[go-nuts] Re: Thinking OO virtual function in Go

Am Dienstag, 22. November 2016 22:16:27 UTC+1 schrieb Tong Sun: > > Hi, > > How to architect the OO's virtual function in Go? > > Here is another blog that shows a way how to do this: http://objectscape.blogspot.de/2013/09/inner-pattern-to-mimic-method.html -- You received this message

[go-nuts] Re: multiple write headers problem

I think you problem is here jsonReservations, err := jsonConvert.ReservationsJson(otherReservations) if err != nil { rw.WriteHeader(http.StatusExpectationFailed) fmt.Println(err) } Instead try this if err != nil {

Re: [go-nuts] Re: Thinking OO virtual function in Go

On Wednesday, November 23, 2016 at 8:21:23 PM UTC+5:30, Tong Sun wrote: > I've tried to derive how to achieve a) implementation inheritance, >> followed by b) type substitution and c) enabling dynamic dispatch as in >> virtual functions in my blog post here: >>

[go-nuts] multiple write headers problem

Hey im running a go server locally using gorilla mux and net/http. For class we needed to create a room reservation system. I was testing the application on multiple compyters on the same network but when trying to create a reservation from both computer at the same time to test concurrency I

Re: [go-nuts] Re: Why doens't function type support comparision but channel type does?

On Wed, Nov 23, 2016 at 3:49 PM, roger peppe wrote: > Ian, what you say is true, but is also true of types and other objects too, > I think. I found some interesting anomalies playing around with the new > plugin package. We've worked hard to make sure that what I said

[go-nuts] Re: Frames for functions called via reflection are not shown in heap profiles

Let's just use https://github.com/google/pprof/issues/54 to avoid forking the discussion? On Wednesday, November 23, 2016 at 2:25:59 PM UTC-8, Dave Cheney wrote: > > Please raise an issue on the issue tracker, golang.org/issue/new > > On Thursday, 24 November 2016 09:11:30 UTC+11, Alexey

Re: [go-nuts] Re: Why doens't function type support comparision but channel type does?

Ian, what you say is true, but is also true of types and other objects too, I think. I found some interesting anomalies playing around with the new plugin package. Myself, I would have no objection to saying that two function values are equal if they are defined by the same source code and use no

[go-nuts] Frames for functions called via reflection are not shown in heap profiles

Hi Go team, We've got a report for pprof tool where call frames for functions called via reflection are not shown in the heap allocation profiles. The cause turned out to be that all frames starting one matching "runtime\..*" regex and its callees are pruned for heap profiles today.

Re: [go-nuts] Thinking OO virtual function in Go

​ As I said ​ ​ before, Go's flavor of OO is different from that of other languages. Don't try to map concepts one-to-one, or you will end up with very contrived solutions. Always look at the big picture (why am I doing this?) and don't get side-tracked by synthetic examples. Most important is

Re: [go-nuts] Short Variable Declaration Question

On Friday, 18 November 2016 10:30:45 UTC-5, Ian Lance Taylor wrote: > > I think the book is trying to stress that it declares out but does not > declare err. I agree that the sentence seems to imply that it does > not assign a value to out, but in fact it does both declare out and > assign a

Re: [go-nuts] Thinking OO virtual function in Go

On Wed, Nov 23, 2016 at 3:49 PM, Tong Sun wrote: > > On Wed, Nov 23, 2016 at 12:09 PM, Nick Patavalis wrote: > >> For this specific example, something like this: >> https://play.golang.org/p/FsorWRaLKk >> > > Thanks a lot Nick! > > I've simplified it a bit. Now it is: > > func (d Dog) Output() {

Re: [go-nuts] [ANN] RAIS: Fully open-source IIIF-compliant image server... and BONUS: the exciting story of how Go made its way into UO Libraries

Great story and congrats on your project On Wed, Nov 23, 2016, at 06:24 PM, Jeremy Echols wrote: > *Project:* > > This one's been out a long time, but I wanted to get to a place where > it felt solid before announcing it to this list. RAIS >

Re: [go-nuts] Thinking OO virtual function in Go

On Wed, Nov 23, 2016 at 12:09 PM, Nick Patavalis wrote: > For this specific example, something like this: https://play.golang.org/p/ > FsorWRaLKk > Thanks a lot Nick! I've simplified it a bit. Now it is: func (d Dog) Output() { // Presumably complicated stuff, not re-implemented

Re: [go-nuts] Thinking OO virtual function in Go

Thanks Chad. This is beyond my understanding for the moment, but I'm sure it'd be handy someday... Thanks. On Wed, Nov 23, 2016 at 1:17 PM, wrote: > Sorry, didn't read the whole thread, but here's how I tackled inheritance > in my cross compiler:

Re: [go-nuts] Windows DPAPI Golang package

That is the .net API; the equivalent C API is https://msdn.microsoft.com/en-us/library/aa380261.aspx Looking on godoc.org and github, I don't see any pre-made packages that implement this. However, you can use golang.org/x/sys/windows to call this function yourself.

[go-nuts] [ANN] RAIS: Fully open-source IIIF-compliant image server... and BONUS: the exciting story of how Go made its way into UO Libraries

*Project:* This one's been out a long time, but I wanted to get to a place where it felt solid before announcing it to this list. RAIS (https://github.com/uoregon-libraries/rais-image-server) is CC0-licensed and backs all the dynamic pan/zoom image-serving needs for Oregon Historic

Re: [go-nuts] Thinking OO virtual function in Go

Sorry, didn't read the whole thread, but here's how I tackled inheritance in my cross compiler: https://play.golang.org/p/UDp7nSLyl2. Granted, I am unsure about the unsafe thing, but the concept of a "method dispatcher" is likely what you need. On Wednesday, November 23, 2016 at 11:09:03 AM

Re: [go-nuts] Re: Why doens't function type support comparision but channel type does?

On Wed, Nov 23, 2016 at 7:00 AM, T L wrote: > > On Wednesday, November 23, 2016 at 10:35:59 PM UTC+8, Axel Wagner wrote: >> >> So, your suggestion is, to have functions be comparable, but have the >> comparisons always be false (unless compared to nil)? How would that be >>

[go-nuts] Auto Generated Google API and boolean values

I am using the auto-generated google api client and ran in to a problem with unsuspending a user (via admin/directory/v1). The Suspended field on the User object has the json tab omitempty and setting Suspended to false causes it not to get sent to the server. In my local copy of the library

[go-nuts] Re: Receiving results from a database

And in case you want to actually marshal it into a struct, I recommend giving JSON to Go a... go. On Tuesday, 22 November 2016 20:48:49 UTC, vanmuld...@gmail.com wrote: > > I just started leaning Go and I've been stuck on this for a couple of days > > Running on an App Engine dev server > > >

Re: [go-nuts] Re: Why doens't function type support comparision but channel type does?

(note: I'm exiting this thread now. I believe at this point it's reasonably clear, that there are good reasons for this and anyone not convinced yet won't be convinced by further arguments anyway) On Wed, Nov 23, 2016 at 6:30 PM, Axel Wagner wrote: > On Wed, Nov

Re: [go-nuts] Re: Why doens't function type support comparision but channel type does?

On Wed, Nov 23, 2016 at 4:30 PM, T L wrote: > If two functions do completely different things, they mus be two different > functions. > No. An example has been given above, here is another one: https://play.golang.org/p/uNN0G4gzFm > Two different functions can also do the

Re: [go-nuts] Thinking OO virtual function in Go

On Wednesday, November 23, 2016 at 5:17:11 PM UTC+2, Tong Sun wrote: > > Can you make it work on play.golang.org, from this code > https://play.golang.org/p/QjCtD9rGpa, according to your plan? > For this specific example, something like this: https://play.golang.org/p/FsorWRaLKk /npat --

Re: [go-nuts] Why doens't function type support comparision but channel type does?

On Wed, Nov 23, 2016 at 6:00 PM T L wrote: > > > On Thursday, November 24, 2016 at 12:06:43 AM UTC+8, Jan Mercl wrote: > > On Wed, Nov 23, 2016 at 4:55 PM T L wrote: > > > But we can't take addresses of formally declared functions and function > literals.

Re: [go-nuts] Why doens't function type support comparision but channel type does?

On Thursday, November 24, 2016 at 12:06:43 AM UTC+8, Jan Mercl wrote: > > On Wed, Nov 23, 2016 at 4:55 PM T L > wrote: > > > But we can't take addresses of formally declared functions and function > literals. > > Yes, so if you cannot have the function pointer (like in

[go-nuts] Windows DPAPI Golang package

Hello everyone, Does anyone know a Go package which provides an interface to the Windows Data Protection API? I am pretty much searching for the Go equivalent of this: https://msdn.microsoft.com/en-us/library/system.security.cryptography.protecteddata(v=vs.110).aspx

Re: [go-nuts] Why doens't function type support comparision but channel type does?

On Wed, Nov 23, 2016 at 4:55 PM T L wrote: > But we can't take addresses of formally declared functions and function literals. Yes, so if you cannot have the function pointer (like in func foo() {}; fp := foo) then there is nothing to compare so I don't understand what's

Re: [go-nuts] Why doens't function type support comparision but channel type does?

On Wednesday, November 23, 2016 at 11:47:19 PM UTC+8, Jan Mercl wrote: > > On Wed, Nov 23, 2016 at 4:28 PM T L > wrote: > > > Predeclared functions, including inlined ones, can be viewed as > constants, which have not addresses. > > We can compare variable to constant,

Re: [go-nuts] Why doens't function type support comparision but channel type does?

On Wednesday, November 23, 2016 at 11:47:19 PM UTC+8, Jan Mercl wrote: > > On Wed, Nov 23, 2016 at 4:28 PM T L > wrote: > > > Predeclared functions, including inlined ones, can be viewed as > constants, which have not addresses. > > We can compare variable to constant,

Re: [go-nuts] Why doens't function type support comparision but channel type does?

On Wednesday, November 23, 2016 at 11:28:13 PM UTC+8, T L wrote: > > > > On Wednesday, November 23, 2016 at 11:18:02 PM UTC+8, Jan Mercl wrote: >> >> On Wed, Nov 23, 2016 at 3:30 PM T L wrote: >> >> > Then? >> >> Then there is nothing to compare. If a function is inlined

Re: [go-nuts] Why doens't function type support comparision but channel type does?

On Wed, Nov 23, 2016 at 4:28 PM T L wrote: > Predeclared functions, including inlined ones, can be viewed as constants, which have not addresses. > We can compare variable to constant, right? Wrong. Function pointers, specific Go implementation details aside for now, are

Re: [go-nuts] Re: Why doens't function type support comparision but channel type does?

On Wednesday, November 23, 2016 at 11:11:24 PM UTC+8, Axel Wagner wrote: > > So, even though two functions do completely different things, you still > want to have them equal? And even though two other functions do completely > the same thing, they should be different? > If two functions do

Re: [go-nuts] Thinking OO virtual function in Go

Yes... so every specific animal type implements it's own Output() method, which does the trivial IsA() part, and calls Animal's Output() for the common complicated parts... On Nov 23, 2016 16:35, "Tong Sun" wrote: > Have you noticed the IsA() func call there? > > On Wed,

Re: [go-nuts] Thinking OO virtual function in Go

Oh, I think you might not have notice this request from OP: Please think of the "func Output()" as a very complicated function that I > only want to define *once *at the base level, not to duplicate into each > sub classes. On Wed, Nov 23, 2016 at 10:16 AM, Tong Sun

Re: [go-nuts] Why doens't function type support comparision but channel type does?

On Wed, Nov 23, 2016 at 3:30 PM T L wrote: > Then? Then there is nothing to compare. If a function is inlined then you cannot have a function pointer to it (like in func foo() {}; f := foo). So fully supporting comparing function pointers means disabling inlining of any

Re: [go-nuts] Thinking OO virtual function in Go

Can you make it work on play.golang.org, from this code https://play.golang.org/p/QjCtD9rGpa, according to your plan? On Wed, Nov 23, 2016 at 10:14 AM, Nick Patavalis wrote: > Yes... so every specific animal type implements it's own Output() method, > which does the

Re: [go-nuts] Re: Why doens't function type support comparision but channel type does?

So, even though two functions do completely different things, you still want to have them equal? And even though two other functions do completely the same thing, they should be different? Can you give a good justification of that behavior? And do you really think it won't confuse people like

[go-nuts] Re: Why doens't function type support comparision but channel type does?

On Wednesday, November 23, 2016 at 10:39:01 PM UTC+8, Volker Dobler wrote: > > Am Mittwoch, 23. November 2016 15:30:39 UTC+1 schrieb T L: >> >> >> >> On Wednesday, November 23, 2016 at 9:53:57 PM UTC+8, Volker Dobler wrote: >>> >>> Just one argument out of many: Closures. >>> x := 3 >>> f1 :=

Re: [go-nuts] Re: Why doens't function type support comparision but channel type does?

On Wednesday, November 23, 2016 at 10:35:59 PM UTC+8, Axel Wagner wrote: > > So, your suggestion is, to have functions be comparable, but have the > comparisons always be false (unless compared to nil)? How would that be > useful and *not* completely confusing? e.g. how would that not lead to

Re: [go-nuts] Re: Thinking OO virtual function in Go

On Wed, Nov 23, 2016 at 8:52 AM, Tahir Hashmi wrote: > > I also like the approach suggested by Sebastien Binet. It's really neat in > situations where you can get by without needing to override the base > implementation (e.g. of Shape.Output()). > That it is only a partial solution -- I have a

[go-nuts] Re: Why doens't function type support comparision but channel type does?

Am Mittwoch, 23. November 2016 15:30:39 UTC+1 schrieb T L: > > > > On Wednesday, November 23, 2016 at 9:53:57 PM UTC+8, Volker Dobler wrote: >> >> Just one argument out of many: Closures. >> x := 3 >> f1 := func() int { >> return x >> } >> f2 := func() int { return 3 } >> // Is f1 == f2 ? >> >> x

Re: [go-nuts] Thinking OO virtual function in Go

Have you noticed the IsA() func call there? On Wed, Nov 23, 2016 at 4:05 AM, Nick Patavalis wrote: > Hi, > > In your *second* example, making Output() a method of Animal will work, > since it uses only the members (fields) of Animal, and not the fields of > specific

[go-nuts] Re: Why doens't function type support comparision but channel type does?

On Wednesday, November 23, 2016 at 9:53:57 PM UTC+8, Volker Dobler wrote: > > Just one argument out of many: Closures. > x := 3 > f1 := func() int { > return x > } > f2 := func() int { return 3 } > // Is f1 == f2 ? > > x = 4 > // What now? Still f1 == f2? Or never equal? > > Any bad to think

Re: [go-nuts] Why doens't function type support comparision but channel type does?

On Wednesday, November 23, 2016 at 9:45:56 PM UTC+8, Jan Mercl wrote: > > On Wed, Nov 23, 2016 at 2:40 PM T L > wrote: > > Functions can be inlined. > > -- > > -j > Then? Is there any problem to think no two functions can be equal? -- You received this message because

Re: [go-nuts] Why doens't function type support comparision but channel type does?

If functions are comparable you have to be very careful in defining /when/ they are equal. func f(x int)int {return x+2} func g(x int)int {return x+2} func h(x int)int {return x+1+1} Are f and g equal? f and h? func k() func (int)int { return func(int x)int {x + 1}} Are k() and k() equal? f

[go-nuts] Re: Where should interfaces live?

Great responses. Thanks! I think what it comes down to is there's two main definition/use cases of an interface: - The inheritance-based one that you find in Java and C# where the interface provides an contract into various implementations. The design is typically API-driven and

[go-nuts] Re: Why doens't function type support comparision but channel type does?

Just one argument out of many: Closures. x := 3 f1 := func() int { return x } f2 := func() int { return 3 } // Is f1 == f2 ? x = 4 // What now? Still f1 == f2? Or never equal? V. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe

[go-nuts] Re: Thinking OO virtual function in Go

I've tried to derive how to achieve a) implementation inheritance, followed by b) type substitution and c) enabling dynamic dispatch as in virtual functions in my blog post here: https://tech.t9i.in/2014/01/22/inheritance-semantics-in-go/ I also like the approach suggested by Sebastien Binet.

Re: [go-nuts] Why doens't function type support comparision but channel type does?

On Wed, Nov 23, 2016 at 2:40 PM T L wrote: Functions can be inlined. -- -j -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to

[go-nuts] Why doens't function type support comparision but channel type does?

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Re: [go-nuts] err variable shadowing — is it a bad practice?

I believe vet shadow is known to have issues and is quite picky ;-) Your first one I'd say could be classed as bug as you're clearly declaring n however I'd guess this is due to the for loop as declaring n out of the loop eliminating the short declaration will fix it. This is confirmed by

[go-nuts] err variable shadowing — is it a bad practice?

This is extremely common in go code, vet is being pedantic, -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more

Re: [go-nuts] Thinking OO virtual function in Go

Hi, In your *second* example, making Output() a method of Animal will work, since it uses only the members (fields) of Animal, and not the fields of specific animals (or any behavior that varies between animals). That's why I'm insisting on *real* and *specific* examples, not synthetic ones.