaces in seperate files might help with the structure (like having the definitions in a header file in C), but the Go standard library does not use this approach. Interfaces and implementations are scattered across files and modules. Maybe I'm being too clever and we all know that Rob Pike always says that programmers should not be too clever. Maybe I should loosen up a bit, and treat Golang more like a pragmatic language. They did the best they could and produced a wonderful language. Any additional feature such as generics and explicit implements statements would have made the language much more complex.
All the go files in a directory have to declare the same package name (`package mypkg`), with one exception: a test file (filename ends with `_test.go`) that has a package name that's the same as the normal package but ends with `_test` (as in `package mypkg_test`) is allowed to be in the same directory.
These are actually completely separate packages and you have to import the main package if you want to actually use it. But when you run `go test` it automatically complies and runs tests in both packages. This means that you can import both your package and a dependent package to make sure interfaces are satisfied without any circular dependencies.
Sibling comment shows one way to do it, but in most cases, at least for me, which is when both the struct and interface are in the same package it gets solved by the NewMyInterface method.
As it's return type is MyInterface, but it actually returns myStructure which causes the compiler to check the interface satisfying.
> I think that is so because Go hates circular imports.
Well it could be but I don't think so --- "duck typing" when it comes to interface{}s has been a goal from early on, quite simply. The very idea of interfaces as "a set of func signatures" preclude the necessity to verbosely spell out "struct Foo implements BinaryMarshaler" and/or "func (_ Foo) MarshalBinary implements BinaryMarshaler.MarshalBinary"!
In the same vain, you don't even need to declare interface TYPES, you can accept/pass/return "inlined" interface{MethodSig(argtype)rettype} anywhere if you want. Not the most ergonomic choice in practice, but the possibility hints at this underlying interfaces-are-duck-typed-method-sets paradigm at work here.
> take for example interface slices, you start by learning that you can assign any type to interface{}, so intuitively you'd think that you could assign any type slice to []interface{} but you find out soon enough that doesn't work
Why do you expect this to be the case? Just because you can assign a char to an int in C, you wouldn't expect to be able to assign a char pointer to an int pointer. Similar for C++ and std::vector<char> vs std::vector<int>.
It's the same and probably even more relevant with void∗/int∗ (assignable) vs. void∗∗/int∗∗ (not assignable). You can assign an int∗∗ to a void∗, though, just as you can assign an []int to an interface{} in Go.
Also, even as an absolute greenfield programmer with no experience in other system languages, if you really think it through, you will come to the conclusion that it mustn't be possible to assign arbitrary slice values to an []interface{} variable, given the way slices work.
> intuitively you'd think that you could assign any type slice to []interface{} but you find out soon enough that doesn't work
I've been writing Go for upwards of six years, professionally for three, and I have never tried that. I can't think of the last time I used interface{}...
I generally consider anything using interface{} crap code someone who doesn't know the language wrote, probably coming from a loosely typed language.
> I generally consider anything using interface{} crap code someone who doesn't know the language wrote, probably coming from a loosely typed language.
Disagree. There's ample usage of interface{} that you need to type-switch on in parts of the stdlib that deal with the AST and reflection or various other areas. You might also UnmarshalJSON a structure where some field can contain any one of a number of possible sub-structures. Once we're talking about 1-2 dozens of possible sub-structures, you'll have that field be an interface{} and type-switch on it --- rather than having 1-2 dozen pointer fields that will all-but-1 be nil and having to if-else through them all.
Go does have brilliant simplicity! It's the simplicity of Pascal I used in middle school, and of Modula-2 I used on my freshman year, with basically the same syntax. I'm glad Go revived a number of good ideas from Pascal / Modula / Oberon.
For writing toy programs to relax (can relate), I personally prefer Python, or maybe a Scheme. While also being simple at the core concepts, they have much more expressive power, an easier way to combine simple things into complex things. They pay for that by higher resource consumption, of course. I do fondly remember a PDP-11 Pascal compiler reporting "15 KB used" after compiling my program; you can't get a Python process with these constraints. But by now we have _vastly_ more computing power.
Go has human-sized simplicity. Programming language complexity is limited by human cognitive limitations, and Go has a small cognitive load.
This makes it feel like a very intuitive language.
That doesn't mean it is an intuitive language - just that it feels like one for a specific class of problems.
Personally I enjoy using it for the same reasons as everyone else. But... I'm also aware it's quite an old-fashioned language, with some bumps under the floorboards where useful things were hammered down to make them go away, instead of being fully solved.
> I write in my free time to relax (sounds weird, I know)
Not weird at all. I do that myself. I believe the relaxation is in pure creativity, the wonder of exploring something novel and the absence of any pressure or stress due to timelines or deadlines. You're also exercising both right and left sides of the brain.
I suspect there are many many more who do the same.
Huh. That are exactly the reasons I would give if I had to explain that hobby to somebody. ;-)
Feels kind of good to know that I am not the only one doing this.
When it goes really well, programming is akin to what I think meditation must be like. But explaining that to people who have never programmed themselves is hard.
> But something about is very compatible with the way my mind works.
Yes. For me it is channels. After nearly 20 years of UNIX'ish systems, pipes are a mental abstraction that I do not have to think about any more. And channels fit right in, they feel much closer to a how a pipe is used on the cli than a pipe or socketpair ever did in code.
For example a range loop over a closed channel is, for me, piping things to xargs. It's easy to understand, reason and conceptualize because it feels familiar.
I know other people meet a similar purose by knitting or solving crossword puzzles, but explaining to them the trancendetal nature of their favorite pastime is quite difficult.
(I'm not sure if GitHub sorting is broken, but the same issue has more +1s than the top +1d issue as per that sort mode as well)
Generics has the most experience reports in Go 2 proposal. Maybe this can be categorized and excluded as a vocal minority, but above data doesn't seem to.
I'm afraid not all votes are (and should be) considered equal by the project maintainers. A great number of casual Go users might want feature XYZ. OTOH a couple dozen of large Go projects, with combined millions MLOCs and hundreds of millions of end users, may have a different list of priorities, and these priorities might be catered first.
Also, let's not forget that Go is created at Google, and definitely Google's internal projects, likely large-scale by both line count and users served metrics, must take priority.
Frankly, there is a number of reasonably nice languages that do provide generics, good / great type systems, good / great package management, decent async features, and quite decent performance: Rust, Nim, Crystal, ... all the way down to Haskell. Go is not competing with them at their strongest features. Instead, it's in the sweet spot of simplicity, fast build times, reasonable hygiene, and trivial deployment. It's the "getting job done" mentality which worked so well for PHP and Perl back in the day. There is a considerable demand for that.
>I'm afraid not all votes are (and should be) considered equal by the project maintainers. A great number of casual Go users might want feature XYZ. OTOH a couple dozen of large Go projects, with combined millions MLOCs and hundreds of millions of end users, may have a different list of priorities, and these priorities might be catered first.
Many large users writing in company and project blogs have mentioned lack of Generics as a pain point, so that distinction doesn't go very far.
>Also, let's not forget that Go is created at Google, and definitely Google's internal projects, likely large-scale by both line count and users served metrics, must take priority.
Go was not created through some official decree to create a Google language, nor was it mandated to be used or to have some timeline to convert other stuff to it, etc.
It's just a project started by some Go people with the idea "let's examine what a language appropriate for Google's programming would be" -- but using their personal ideas of what Google style programming would need, not something requested, researched etc by Google as an organization. In other words it started as a glorified 20% project, and today it's not any more official in Google than C++ or Java is.
I suspect that Rob Pike's and Russ Cox's work is paid for by Google.
But even if it were not, I suspect that heavyweight users like Google do have a weighty say, just because of the sheer amount of practical experience they have with developing and running software using the language. Just like Mozilla, I suppose, do have a say in the development of Rust.
We’ve actually worked a lot to ensure that Mozilla can’t dictate what happens with Rust; we run a consensus based process, and while Mozilla has the largest single group of people involved in leadership, it’s still a very stark minority.
As a huge production user, Mozilla’s needs are still important to us, but we think of Rust as an open source project Mozilla contributes to, not a Mozilla project per se.
I wonder if this is good or bad. Sometimes it helps to have that singular vision. I think here of all the systems C coders I know, who have never used complex numbers, yet that finds its way into the standard.
As a Rust user outside of Mozilla, it's very good. Rust would have had a hacked-on OO system solely in order to implement the DOM in Servo if browser engine hackers were the only ones with a voice. :P
It's fair to be concerned at the potential evolution of a language that doesn't have a BDFL (I myself came to Rust from Python, after all), but in practice I've come to trust the Rust devs as having very good taste (objective, I know!) and a strong resistance to maximalism (regardless of what some may claim... the list of features removed from the language is longer than the list of features that it has!).
I think in general, the teams, and especially the core team, have a "singular vision" in the big-picture case; this helps. It really can go any way though, I've also seen BDFL projects where the D doesn't care about what the community wants, which ends up with that complex number problem too.
>I suspect that Rob Pike's and Russ Cox's work is paid for by Google.
They are. The distinction I'm trying to make is they have not been tasked to "create an official Google language for Google scale projects", nor what the language officially adopted as "THE" google language the way e.g. Kotlin was officially adopted as a language for Android programming.
Some googlers (Pike and Cox among them) sat and designed a language that they thought would be good for Google scale programming (according to their ideas and experience) and they went and implemented it. Google paid their salaries the whole time, but at least at first, not for the purpose of creating such a language. After the language is out it paid, and even added more people, to keep it going --it gives good PR, and can be used internally here and there, so that's worth it to them.
It's just not "the Google language" in the way Obj-C/Swift are the Apple languages and C#/VC++ is the MS one (the company heavily investing in them, explicitly asking them to be built, suggesting their use everywhere, etc. For Google it's more of a side project than what e.g. Lars Bak worked on.
It's the biggest issue, but that doesn't mean the majority of Go developers support it. 1734 people reacted to the generics issue, most in favor, but there are many more Go developers than that.
But the people who read the proposal and reacted to it may be the vocal minority who are concerned about generics. The majority may not spend their time reading or reacting to proposals they don't care about.
>Also, let's not forget that Go is created at Google, and definitely Google's internal projects, likely large-scale by both line count and users served metrics, must take priority.
And many more want Generics without having responded to the issue.
Issues are representative as a sampling, not absolute numbers.
Unless you do random sampling, you still can't conclude anything one way or the other about whether it's a majority of users. Perhaps something like Google Surveys could be used to settle this?
> Issues are representative as a sampling, not absolute numbers.
My point was that issues are not a reliable sample of the Go community as a whole. They're a self-selected population of Go developers who cared enough about generics to click on a Github proposal on the subject and react to it. I'll say it again:
>> The majority may not spend their time reading or reacting to proposals they don't care about.
Maybe the majority do want generics, but the Github issue is poor evidence. A random sample of Go developers would be much better, and then we wouldn't have to make up things like "And many more want Generics without having responded to the issue."
I accidentally re-pasted the same quote from nine_k I've answered to higher up the thread.
Meant to quote this from you: "1734 people reacted to the generics issue, most in favor, but there are many more Go developers than that".
>*
My point was that issues are not a reliable sample of the Go community as a whole. They're a self-selected population of Go developers who cared enough about generics to click on a Github proposal on the subject and react to it.*
And my point is that I don't think this is the case. I don't know either way, but there's no reason to assume people caring to vote in the issue are necessarily not representative -- like I don't think that for any other project/issue combo on github.
In any case, even if they aren't representative of existing heavy Golang users, who cares about them? The language is still niche. There are tons more programmers to come to the language than those that already are using already.
So I would very much pay attention to what those not yet using it but caring enough to vote have to say about it.
Speaking as someone who worked fulltime with C# when it was relatively simple in v1/1.1 which was before generics, and Object Pascal/Delphi for many years before then - when generics arrived in C# 2 it was a truly wonderful upgrade.
However the complexity of C# has exploded over the years, and it now lacks in simplicity, where Go shines. Yet I expect adding generics would improve Go as it certainly improved C#.
However the trick is knowing when to stop adding features, and with with the incredible pace of churn in most languages these days, it's a major competitive advantage to just not change the language. And advantage that would complement the simplicity of Go nicely.
(Of course it's theoretically possible for users to not upgrade as the language upgrades, but the reality is when the language changes it fragments the documentation, user base, and overall experience - so the argument for users not to upgrade, is not realistic.)
In chess there is the concept of a zugzwang, a situation where it's actually a dis-advantage to make a move. There's lots of other kitchen sink languages these days, Go may be best to keep building on the strength of it's simplicity, by simply not changing.
And then there are many Go users, who don't really care for generics, or like me, think generics could be nice, but could also make the language more complex than desirable.
If someone came up with a practical, clean, working proposal for Go - then absolutely. But so far I've only seen complaints and proposals where the conclusion starts with "this proposal will not be adopted" - mostly because it's somehow flawed.
It is a vocal minority in the (probably correct) assumption that the majority of Go programmers are not part of that GitHub issue, nor any other group asking for Generics.
It should be obvious to folks on HN why a Github issue that may go completely unseen by a large swath of the go community, or +1's which can be gamed/trolled, should not be taken as a valid measure.
What the developers want is for people to submit _actual_ problems that generics would solve, with examples. Because there are more than a few way to do it and they want to pick the right one.
That's easy. Concurrent access to maps is unsafe. https://golang.org/pkg/sync/#Map should be a drop-in replacement but due to the lack of generics it can't present a compatible or typesafe API.
I've run into concurrency problems using maps while writing an irc client. It was really frustrating for me, because it did not happen everytime I ran the program, but rather rarely. I had chosen Go for it's memory-safety and easy concurrency. But I felt like I could not vouch for my program's safety any more. I did not know about sync/map at the time, had I known, I would probably have used it.
I think Golang has a fondness for magical (to me) special language constructs. For example if you want to use the RPC modules, you have to write your functions a certain way. Or as I've explained in a comment above, if you want to use an interface you just have to implement all it's properties. Or you can't have generics, but we have a special language construct called maps, where you kind of can mimick genericks but it is not safe and may break.
Golang is a great language, but I think it expects all its users to think very rigidly in the same way their designers do. Basically, you have to explore the language's deficiencies yourself, read the designers' explanations, dive into the intrinsics of the language, understand it, make yourself believe and move on. I sometimes half-jokingly feel like Golang follows the principle of most obedience.
I discovered Waitgroups during the project, but I have no formal training in concurrent programming, so it was a bit daunting for me. And as the error occured very rarely I could not be sure if using a mutex had solved my problem. But now I understand mutex was the way to go for accessing a shared resource.
As for the second point, sorry for the wrong wording, I meant "methods". But interfaces don't work like that everywhere they exist. For example in Java you explicitly use Class X implements Y, and if you do not implement all methods and properties, the compiler complains.
Don't know about your exact map use-case you had at hand, but generally speaking the Mutexes suffice for Lock()ing/Unlock()ing a resource that is accessed concurrently, whereas the WaitGroups serve usually best to just fire off a couple of parallel jobs (that don't access any shared-between-them resources) and then simply Wait() for them all to finish. No real protection from concurrent accesses in there, other than for the WaitGroup's own hidden internal counter that's used to Wait()
Of course these are the low-level sync primitives, channels are the higher-level abstraction, but the former can take you far --- sometimes the latter are the sanest/only choice of course. Especially for parallel goroutines needing to work with each other's intermediate results.
Java interfaces don't have properties either (nor do Java classes), and you can explicitly state interface conformance in Go as well as others have explained elsewhere in this debate: https://news.ycombinator.com/item?id=15672619
What Java does have (since 8) is default method implementations in interfaces.
Sorry, my fault. It seems in java you can declare constants in interfaces, but this is frowned upon.
Interfaces cannot require instance variables to be defined -- only methods.
(Variables can be defined in interfaces, but they do not behave as might be expected: they are treated as final static.)
go, a language which comes with many built in concurrency primitives, has chosen to leave its core datatypes thread unsafe (the magic ones with generic powers) and gives no sensible tools to remedy this with. this is one of the many ways in which it is a language hostile to its users.
Often, you don’t need concurrent types and their overhead. The sync package makes it easy to bolt on if you truly do.
It’s not as if every block is sending out each line to run in a separate goroutine. Go encourages users to share data by communicating, not communicating by sharing data [0].
On phone, sorry for syntax
struct CMap {
sync.RWMutex
i int
}
func (m *CMap) Inc() {
m.RWLock()
defer m.Unlock()
m.i++
}
i understand the patterns and design intentions of the language, despite not having written very much of it. (i just checked my work stats and i'm surprised to find that i've written/changed nearly 40k lines of go - of course that counts for less given how verbose the language is). one of my complaints is that a language designed to be simple has made (to me) incomprehensible design choices in the name of efficiency.
for instance, in a for loop ranging over a slice:
for _, i := range some_slice {
go func() {
something(i)
}()
}
i is re-used for every iteration of the loop, so the asynchronous function does not close over i as a particular value, but rather i as whatever value the loop has iterated to by the time it is referenced. i see experienced go programmers make this mistake sometimes, even when they've run into it before. my take is that the golang designers chose to implement this behaviour to either simplify their work or in the name of efficiency. if it's the former, it's indefensible. if it's the latter, why not offer user-friendly semantics (let closing over i as in the example capture the iterated value) and simplify the generated code at compile time when possible?
for your example, you can look to the newly added sync/map which uses interface{} everywhere as an example of how the lack of generics have left users with no _sensible_ tools to remedy these kinds of language problems. how wonderful would an efficient thread-safe and type-safe concurrent map be? it's possible in many other modern and not so modern programming languages, but it is intentionally not possible in go.
for (int i : someCollection) {
pool.execute(() -> something(i));
}
Because "i" is effectively final, each Runnable closes over the correct value for that iteration. If "i" were being reassigned, the closure wouldn't be allowed to use it, you'd have to decide whether to close over a final copy or a reference to a mutable object that holds the latest value over time (a one-element array is the idiom).
However a common situation is that the language is supporting a wide range of uses, not just the use a particular developer has in mind at the time.
I've seen this most commonly where a developer operating at a higher level of abstraction, without understanding low level details, complains that the language doesn't match his high level needs exactly.
When in fact it supports lower level operations for maximum performance or flexibility, while allowing layering on top for higher level uses. In language design it's essential to support the lowest level use cases you are targeting, because you can build on top but not go lower than the language exposes (unless it supports embedded asm or another trick to go lower again). I'm using higher/lower here only to refer in the sense of the level of abstraction.
It's a really common trap for someone working usually at one level of abstraction and not deeply understand other levels, to not understanding why a language or library is the way it is because if needs to support others users needs that are different to ones own - I've done it myself enough to detect the pattern, and seen lots of other people do it. Lurking on design committee discussions can be eye opening!
We've asked you twice before not to do this and now you're at it again, so we've banned the account like we said we would. If you would like to comment within the guidelines, we'd be happy to unban your account.
Are the complaints about lack of generics really a minority thing? Writing separate functions to sort different types just strikes me as ridiculous.
EDIT: My original tone was a bit nasty in retrospect. Did a little research and while I still am on the generics side, the current situation seems at least workable for a good number of use cases.
My concern is less about writing a bunch of separate functions, but rather the way this hampers the abstractions that are available to you everywhere in the language. You don't have map or fold! And that's only the very tip of the iceberg.
Yeah, I wish go had more functional stuff, like .map(), .filter(), etc.
On the other hand I enjoy that when I pickup a package someone wrote there is not a bunch of different meta-programming using templates.
Generics sometimes lead people (including myself) to over-engineer solutions... usually because we want as much compile safety as possible. But at what cost in complexity.
I groan every time I have to implement the 15th type-specific loop implementation of what I'd do with a single map or fold in Ruby/Elm/Haskell/JS/TS/Crystal/every other language I use. It's not a lot of effort but it's a lot of mess and cruft.
i wish i could laugh, but i can't. the lengths people will go to work within such an impoverished language, and by means so antithetical to the go philosophy.
Apparently, the project leaders see it as a lower-priority (though not unimportant) issue. Looking at the adoption figures, they seem to be right.
I personally stay away from Go due to lack of generics and other expressiveness issues. People who have to work with it write code generators on top of the compiler, because the compiler team won't include it into the language. (I can see how it's not an easy thing to do; Russ Cox wrote a nice piece about it.)
Java prior to version 5 had the very same problem. It was wildly popular nevertheless. It took Java 8 years to gain support for generics, though, about as long as it took Go to not yet obtain them. (By that time, Java was widely considered the Cobol of 21st century; I think Go must be successfully stealing that crown now.)
That's kind of part of the problem - with C++, or Java, or C#, you can write in 15 different styles, syntactically valid but quite possibly unreadable to another programmer who is experienced in the language. That's because there isn't one idiomatic standard for the code, there's 15++, and the language has the complexity that enabled that mess.
If you want to work in a kitchen sink language (and I often do haha), just use one of the many available.
But perhaps you're missing the value of simplicity? It is after all the main strength of Go, and a rare commodity in software engineering these days.
Overall I think it's a shame to have less choice, and we lose something by making all languages too similar (in both features, and at the meta level in complexity).
I have had the need to sort data rarely enough that it has not been a real problem to me (most of the time that data came out of a relational database that did the sorting for me).
But when I did have the need to sort stuff, I have found it annoying. Even C has a more convenient solution for this problem. (Admittedly, Go's sort.Sort can work for data structures other than arrays/slices.)
Like I said, it has not been a sufficiently large problem to really bother me, but it is not a pretty solution, IMHO.
Of course, one might argue that the creators of Go knew that sorting things was not such a common problem for their target audience, and thus they made the trade off to make sorting suck in return for overall simplicity; Go's type system makes it practically impossible to implement a type-generic sorting function like C's qsort(3) without sacrificing performance or making the language more complex.
So maybe that is one of the trade offs we have to make. I still wish for a better solution, even if that may be impossible without turning Go into another C++. And if you like C++, that is totally fine, it has a number of very big advantages. But then you do not need Go to become another C++ if you have the original right there; and even if you wanted to get away from C++ without giving up the benefits it offers, D looks like a more promising alternative.
But this is something you often need to do for any non-trivial type, even with generics. There's a reason that C++ std::sort<> takes a comparator, or why Rust requires you to implement the 'Ord' interface.
Again, it's a little clunkier in Go, but not unusably so.
You need to define how to order things in other languages (though not in languages where you can automatically derive implementations like Haskell or languages with built-in polymorphic comparison like OCaml) but you don't need to define how to swap elements over and over.
Yes, I'm aware. That's the clunky part that I was referring to (although, you can still avoid it for slices, and simply pass a single compare function.)
Go is far from my favorite language, but the sheer amount of bad criticism by people that clearly don't use the language annoys me.
A little boilerplate hasn't killed anyone. If you're talking about "100s of different Enterprise Business Objects (TM) structs", something is probably off in the overall program design and/or code-gen should probably be introduced regardless of the 'sort' (and related typically-generics use-cases) question, as that sounds like something to be largely derived from pre-existing schemas of some sort..
Yes, it is minor. Go has interfaces, so you just write a Comparer interface and sorter that takes two Comparers and then anything implementing Comparer is sortable.
*Note: author has written basically nothing in Go and only has a passing familiarity.
So you define the Comparer interface with a Compare method. What does it look like?
If I have a struct X, then I might write it as:
interface Comparer {
Compare(other X)
}
But wait, now I have to define a new interface for every type since "Compare" takes the type X in its signature so it doesn't work for type Y... If only I could define an interface that was for an unknown type T and then Compare was for that.
But that's exactly what generics are.
You know how Java has .equals? Go doesn't have an equivalent concept. Test code is neigh unreadable because there is no generic way to compare two structs of the same type. This is a similar problem.
I am admittedly thinking of an interface from how they work in Java, so I may be making incorrect assumptions about how they work in Go, but wouldn't I have to do that anyway? In what sense can the compiler work out how I want to compare my types? If I hand it some vec3s, for instance, does it know I want them sorted by x value, or by length?
By defining an interface that assures the compiler each type has a compare(x) method, I can write a generic sort function that takes any two comparable objects and sorts them based on whatever the class of those objects decided was the ordering criteria.
If your `Comparer` is an element type (as opposed to Go's `sort.Interface` abstraction over collections), this is going to be horribly unperformant. Suppose your `Foo` type implements `Comparer`, and you have a large `[]Foo`. Then you'll first have to iterate over each element in `[]Foo` and add it to your `[]Comparer`, probably with an allocation per element. Then each invocation of `foo.Compare()` is going to be indirect as well (in other words, an interface lookup and a function call, i.e. no inlining). Mind you, this is still faster than many languages, but it's not the kind of performance people expect from Go.
The primary differences (I think) are that everything in Java is already a pointer, so there isn't an extra alloc to make an interface. The same is true in Go if your comparables are all pointers. Probably the more significant difference is that Java has a JIT compiler, which may be able to inline all of those calls to Compare(). This is largely why Go's `sort` package abstracts over the collection, not over the element.
I don't think there is a technical reason. It's probably not something they'll do for a while because it probably requires some significant reorganization of the compiler and making a passably fast implementation is probably quite hard (the Go community places a premium on fast compiler times, rightly or wrongly). Also they seem to value predictable optimizations. Not sure how keen they would be to add an optimization that works until a seemingly inoccuous code change prevents the compiler from guaranteeing that all elements in the slice have the same concrete type, making performance (probably) significantly worse.
Again, I don't necessarily agree with the Go team; I'm just guessing the are some of the concerns they're weighing.
Ah I misunderstood the previous comment. Sure, if you have a list of pointers to values that satisfy a given interface, dispatching at compile time would not be trivial.
It's not about sorting, it's about every single abstract operation on a collection or other type of container. You either have to use primitives, or reimplement everything yourself on each new type. Most people just use primitives. This proliferation of primitives is what I actually dislike about reading and writing code in Go, but it's caused by not having a way to define abstract data types that work well.
I’m not sure about you, but it feels very reasonable to me. It’s not anywhere near the top of my list of pains that I feel when working with Go everyday.
interfaces are a poor substitute for generics, but that's by design. the minute they add a reasonable implementation of generics Go will begin to metastatize into something unrecognizable as people will no longer be bound by the limitations of the already existing core generic types. the core developers really do not want that to happen.
it's a highly opinionated language and for some reason some people enjoy writing mountains of for loops so that their code can remain "simple" as they produce a maze of twisty funcs all alike. i mostly see a for loop or two per func with a map and some slices repeating the same patterns over and over. that's the way the language designers want it.
i work with a lot of go programmers and they are all fine and good programmers. that makes it even harder to understand why they enjoy all the boilerplate and even defend it.
Ignorant here (I've never done database work):
What's wrong with asking the database to do the sorting for you? (assuming you do work that involves a database. Perhaps this assumption itself is the problem?)
I understand why that would make you uncomfortable. ;-)
But to be honest, more than 50% of the cases where I needed data to be sorted in a certain way, that data came out of a relational database, and adding an ORDER BY-clause to the SQL query was so much easier than doing it myself.
I do agree with the second part of your comment in that Go has a certain type of application where it really shines. But that type of application is not uncommon, and when you hit the sweet spot, it really shines.
care to enlighten me? if you have an index you could get the sort for free, also you never pull all results, so why would you pull all, just to sort, on the web I would love to work more in ram, but since you assume a server will crash, you need to save the actual state in the db.
I didn't down-vote, but what jumps out to me is the assumption that you'll generally be pulling data from a database. Yeah, that's almost certainly true in a web-application, but it's not going to be nearly as universal in a systems-programming niche which is where Go appears to be excelling (as perceived by someone outside of the Go community).
So ease of implementing sorting in your core language without making assumptions about the operating environment of code written in that language sounds like a reasonable demand.
> by far most of the Go developers still prefer to use the language without generics
I've been writing Go regularly for at least 5 years, and my guess is that at most 60% of Go developers prefer no generics. I also think that number is climbing.
Not the OP, but here are my 2¢. Introducing generics in a language implies a deep revision of the type system, which risks to become much more complex to understand. Moreover, this might have a bad impact on compilation performance (compare C++ compilation times with Go compilation times and you'll understand what I mean).
It sounds like you're saying Java's generics are somehow superior to C++ templates.
For those who don't know, C++ generates a separate instance of the code for each type which means that it can operate directly on a value instead of through a reference/pointer and it also makes it possible for the compiler to inline the type-specific code in many cases. Ie., it has the potential to be much more efficient. That is why it works the way it does. The downside is that the code generation slows down compile times, as you noted.
Java simply casts a reference to an instance of Object to the type on behalf of the user. So you effectively have generic code the way it's done in C (void*) and Go (interface{}) but without the explicit casts.
Maybe the JIT offsets many of these inefficiencies but making that comparison is beyond me. I only bring this up because you made it sound like Java got generics completely right and C++ got it all wrong, and with the amount of flak C++ gets these days I think it deserves a little help now and then.
I didn't intend it to come across like that. C++ is how you have to do aggressive type specialisations and optimisations in the absence of a JITC. Java's JITC is able to do many of the same things at runtime as C++ does at compile time, but it's less predictable.
I was not referring to templates only, but to the overall complexity of the C++ language. Examples: syntactic ambiguities, the preprocessor... Templates are a big part of the problem, but not the only one for sure. Languages like Free Pascal have outstanding compilation times because they privileged language simplicity, and IMHO Go falls in the same ballpark.
To be clear I prefer generics. The cases for why other Go developers don't want generics seem to mostly fall on "it will change the language / encourage people to write stupidly complex code" to "it's too hard to implement". The first one is valid--Go's constraints give it this nice property that there is (more or less) one obvious way to write most programs, and that will go away with generics; however, I think that cost is worth the gain. The other criticism seems like a cop-out; the Go team has far and away more than enough talent to slap generics onto the language.
Not OP, and this is only one aspect to consider, but it's from experience - when generics were added to C# the language became nicer to use, but it caused a lot of churn and added complexity. The base libraries have the original non-generic classes as well as newer generic ones.
As I've written above, there's huge potential to be the language that doesn't churn, when just about everything else does these days.
yes, but those of us who would desperately like to use Go because there are vanishingly few GC languages that compile to native exe AOT, won't because of no generics. So it is a bit of a tautology.
How useful they are depends greatly on what you are doing, and programmers do a great many different things. For many kinds of library development, they can save you massive amounts of time and code, and/or lead to much better performance vs the workarounds available.
I wonder how many people who prefer Go without generics are coming from C++ templates, or Java generics, vs C# or F# generics.
To be clear, I agree with you. I was just responding to the OP's claim that the Go community overwhelmingly rejects generics with my perception that at most 60% of the community feels that way. I am very much in favor of generics.
Not OP, but I can't execute a directory tree. I always seem to need a runtime, and often additional libraries and a bunch of `$*PATH` munging so the compiler locates the _correct_ dependencies.
What amazes me most about Go is that they managed to successfully pitch a C-like systems language that does not promote use of shared libraries. About six years passed before they added an option to create them.
Were there many complaints about the absence of shared libraries originally?
Whenever I have mentioned the benefits of compiling C programs as static binaries and that in some cases with todays hardware one can have enough memory that shared libraries may not be necessary in order to conserve memory (one of the original goals of shared libraries), I have encountered substantial resistance to the idea. Perhaps some folks are interested in shared libraries for reasons other than memory conservation.
The deployment time benefits of static binaries far outweigh the resource saving benefits of dynamic linking. I'm speaking from experience with C++. There is also a latency boost for high CPU intensive processes.
The Go community mostly deploys network server daemons to its own datacenter infrastructure. C and systems programming in general also target end-user devices, where it isn't the programmer's memory to spend.
The open-source community already has a mature ecosystem for dealing with shared libraries via package managers and distro maintainers. In a company's proprietary backend it's almost certainly cheaper to throw memory at the problem than to spend engineer time crafting and maintaining a coherent/compatible set of packages for its various backend services.
In my experience, shared libraries can simplify deployment as well; say you’ve got a 100 programs using the same library, and you need to change the implementation. With a shared library you only need to build and deploy one artifact, you don’t need to relink and redeploy 100 programs.
> while paying much less attention to the vocal minority's complaints
That's debatable. Those who can't stand the language don't bother using it,therefore don't bother complaining about it.
My point is Go biggest critics have already abandoned the language long ago.
Go reminds me Rails. It had a huge success 8 years ago but since all other languages have caught up when it comes to RAD webdev. The JVM and others will eventually catch up.
i don't think you can "catch up" with go, because it has aimed at being minimalist. catching up by removing major features to a language isn't something i've ever witnessed.
You can absolutely catch up with the concurrency model, on the single binary deployment, and a other features. Go isn't "minimalist", that's false, go look at the reflect package, it's complex as hell.
> ... while paying much less attention to the vocal minority's complaints (generics, package system, etc).
It is much more difficult not to add a feature than to add it, and the ability to reject even important feature requests is very important for the survival of a system in long term. This observation is formulated in "Getting Real" (https://gettingreal.37signals.com) as "Forget Feature Requests" and "Start With No".
People want generics because they think every language should have generics.
What they don't know is the exact cases where the lack of generics causes a real-world problem for them. This is what the developers are requesting at the moment, in order to possibly bring generics to Go 2.
Every statically-typed language needs generics to allow a function to be used with more than one type. Otherwise you throw away most of the type info and end up with the same problems dynamically-typed languages have.
This is exactly my feeling. I don't want generics if I have to pay anything for them in build time, or if it limits go/ast or go/types. A lack of generics has been a pain point a couple of times in my current project (beyond what very simple code generators can provide), but crazy fast build times have been a massive benefit.
Imagine how much wailing and gnashing of teeth there will be if Go 2 delivers generics but with triple the build time and +50% binary size... if you thought the minority was vocal now, wait til you see that!
Like pretty much every successful programming language.
Most of them have one original goal, and a core philosophy to go with that goal and that guides the compromises.
Take C for instance : its original goal was to write UNIX. Because of this, it has to be low level, portable, and efficient. These are the important things and that's why people use C. Features important for writing UNIX stuff get priority, this ensure consistency.
Go is Google's language, made to be effective at doing what Google does. And its direction ensure that people who follow Google's way of coding are happy. There are other options for those who don't like it.
Go is an example of how to be extremely successful by inventing Unix and then going obscure for 30 years doing stuff like Inferno and Plan 9, and making a comeback when Google shows up.
