[go-nuts] multiple rangefunc iterators: restart?
I've been playing with with rangefunc experiment, with help from https://go.dev/wiki/RangefuncExperiment and the possible idioms that might come out of it (https://blog.perfects.engineering/go_range_over_funcs is a good read). One somewhat eccentric use of nested iterators I built in the past in python was turning an SQL widerows or domain aggregate result into a set of nested objects, so one could use the results in something like the following way: for p in people: for c in p.cars: for t in c.tickets: print("person {} in car {} got ticket {}", p, c, t) While I was able to get a very janky version of this type of behaviour with https://go.dev/play/p/gFUcKNSrbMV?v=gotip this only has an iterator on the left hand side and series of nested structs through slices. My attempts to use more iterators (for cars and tickets) fails as these of course stop after the first set of cars and tickets respectively have been yielded. I realise this is a contrived example, but I wonder if there might be more general cases where iterators could be stopped and restarted. (The docs to iter.Pull suggest next() and stop() are non-resettable also.) Perhaps there could be hidden new iter.Seq constructors in the container for when the cars and tickets iterators are exhausted...hmm... I'd be grateful for any thoughts about this casual and hypothetical case, although I guess it could be helpful for something like retrieving nested data from an sql cursor efficiently. Cheers Rory That code above turns: a a1 a2 b1 b2 b3 c1 c2 c3 a a1 a2 b1 b2 b3 c4 c5 c6 a a1 a2 b1 b2 b3 c7 c8 c9 a a1 a2 b4 b5 b6 c10 c11 c12 d d1 d2 e1 e2 e3 f1 f2 f3 d d1 d2 e1 e2 e3 f4 f5 f6 g g1 g2 h1 h2 h3 i1 i2 i3 into: [a a1 a2] > [b1 b2 b3] > > [c1 c2 c3] > > [c4 c5 c6] > > [c7 c8 c9] > [b4 b5 b6] > > [c10 c11 c12] [d d1 d2] > [e1 e2 e3] > > [f1 f2 f3] > > [f4 f5 f6] [g g1 g2] > [h1 h2 h3] > > [i1 i2 i3] called like this: for a := range collection.Iter() { // iter.Seq fmt.Println(a.r) for _, b := range a.s {// slice -- could be iter.Seq? fmt.Println("> ", b.r) for _, c := range b.s {// slice -- could be iter.Seq? fmt.Println("> > ", c.r) } } } -- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/Zk94CqLUJ6fJjmuA%40campbell-lange.net.
Re: [go-nuts] Re: Call the .net dlls into the golang
"try building at the command line" That's your clue. You'll most likely get a meaningful error message on stderr, which your IDE is hiding. On Thursday 23 May 2024 at 13:47:10 UTC+1 Pavan Kumar A R wrote: > Hello , > > I am try to call the c program in the golang , but i am getting the issue > . please see the error message : > package main > > go list failed to return CompiledGoFiles. This may indicate failure to > perform cgo processing; try building at the command line. See > https://golang.org/issue/38990.go list > View Problem (Alt+F8) > > > //#cgo LDFLAGS: -L. -llibCWrapper-win64 -Wl,-rpath,. > //#include "ealApiLib.h" > > import "C" > import "fmt" > > func main() { > > result := C.Connect("192.168.1.1") > > fmt.Println("connection success" + result) > > } > > > > On Thursday 23 May 2024 at 02:53:12 UTC+5:30 peterGo wrote: > >> cgo command >> https://pkg.go.dev/cmd/cgo >> Cgo enables the creation of Go packages that call C code. >> >> On Wednesday, May 22, 2024 at 4:41:13 PM UTC-4 Carla Pfaff wrote: >> >>> Yes, you can call C functions from Go, it's called Cgo: >>> https://go.dev/blog/cgo >>> >>> On Wednesday 22 May 2024 at 18:04:19 UTC+2 Pavan Kumar A R wrote: >>> > Okay, it's possible to call the C program to Golang. Because I also > have the C platform dlls and the C platform dlls we using in the cross > platform mono and in the mono internally call the.net dlls function , > can I use the C program dlls in Golang? > -- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/21db8561-176e-4857-a904-8bda3c226ab3n%40googlegroups.com.
Re: [go-nuts] Re: Call the .net dlls into the golang
Hello , I am try to call the c program in the golang , but i am getting the issue . please see the error message : package main go list failed to return CompiledGoFiles. This may indicate failure to perform cgo processing; try building at the command line. See https://golang.org/issue/38990.go list View Problem (Alt+F8) //#cgo LDFLAGS: -L. -llibCWrapper-win64 -Wl,-rpath,. //#include "ealApiLib.h" import "C" import "fmt" func main() { result := C.Connect("192.168.1.1") fmt.Println("connection success" + result) } On Thursday 23 May 2024 at 02:53:12 UTC+5:30 peterGo wrote: > cgo command > https://pkg.go.dev/cmd/cgo > Cgo enables the creation of Go packages that call C code. > > On Wednesday, May 22, 2024 at 4:41:13 PM UTC-4 Carla Pfaff wrote: > >> Yes, you can call C functions from Go, it's called Cgo: >> https://go.dev/blog/cgo >> >> On Wednesday 22 May 2024 at 18:04:19 UTC+2 Pavan Kumar A R wrote: >> >>> Okay, it's possible to call the C program to Golang. Because I also have the C platform dlls and the C platform dlls we using in the cross platform mono and in the mono internally call the.net dlls function , can I use the C program dlls in Golang? >>> -- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/d8665110-07f3-4f0d-8e14-49900cd4b6abn%40googlegroups.com.