Eight years of Go(blog.golang.org) |
Eight years of Go(blog.golang.org) |
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.
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.
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.
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.
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.
No, it doesn't.
Golang generics is the second most voted issue on GitHub itself: https://github.com/issues?q=is%3Aopen+is%3Aissue+sort%3Areac...
(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.
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.
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.
But it must be explained I guess.
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.
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.
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.)
*Note: author has written basically nothing in Go and only has a passing familiarity.
I think its just a minor problem compared to all benefits.
Does this refer to static binaries?
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 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.
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.
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".
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.
I don't know that the majority want generics at the expense of compile times or other possible tradeoffs.
Those who care about generics enough probably just avoid Go and use another 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.
How do you know that go would be less popular if it had generics and package system?
- Dep handling was never considered. Makes sense given Google's monorepo but thats not how the world works.
- Stdlib just loosely wraps posix features with many C flags copied verbatim. These APIs are old and could use a refresh but Go never bothered.
- No easy way to construct arenas/pools. Once you go down this route you have a great headache of releasing in the right places. The GC doesn't cut it, you need pools sometimes
- Debugging basically doesn't work on some OSes. No easy way to attach gdb and see what's happening. Doubly so if you use Cgo
- Similarly, Go doesnt bother to hide the differences of different OSes. Up to you as the programmer. Again not surprising for Google's all Linux world. If everything is Linux then OS difference doesnt matter. But even Python does a better job here.
- Logging is poorly thought out as evidenced by multitude of third-party log packages. Anemic compiler means you can't get verbose logging without paying a performance penalty.
- No RAII. Defers are a lazy attempt at this, but they're not even close to being as good as RAII. This is probably the biggest point where you realize Go can't dethrone C++
- Tricky Close() semantics force you to architect entire program around who will close() things at end of their lifetime. Lots of terrible hacks ensue when people build something that works but realize close ownership is ambiguous and rightfully don't want to rebuild it all
- Channels don't have a good way to deal with errors. You're forced to come up with an ad hoc solution to deal with your graph of goroutines/channels when one node errors
- No supervision tree. Erlang existed far before Go but they didn't learn from this key feature. But it would greatly enhance Go to have it
- Hacky reflection semantics that cause subtle runtime bugs when a JSON struct field's name starts with a lowercase letter. And of course, there are no generics, the larger issue here.
I was hopeful that Go would fix some of these things before it went 1.0 and locked in its syntax. Sadly that didn't happen as it was likely already locked in at Google. Go is ultimately kind of brain dead, useful for some very particular features but not so compelling that it can replace any other language.
1. Probably the best ecosystem out there.
2. Go routines
3. (Enabled by (2) actually) `defer`
4. That I can add interfaces implementations to structs I don’t own
5. No exceptions.
Actually (5) is one of the few things I don’t like about Haskell.
If Go had ADTs and generics it would easily be my favorite language.
Edit: and of course the channels.
Edit2: yeah, i have no idea why i connected (2) and (3). Had just woken up. No idea what I was thinking.
And this is how the "network effect" propagates. As the customers of cloud services also begin to experiment in Golang. And discover the holistic ecosystem of distributed systems packages.
Even Blizzard with its massive C++ codebase is gaining converts
The quote fits perfectly for the design of go.
Or using characters from the Canadian Aboriginal Syllabics unicode block to emulate generics.
Just to accentuate some of the neat things you can do with Go, watch: 'Can you write an OS Kernel in Go?' from the Golang UK Conf. https://www.youtube.com/watch?v=8T3VxGrrJwc
https://twitter.com/pasiphae_goals/status/923820615022399488
> Fact #38: go is supposedly a garbage collected language, but it has not once deleted itself nor any of my code.
pretty hilarious.
https://commandcenter.blogspot.com/2017/09/go-ten-years-and-...
Changing something then having to wait 40 seconds for java to recompile drive me crazy, also same for tests. Yes would love to have a package system, but is coming.
What should we be using instead?
https://blog.cloudflare.com/arm-takes-wing/
This would have a positive impact on Google, too, as the more server chip competition there is, the cheaper it will be for Google to buy those chips for its cloud services.
Conda goes some way. Think of something like virtualenv, but not specific to python. I would be happier with something that had fewer features than conda, but where critical features were easier. Example: setting up a package server should be trivial.
I think we do not yet have the git of dependency systems, with the gravity to draw in the community and for people to regard it a solved problem. Maybe the most efficient route would be: find a way to get Linus pissed off about it.
Large projects use a litany of different tools like glide, dep, godeps, vndr, govendor, etc. that managing all of them is a pain.
What makes it worse is that Golang's official solution seems half-baked when compared with other solutions out there.
I disagree with these. Go runtime/stdlib is architected to work around many many POSIX headaches and design bugs, hiding them completely from programmers, and to be fully portable. For instance:
* Concurrency is completely redesigned (goroutines). * Signal handling is redesigned and doesn't cause bugs when interacting with concurrency. * Forking/Exec'ing is redesigned not to cause fd leaks in subprocesses (all file descriptors are marked as O_CLOEXEC, in a race-free way), nor have races while interacting with concurrency * Sockets are exposed through a higher-level API (Dialer/Listener). * epoll is not exposed but transparently used by a single thread to handle all supported file descriptors without wasting OS threads, to improve performance
In fact, I think the only thing that is pretty much low-level is os.File and filesystem access in general, which tends to expose lower-level details.
Sockets are actually another good example. If you need to tweak then at all, you get to use the same old horrendous POSIX names for everything. No name aliases?
This would suggest using an actor-like model, which is pretty senseless for single-machine usage. It's totally understandable for Erlang, where the VM spans multiple machines, so everything is unreliable, but in Go, I take it for granted, that my goroutines won't "just crash".
I'm not sure, but I think this also ends up being good for modelling interactions with good performance, as you know where you do network calls, where you have reliability, and where you have instant local calls. Though not to say that Erlang applications aren't blazingly fast too.
Supervision tree gives a structure to put whole subsystems somewhere, including their boot initialization and shutdown (not just restarting it at crash), allows to spawn workers while keeping usual logging/crash monitoring for free, gives a way to inspect the system at runtime (much easier debugging), and allows to run several different applications in the same VM space, which is a flexible way of combining code. I can, for instance, run a CouchDB instance with bolted on my own HTTP server that exposes monitoring data or an administrative interface. It cannot be done in Go (or any other language, barring maybe Lisps) without modifying source code.
And no, none of this "spans multiple machines", it all works and helps on just one single node. Maybe except for debugger, where you spawn a shell node from which you operate.
And yes, your goroutines will "just crash" in situations you haven't expected, as every non-trivial daemon experiences crashes on transient bugs. Though in Erlang transient bugs don't bring the whole daemon down. Saying `my goroutines won't "just crash"' means `my code and code I use as libraries doesn't have bugs, ever'.
For instance, you can’t forget to close a socket, release a lock, or log the actor state and stacktrace, since these things are handled by the VM and supervisors when an actor dies. These are nice properties to have even in a single-node system if you’re aiming for high reliability.
I do agree though that a supervision tree doesn’t make as much sense in Go, since the VM does not provide the cleanup guarantees and strong process isolation that make the Erlang model really workable.
[1] Yeah yeah, all input should be well specified. Could you please inform the vendors that their programs are spewing unspecified crap at me? Thanks.
This is the one thing in your list that I don't recognise. What is a supervision tree? Can you (or another Erlang programmer) point to your favourite reference?
In Go, if a goroutine panics for some reason it just dies on its own and the world does not know unless you have some sort of ping service or you specifically send a notification from a defer.
In Erlang, if a process faults and it has a supervisor, the supervisor gets a message that one of its children died with some additional metadata, it can then log the issue, restart a child, … This also led to an interesting "let it crash" philosophy (since Erlang processes have isolated private heaps a process dying also cleans up any potential data corruption in the process's private state, this is often considered a feature, but at its core it mostly avoids processes dying unnoticed.
Incidentally, supervision is actually the result of two individual features: linking and trapping. Linking means that when one process dies with an abnormal status (any reason other than regular process exit), all process linked to it will also die (the EXIT signal gets propagated through the link), which is repeated until all linked processes are killed, trapping lets a process handle the incoming exit signal in code rather than automatically suicide
Finally, because supervisors and supervision trees are so common the Erlang standard library provides generic behaviours which let developers declaratively set up which strategies they want in their supervisor, the maximum restart frequency (beyond which the supervisor consider the system's broken and shuts down), ...
There is nothing like Django in Java land? Instead you are sent into a confusing mess of interface standards like JPA and implementations (hibernate, ebeans, ...) and little guidance how to choose.
In the process of hacking on my PureScript2Golang "transcompiler", I've realized that under the hood ADTs, also known as "tagged unions", will likely more often than not be represented exactly as just that: a "tag flag" and a data pointer. (Of course if all of an ADT's ctors are nullary, an enumish int will do the trick just as well --- I doubt this gains anything over interface{}-boxed 0-size struct type-defs though in reality.)
Now the natural "box"/container for this tag+content pattern in Go is the `interface{}` that can hold as 'content' any of your "constructors" (whether it be a struct or type-alias or prim type), plus your 'tag' pattern-matchings translate to Go's type-assertions. You see this also whenever ADTs are translated to JS or OOP languages, in some manner the "type" tag is carried along to be able to switch-case on.
Anyway, you can do poor-man's ADTs as per above today. The catch is that you get fewer compile-time checks (won't check for pattern exhaustiveness in your switch-cases, or illegal/impossible/invalid (as per your custom "dumb" ADT layouts) type assertions).
But anyone who's done some linked lists or devised parser ASTs in Go has written "ADTs" in this manner --- whether by intention or inadvertently =)
Personally, I don't care about Generics now that I'm aiming to generate low-level Go code for PureScript's parametric polymorphism and higher-kinded types system.. --- expressive beyond the old-school oop/imperative "generics" band-aid ;)
> That I can add interfaces implementations to structs I don’t own
Wait, did I miss out on some new feature only recently introduced? The way I parse your above statement, it sounds like you could define methods for receiver types imported from other packages, is that what you meant? Or did you simply have classical workarounds in mind, such as type-aliasing or set-the-"method"-as-a-struct's-func-typed-field?
The order in which defer statements are executed is predictable, unlike goroutines.
For signaling error conditions that the caller has to expect and handle, you have the `result, err = func(...)` idiom, and a compiler that would warn you if you forget to use the value of `err`.
If Rob Pike's opinion on this is not enough, here's Martin Fowler saying essentially the same thing: https://martinfowler.com/articles/replaceThrowWithNotificati...
In general: http://wiki.c2.com/?DontUseExceptionsForFlowControl
This usually makes the error handling much better and better thought through.
You can see the same thing happening in all the functional languages using the Either monad instead of exceptions.
Haskell has exceptions FYI
With exceptions you most often just let them trickle up the call chain, which is the same thing you often do with err, just return it.
And the returning the err works much better when doing async. Cross thread exceptions are a PITA and you are basically back to just returning an error obj.
Rust seems on the right path, go ... well do you even have package management after 8 years? No..
What other systems do you compare it with? Its not the best I guarantee it...
With ADTs, using a sum type instead of the `result, err = func(...)`, would be an obvious thing to do. But the next thing you'd consider would be `bind` / `>>=`.
> 1. Probably the best ecosystem out there.
it will when it gets an acceptable PDF library, better enterprise integration (SOAP and co) and an actual debugger (and no Delve isn't good enough given how it often fails at basic debugging).
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.
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.
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!
If a goroutine panics and is not recovered, it not only dies but tears down the whole process. This seems to be the more appropriate approach for a language with pervasive shared state (locks, etc.). Erlang is quite different here, as you say.
Restarting or otherwise dealing with the exiting process is best left to the service manager that started it.
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.
But as long as it is humans writing most/all Go code, fitting a human brain well is a valid design choice.
Yes, it has its fair share of problems. But for now, I find it preferable to anything else we have got.
Sadly it feels more like Oberon-07 than Modula-2, feature wise.
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.
Go is radically minimalist compared to other languages - it leaves a lot out, most notably inheritance.
Earlier first approach, won't currently compile due to deps: http://github.com/metaleap/gonad-coreimp
Auxiliary stuff currently dumped in: http://github.com/golamb
For a fun ps2go comparison, side-by-side:
https://github.com/golamb/test-pscorefn-src/tree/master/src/... <-> https://github.com/golamb/test-pscorefn2go/tree/master/Mini --- lots to-do still =)
I have tried Go and worked with languages without exceptions in the past. The problem is the amount of error handling code I was writing time and time again. It might only be a case of returning an error but that is one more thing you need to think about instead of concentrating on the the domain.
Error handling in threads is a pain either way.
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.
And many more want Generics without having responded to the issue.
Issues are representative as a sampling, not absolute numbers.
> 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.
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.
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.
Apparently also not about sync.Mutex =)
> if you want to use an interface you just have to implement all it's properties
You surely mean "methods" --- don't interfaces work like that everywhere they exist?
Don't blame the language for your buggy code.
Unless otherwise stated, Go's data structures are not thread-safe. Maps are not thread safe.
In that respect Go isn't different from any other mainstream language with pre-emptive threading (C++, Java, C#).
Not really, for me Go is a bit like JavaScript.
I have to deal with Go thanks to Docker and K8s, doesn't mean I would use it when given the option.
Or any modern natively compiled language.
If you replace the two-value assignment with an `Either`, it feels very natural to also eschew the constant `if (err != nil) return err` lines, and adopt a continuation-passing style, the way you do with Futures in JavaScript. You could even consider some syntactic sugar around it, like the `?` operator of C# and Kotlin, or a full-on Haskell-like do-notation.
Note that generics is the highest requested change.
This is how you can sort slices of arbitrary types in Go:
https://play.golang.org/p/VHJW9lVY9b
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.
I..I can't believe you just said that. Such generalizations based on a single comment by an anon.
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.
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.
Which gets handled by the container scheduler
Not to mention that you have just introduced a very complicated piece of software to run a single daemon.
Sensationalism maybe?
WTF is wrong with me?? I should be banned from this forum for life!
It's quite common that some of these frameworks rely on community infrastructure that has several competing implementations, like JPA, but the point of a tool like Boot is that they picked all the implementations for you and documented it all centrally.
For example, one thing which seems to be worse across the board is database evolutions. Django will autogenerate an evolution in Python for you [0] and if necessary you can adapt the code. In Java land you have to write SQL by hand [1] afaik? If SQL is not enough, I don't know what to do at all.
[0] https://docs.djangoproject.com/en/1.11/topics/migrations/ [1] https://www.playframework.com/documentation/2.6.x/Evolutions...
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.
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.
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.
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.
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.
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.
In all programs I've ever worked on you don't want to have to check useless junk like that and just want the general exception handler to handle it.
sort.Slice(s, func(i, j int) bool { return s[i].X < s[j].X })Again, it's a little clunkier in Go, but not unusably so.
It's annoying, especially since basic generics are simpler than interfaces.
> If you're talking about "100s of different Enterprise Business Objects (TM) structs"
I don't write enterprise software. I sometimes need to sort things.
Can you explain why you would prefer no generics to this dumb junior engineer who wants to be enlightened?
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.
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.
see https://blog.rendle.io/what-ive-learned-about-dotnet-native/ https://stackoverflow.com/questions/29609993/difference-betw... https://docs.microsoft.com/en-us/dotnet/framework/net-native...
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 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.
If I have a struct X, then I might write it as:
interface Comparer {
Compare(other X)
}
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.
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.
Never the less, I find that generics usually are just an over-engineered solution to any given problem.
Again, I don't necessarily agree with the Go team; I'm just guessing the are some of the concerns they're weighing.
That said, it does not argue against exceptions. So, I am not sure what your argument is.
So instead of some imagined return of "int or throw Exception" you now have "(int, error)", which basically means that the result of a function call can be any of these four options:
- ( value, no error)
- (no value, error)
- ( value, error)
- (no value, no error)
And due to the lack of proper ADTs you can't even properly model "value OR error" manually.
Accepting for the moment that Go has no exceptions and and error returns are the way to go, the first two cases make sense.
The third case ( value, error) is actually useful in several scenarios. For instance, considering you're writing bytes to a stream that fail partway. The value is the number of bytes return so far and the error is the error that was encountered. In fact, this is the signature that the ubiquitous io.Writer's Write method uses.
If all you had was single return values (aka "int or throw Exception"), how would you model the io.Writer?
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.
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 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:
// MarshalBinary implements the encoding.BinaryMarshaler interface.
func (t Time) MarshalBinary() ([]byte, error) {
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'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.
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.
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.
type T struct{}
var _ I = T{} // Verify that T implements I.
var _ I = (*T)(nil) // Verify that *T implements I.
you can use go-oracle (https://camo.githubusercontent.com/3fb1d62bbc7b1306da783f395... that!
https://docs.google.com/document/d/1_Y9xCEMj5S-7rv2ooHpZNH15...
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.
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.
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.
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.
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!).
This is not an problem, because a single return value is _not_ everything one has.
Who are the authors of https://golang.org/pkg/io again?
Yeah, 90% of Go devs agree with you.
10% think it is a really great idea.
So you can never be sure without reading the documentation.
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.
What Java does have (since 8) is default method implementations in interfaces.
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.)(Another useful link explaining that statements resembling instance variables in interfaces are in fact constants: https://coderanch.com/t/178630/certification/Instance-variab...)
Java has near-instant compile times and has generics. Likewise for Kotlin. Generics don't have to mean slow compiles.
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.
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++
}
for instance, in a for loop ranging over a slice:
for _, i := range some_slice {
go func() {
something(i)
}()
}
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.
No, DO blame the language if its the one that enables and allows for said buggy code when it could as well prevent it.
Case in point: http://lambda-the-ultimate.org/node/3186
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!
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).
//compile_test.go
func TestThatThisModuleCompiles(t* testing.T) {}
//list of "type implements interface" tests
var _ mymodule.MyInterface = myothermodule.MyStruct{}
...
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.
As it's return type is MyInterface, but it actually returns myStructure which causes the compiler to check the interface satisfying.
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.
for (int i : someCollection) {
pool.execute(() -> something(i));
}