6 ms·

never mind than MANY people dont need generics, and that generics have a significant compilation and runtime cost, in terms of time and memory. who cares right?

• vore 3y ago
  Many people don't need generics? Significant runtime cost? I would argue that everyone should be using type-safe collections like maps, lists, etc. (I know these are built into the language in Go, but they're basically special-cased generics). And, if anything, not having generics has more cost because you end up boxing your values to place into collections rather than letting the compiler monomorphize it. The compilation cost can be more expensive, yes, but it saves a lot of work you would be doing by hand. While Go has had generics for a while now, the vast swath of existing Go code doesn't. The situation is definitely improving but there is still a lot of non-generic legacy cruft.
  • 2h 3y ago
    > you end up boxing your values to place into collections rather than letting the compiler monomorphize it. you know that Go has interfaces right? and I dont just mean the "any" interface. you can write your own interface similar to io.Reader and others, then add types that implement that interface, then no type matching is needed. > non-generic legacy cruft AKA normal, fine code. generic code is not some magic pixie dust that makes bad code into good code. plenty of awful bloated slow generic code around as well.
    • emodendroket 3y ago
      What kind of argument is this? Nobody says it’s “magical pixie dust that makes bad code into good code.” It’s a way to avoid writing repetitive code over and over and the runtime cost can be insignificant depending on implementation.
    • vore 3y ago
      If you are using interfaces, the value is necessarily boxed as the storage for the value may be heterogeneous. Once a value is typed as e.g. `io.Reader`, dispatching to its methods necessarily requires a vtable lookup (i.e. runtime cost!). Compare this to parametric polymorphism where you can avoid the type erasure and perform static dispatch at compile time. Though, unfortunately, Go's implementation of generics ("GC shape with stenciling" instead of full monomorphization) still ends up incurring some runtime cost. With regards to your second point, there are definitely situations where generics are vastly preferred: type-safe collections being a big one. For instance, the standard library containers (https://pkg.go.dev/container https://pkg.go.dev/container) are still non-generic with no generic versions in the standard library yet. This is the kind of cruft I mean: generic collections can be turned into concrete collections with type safety, but not the other way around. I make no claims about use of generics making your code being absolutely good or bad, but I do make claims that use of generics can make your code less error-prone and more safe.
      • svnpenn 3y ago
        > I make no claims about use of generics making your code being absolutely good or bad, but I do make claims that use of generics can make your code less error-prone and safe. Right. this is the issue right here. people only see that Go didn't have generics, and they never stop for a second to think WHY Go didn't have them. Generics have an implementation cost for the Go project, and maintenance cost for the Go project, and end user negative impacts in regards to time and memory. but advocates often dont know or care about these drawback, and only howl that GENERICS ARE MISSING until they are added, consequences be damned. I'm just saying that while generics are useful in some cases, they are not always the right answer, and it shouldn't just be assumed that every language needs them, nor that any non-generic language "sucks".
        • alex_lav 3y ago
          > I'm just saying that while generics are useful in some cases, they are not always the right answer, and it shouldn't just be assumed that every language needs them, nor that any non-generic language "sucks". It's funny to me, because this comment chain exists because I said I got tired of rewriting the same functions with minute changes, the exact problem generics is intended to solve. I didn't say anything sucked, or even that I didn't like Go, just that this one aspect got tiring. And yet, this small comment lead into a person feeling their language was being attacked.
• alex_lav 3y ago
  > never mind than MANY people dont need generics, and that generics have a significant compilation and runtime cost, in terms of time and memory. who cares right? I'm saying that I wanted them...? I didn't say need. I was able to operate without them. I simply _wanted_ them. Also maybe consider the way you're communicating? I didn't say Go was wrong. I said I didn't enjoy it. I'm allowed to not like things, and I'm allowed to post about them. _Also_ this concept of "need" is amusing to me. You don't _need_ a garbage collector, or a statically linked binary, or static typing, or IDE support, or a debugger, or, or ,or. And yet, people _want_ them. > and never mind that Go has had generics for over a year now right? Their generics implementation is pretty bad IME. Interfaces lacking type parameters seems pretty untenable to me. I'd rather just not use them. > sometimes having a small, stripped down language Of all the things Go is, I wouldn't say its either of these. But also, if you respond, please try to not be so defensive. You can like Go, that is a valid thing to do.
  • mst 3y ago
    It's still on my "I keep meaning to play with this" list because I keep getting distracted by other shiny things but you might find gomacro interesting.
  • throwaway2037 3y ago
    Very good points about need vs want. Every time I hear a response to a reasonable software request at work with, "Well, do you really need it?". I pat my left leg. It's a good leg; I like it; Very helpful, but, sadly not strictly necessary.
• kerkeslager 3y ago
  The Gopher narrative timeline as I remember it was: 1. Generics are bloated and don't allow us to have a single-pass compiler, which we need. 2. You don't need generics because go generate covers all the cases that generics cover (please ignore that this is a second pass). 3. Go has generics!
  • throwaway2037 3y ago
    Yeah, for years C++ said they didn't need sealed/final classes. Then they finally added it. Similar "re-editing" of history was done. When new C++ standard libraries are written, there is now active, public effort to review what exists in other languages. Finally.
  • doctor_eval 3y ago
    My recollection of the timeline is a bit different: 1. The current proposals for generics are bloated and don't fit properly with our vision for Go. 2. We will do heaps and heaps of work over many years until we get something we like. 3. Go has generics! Also, AFAIK Go is not a single-pass compiler, at least not in the way I learned about compilers.
    • kerkeslager 3y ago
      > 1. The current proposals for generics are bloated and don't fit properly with our vision for Go. > 2. We will do heaps and heaps of work over many years until we get something we like. I suppose repeatedly suffering the pain of not having generics until you finally get enough of your community to admit generics aren't just bloat can be described as "heaps and heaps of work". ;) I'd love to hear what meaningful differences you think exist between early proposals for Go generics, and later proposals for Go generics. Or Go generics and generics which had existed in other languages for decades, for that matter. The result of this silly delay will be felt basically forever, because millions of lines of go were written with error codes, which could have been much-less error-prone option types. I'm not sure it would even be a good idea to start using option types at this point because it would create such inconsistencies in codebases. > Also, AFAIK Go is not a single-pass compiler, at least not in the way I learned about compilers. Correct! But it was single pass and that was very important because multiple passes were bloat. But multiple passes aren't bloat any more, because now Go has multiple passes and Go doesn't have the bloat of other languages. See how that works? "The past was alterable. The past never had been altered. Oceania was at war with Eurasia. Oceania had always been at war with Eurasia."