[evantbyrne]

Is it possible that some of the mismatch in how people view Go's type system is due to experiences differing from writing applications vs writing libraries? I personally find some of the repetition in Go code to be tolerable when writing web applications and CLI tools, but a real issue for the composability of libraries with different purposes. Going back to the database toolkit example, the query builder can easily return a result type, but what if I also want to handle validation of input before the query and then later return a HTTP response? Well to chain a result type end-to-end in Go requires it to have knowledge of all the different types/interfaces that it could map to, which I believe is way too broad of a responsibility for one type, even though all of those features feel as though they could very naturally chain together and reduce down to a single error. These kinds of type limitations effectively force Go libraries to live on their own islands where they don't compose with one another.

[liampulles]

The "Go-ithic" way to write a library is to be strict with its API and place the onus on the consumer to do the work to map to and from it. So if I understand your example correctly (I might not), then it would be totally acceptable and in fact preferable for a Go codebase to map between the validator, then the query builder, and then the http response. Its preferable because I want libraries to have a thin API and be focused on doing one thing well, and I also want to have it clearly presented to me how I am mapping to and from an external dependency.

Another way of putting is that the Go philosophy is not to abstract details away or try and hide them, its to make the actual control flow of the program as plain and obvious as possible.

[evantbyrne]

I understand that is the Go philosophy. I care more about what is practical than dogmatic. It seems clear to me as a complex library author that the type system leads to way too much glue code, which is expensive to write and maintain.

[liampulles]

As a Go developer of a few years now, I don't find it that way. I've found it to be very easy to write the glue code, because its largely the same as other glue code, and I find it easy to maintain because the plain control flow makes finding bugs easy. But perhaps the takeaway here is that, because Go certainly is opinionated, its a way of doing business that works for some and not others. And that's cool.