So, if I get this right, clear on map will result in map length equals to zero, but clear on slice is only a value-zeroing operation and the slice length remains unchanged? They seem like two different operations to me. I don't think that built-in clear function is necessary. It doesn't seem like the function has a good reason to be there.
On Wednesday, July 5, 2023 at 3:54:43 PM UTC+7 Tharaneedharan Vilwanathan wrote: > Hi Axel, > > Okay, that helps! Thanks for the details. > > Regards > dharani > > > On Wed, Jul 5, 2023 at 1:38 AM Axel Wagner <axel.wa...@googlemail.com> > wrote: > >> Hi, >> >> this has come up on the issue as well. Robert Griesemer provided an >> explanation >> <https://github.com/golang/go/issues/56351#issuecomment-1601751291>: >> >> If the argument type (the type of the argument provided to clear) is a >>> type parameter (is of type parameter type), all types in its type set (in >>> the type set of the constraint corresponding to the type parameter) must be >>> maps or slices, and clear performs the operation corresponding to the >>> actual type argument (corresponding to the type of the actual type argument >>> with which the type parameter was instantiated). >> >> >> That is, the sentence is about this situation: >> >> func Clear[T, any, S ~[]T](s S) { >> clear(s) >> } >> func main() { >> Clear(make([]int, 42)) >> } >> >> In this case, the type of s is S, which is a type parameter. So `clear` >> performs the operation corresponding to the type argument - in this example >> []int. >> >> The sentence is a bit confusing (I've seen this question come up four >> times now), so it probably should be clarified a bit. >> >> On Wed, Jul 5, 2023 at 9:06 AM Tharaneedharan Vilwanathan < >> vdha...@gmail.com> wrote: >> >>> Hi All, >>> >>> Go 1.21 introduces a new clear() builtin function. I see this text in >>> https://tip.golang.org/ref/spec#Clear: >>> >>> clear(t) type parameter see below >>> >>> If the argument type is a type parameter >>> <https://tip.golang.org/ref/spec#Type_parameter_declarations>, all >>> types in its type set must be maps or slices, and clear performs the >>> operation corresponding to the actual type argument. >>> >>> I am not able to make sense of it. What does this mean? Any examples on >>> the usage? >>> >>> Appreciate your help. >>> >>> Thanks >>> dharani >>> >>> -- >>> 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...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/golang-nuts/CAN-HoCn99D-m71aJr3DRzCJvk_c7h8OhG2O4wPC-1Wd2ruEYNg%40mail.gmail.com >>> >>> <https://groups.google.com/d/msgid/golang-nuts/CAN-HoCn99D-m71aJr3DRzCJvk_c7h8OhG2O4wPC-1Wd2ruEYNg%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- 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/00e424f1-1a62-4183-8974-9a585960ce7dn%40googlegroups.com.
