On Sat, Dec 3, 2022 at 8:47 PM Diogo Baeder <diogobae...@gmail.com> wrote:
> Hi there, sorry for weighting in so late in the game, but I just started > again to learn Go and was thinking why the language still doesn't have a > tuple type. > > Now, imagine this scenario: I have a web application which has to access a > webservice that responds with JSON payloads; These payloads are a list of > values, where each value is a smaller list like '[20220101, 1.234, "New > York"]'. And these smaller lists follow the same type sequence: int64, > float64, string. Suppose that I want to filter those values and send a > response to the client, with the data structure unchanged (same format and > types). Today, it doesn't seem to be possible to do that in Go, unless I do > some dirty hack like decoding to '[]any' and then cast to the other types, > and then hack again to put these values in the response to the client. > What you described above is a struct. > > I totally understand the reasoning for preferring the usage of structs for > heterogeneous data (and I myself do prefer them, they're much more powerful > in general), but there's real world data that's available like in the > example above, and we just can't go on changing them at their sources. I > might be mistaken (please let me know if it's the case), but it seems like > Go is missing an opportunity to interoperate with what's a fundamental data > structure in many other languages (Python, Rust etc). I'm having a lot of > fun learning to use the language, and would be happy to see this feature > being implemented at the core. > In general, you can implement most tuple functionality using []any. However, when dealing with unpredictable data structures like an unknown JSON document, third-party libraries might be better suited than a map[string]any. When you have a tuple like that, you have to "discover" the type of each variable and parse it to do any nontrivial processing. You can't really unmarshal a string from a JSON document and expect to get a date in the tuple. My current work is on the interoperability of heterogeneous data, so for XML documents we use DOM libraries, for JSON documents we wrote https://github.com/bserdar/jsonom, etc. > > (Maybe what I said above is total BS, I acknowledge that since I'm an > almost complete ignorant in the language) > > Cheers! > > On Thursday, April 19, 2018 at 1:03:55 PM UTC-3 Louki Sumirniy wrote: > >> Multiple return values. They do kinda exist in a declarative form of >> sorts, in the type signature, this sets the number and sequence and types >> of return values. You could even make functions accept them as also input >> values, I think, but I don't think it works exactly like this. I'm not a >> fan of these things because of how you have to nominate variables or _ and >> type inference will make these new variables, if you := into whatever the >> return was. >> >> I'm not sure what the correct word is for them. Untyped in the same way >> that literals can be multiple types (especially integers) but singular in >> their literal form. >> >> >> On Thursday, 19 April 2018 16:06:42 UTC+3, Jan Mercl wrote: >>> >>> On Thu, Apr 19, 2018 at 2:51 PM Louki Sumirniy <louki.sumir...@gmail.com> >>> wrote: >>> >>> > Sorry for the self-promotion but it was relevant in that I was working >>> on how to tidy up the readability of my code and needed multiple returns >>> and simple untyped tuples were really not nearly as convenient as using a >>> type struct. >>> >>> I have no idea what you mean by 'untyped tuples' because Go does not >>> have tuples, or at least not as a well defined thing. I can only guess if >>> you're trying to implement tuples in Go with an array, slice or a struct, >>> ...? To add to my confusion, Go functions can have as many return values as >>> one wishes just fine, ie. I obviously do not even understand what problem >>> you're trying to solve. Sorry. >>> >>> >>> -- >>> >>> -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 golang-nuts+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/8e728e0f-341d-4340-a868-aac028dfc443n%40googlegroups.com > <https://groups.google.com/d/msgid/golang-nuts/8e728e0f-341d-4340-a868-aac028dfc443n%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/CAMV2Rqq%2BDmRDuqcxW-DF%2ByDqTrAu%3DNv51wLWZsx2ERiYEv%3DZ1w%40mail.gmail.com.
