I haven't really used gob much, so unfortunately I can't *really* help you. But one thing to note is that you can dump the content of the buffer and see that it doesn't actually contain the name of the type you are encoding: https://play.golang.org/p/R8HB6RP8kS0 I agree that from the documentation, it seems to me that it *should* and I can't really see what this is doing wrong. And I agree that this probably shouldn't panic, but instead return an error. But given that the encoded bytes don't contain the name of the concrete struct, there is no way the decoder can know where you want to put it, without giving it the correct type.
On Thu, Aug 15, 2019 at 9:22 AM Jochen Voss <jochen.v...@gmail.com> wrote: > Dear Marcin, > > My aim is to unmarshal into an interface variable, without having to know > in advance which concrete type I'm receiving (the actual interface has > several possible implementations, and gob data comes in over a network > connection). So, while your code avoids the panic, it does not solve my > problem. > > Many thanks, > Jochen > > On Wednesday, 14 August 2019 22:12:54 UTC+1, Marcin Romaszewicz wrote: >> >> Here you go: >> https://play.golang.org/p/_cPmaSxRatC >> >> You want to unmarshal into &A, not into &Duck >> >> This means: >> var duck2 A >> >> not: >> var duck2 Duck >> >> On Wed, Aug 14, 2019 at 8:46 AM Jochen Voss <joche...@gmail.com> wrote: >> >>> Hello, >>> >>> I'm trying to read gob-encoded data into a variable of interface type. >>> In simple cases, this works for me, but when I use a custom encoding >>> via MarshalBinary() and UnmarshalBinary() methods, my code keeps crashing, >>> with the error message >>> >>> panic: interface conversion: interface is nil, not >>> encoding.BinaryUnmarshaler >>> >>> Example: >>> >>> - The code at https://play.golang.org/p/y8nWNhObUwb, letting gob do the >>> en-/decoding works. >>> >>> - The very similar code at https://play.golang.org/p/-zS7QjEJg9x, which >>> uses MarshalBinary() and UnmarshalBinary() crashes with the panic shown >>> above. >>> >>> What am I doing wrong? >>> >>> [I asked the same question at >>> https://stackoverflow.com/questions/57485698/, with no answers so far] >>> >>> Many thanks, >>> Jochen >>> >>> -- >>> 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 golan...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/golang-nuts/b19c51bc-524c-4292-915b-fc00e9289052%40googlegroups.com >>> <https://groups.google.com/d/msgid/golang-nuts/b19c51bc-524c-4292-915b-fc00e9289052%40googlegroups.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/042b28c0-d768-4cba-94cf-159cf4231818%40googlegroups.com > <https://groups.google.com/d/msgid/golang-nuts/042b28c0-d768-4cba-94cf-159cf4231818%40googlegroups.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/CAEkBMfFp567QVvMy4iOmYfuWzQFdbNovNAJXGu%2Bk_%3DcDKm7yBg%40mail.gmail.com.
