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Proposal: Go should have generics

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Re: Proposal: Go should have generics

#101

Post by teps »

What people think of generic package instead of fine grained generics? https://docs.google.com/document/d/1vrAy9gMpMoS3uaVphB32uVXX...

I think they would really fit the language well. The good part is:

* Only the package and import statement change, the rest of your code stay the same and is not cluttered

* They are easier to reason about as it is more coarse grained

* They do not break the compatibility

The the bad part is:

* You cannot implement filter/map/reduce (but being able to implement them would conflict with the orthogonality of the language)

* It could lead to code bloat, but not more than manually copy pasting the code.

Re: Proposal: Go should have generics

#102

Post by kqr »

mattlondon wrote: post #68

I can feel the pain on the Sort issue. I've personally found sorting annoying in Go - I had a bunch of structs representing data entities from a database that all had the same field and I wanted to be able to sort them by this field. Seemed like a LOT of work (basically implementing the same sort that was 99% identical for every struct) or use weird reflection-workarounds to get this to happen. In Java I would not ev…

Completely oblivious about Go, but can you not provide a key function to the sorter that reaches into the struct and pulls out the field you want to sort on? (And presumably explodes in some spectactular fashion if it doesn't exist.)

Or is that the "unsafe" reflection you're talking about?

Re: Proposal: Go should have generics

#103

Post by isuckatcoding »

kqr wrote: post #99
isuckatcoding wrote: post #98

This makes me wonder if this has happened before in another language. I can totally imagine 10 years ago someone saying "oh we'll never need that in PHP" and voila 10 years later you've now got feature X in PHP. Any of you wise old timers want to share such examples? Does history keep repeating itself with these sorts of things?

Generics in Java? Anonymous functions in Java? Most everything in Java?

I guess I was think of the community mentality and how it evolves as well.

Re: Proposal: Go should have generics

#104

Post by junke »

enneff wrote: post #85
xiaq wrote: post #77

Earlier quoted context omitted.

Write a code generator. That's the best solution at this moment.

Or, y'know, just copy and paste the trivial code. It should take all of 30 seconds. Not saying that it's pretty, but it's quick and easy.

And that's exactly why I am not convinced that Go is as maintainable as often claimed. 30 seconds for you, but how many hours for the poor souls who will come after you and ask: should I change this copy too or is it a separate case?

It reminds me of this: http://typicalprogrammer.com/abject-oriented/

Re: Proposal: Go should have generics

#105

Post by trhway »

bigdubs wrote: post #7

After watching Rob Pike's Go Proverbs talk I am pretty convinced generics, as much as some would want it, will never happen. He proselytizes "just copy a little code here and there" quite clearly, which is at odds with the complexity that generics would add.

mental exercise - replace C++ with "generics" and git/kernel/etc with "Go" here http://harmful.cat-v.org/software/c++/linus

Re: Proposal: Go should have generics

#106

Post by boulos »

ktamura wrote: post #12
bigdubs wrote: post #7

After watching Rob Pike's Go Proverbs talk I am pretty convinced generics, as much as some would want it, will never happen. He proselytizes "just copy a little code here and there" quite clearly, which is at odds with the complexity that generics would add.

This. For better and for worse, Go was designed for "simplicity", and generics are anything but simple. I'd be very, very surprised if Go thinks about generics in earnest anytime soon. I don't say this in anyway to eulogize Go: In some ways, Go is pathetically unexpressive. That said, it currently fills that gap for writing middleware between C sacrificing too much developer productivity and Perl/Python/Ruby/PHP sacr…

> I'd be very, very surprised if Go thinks about generics in earnest anytime soon.

I might agree if the submitter wasn't a person on the Go team trying to highlight some recent thinking ;)

Re: Proposal: Go should have generics

#108

Post by the_mitsuhiko »

agentS wrote: post #64
pcwalton wrote: post #43

Earlier quoted context omitted.

CLR-style just-in-time monomorphization is plenty performant: in fact, it's just about ideal. It's also not that difficult when you have a JIT when compared to the complexity you need for speculative optimizations of hot spots anyway. In any case, the .NET approach isn't an option for AOT compilers like those of Go. For Go, the only reasonable option is ahead of time monomorphization, which really isn't that bad.

Monomorphization is not a reasonable option, in my opinion. It forces the compiler to accept some truly awful running times for pathological cases. Atleast quadratic, probably exponential. For languages that have reflection or pointer maps for GC or debug information for types, it can force large blowups in space as well. Go has all three of these. The implementation would likely require runtime code-generation (or a…

If generics were not a studied and well implemented concept I would agree. But we live in a world where this is just not the case. I would take a slightly slower compiler with generics support any day over the mess that go devolves into because of the lack of it.

Re: Proposal: Go should have generics

#109

Post by the_mitsuhiko »

duaneb wrote: post #56
enneff wrote: post #52

Earlier quoted context omitted.

I think what's happening here is pcwalton is a language implementer, so when you talk about 'conceptual complexity' he thinks about how the feature is specified, whereas you or I think about how the users of the feature think about and use it. We're all talking past each other a bit, I think.

Well he answered me as if he understood me, so I am going to go ahead with that assumption. This thread is not at all difficult to follow. Anyone who uses rescue should be shot on sight--it takes a masochist to introduce panic as a stack unwind mechanism intended to be caught. The process should stop. I have never seen rescue used in the wild, so it seems as if the only thing this has in common with exceptions is sta…

A big problem with both Rust and Go is that the marketing says there are no exceptions, and because we all know exceptions are bad/slow/hard to understand that the languages are superior. I strongly object to this idea because from an implementation POV both Go and Rust are 90% there for all the complexities that exceptions cause but now nobody is aware of it.

(This is also why I'm a huge proponent of Results in Rust and disabling unwinding altogether)

Re: Proposal: Go should have generics

#110

Post by inglor »

mattlondon wrote: post #68

I can feel the pain on the Sort issue. I've personally found sorting annoying in Go - I had a bunch of structs representing data entities from a database that all had the same field and I wanted to be able to sort them by this field. Seemed like a LOT of work (basically implementing the same sort that was 99% identical for every struct) or use weird reflection-workarounds to get this to happen. In Java I would not ev…

This is stupidly easy with http://dl.acm.org/citation.cfm?id=2738008 - I opened an issue for considering something like this for go https://github.com/golang/go/issues/15295 hopefully I didn't err in posting it :)
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