[chimeracoder]

It's funny that OP uses Twitter as the case study at the end. I wrote what was then the first (and think still the only) Go Twitter client library that works with v1.1 of Twitter's API[0]. It implements automatic rate-limiting/throttling behind the scenes, and it returns values of concrete types (not interfaces) ready for immediate use.

Keep in mind that, were I to write this again today from scratch, there are a number of things I would do differently (since I started it as a relative beginner expanded on it as my familiarity with Go developed, it's grown to be a bit over-engineered in places). But I still think it's a worthwhile example in this discussion.

For concurrency, I wouldn't say that what OP is trying to do is going to be easy in any language, because OAuth in general kind of sucks[1] the Twitter API itself has a number of quirks that make it cumbersome in general, irrespective of language[2]. That said, Go was by far the easiest to work with here, because channels allowed me to abstract the pagination and the rate-limiting in a way that it would be invisible to all callers, but "magically" handled behind the scenes.

Without going into too much detail, I can see that the way OP has designed his code looks a bit cumbersome. That said, while it's a reasonable way of approaching it, I don't think it's actually the best approach in Go given the language's idioms.

One other thing I want to draw attention to is the use of the general-purpose function for issuing a GET request to Twitter, and how that is shared among the various functions that use it to return values of varying, but known, types.

I don't want to use the word "generic" here because people expect a certain thing when they hear that word, but I will say that this function is (A) general-purpose, and (B) type-safe - it involves no type assertions, and the functions all return concrete types instead if interface{}.

[0] https://github.com/ChimeraCoder/anaconda/

[1] Don't get me started on this

[2] I've written client libraries for Twitter in a few different languages, so I actually have a reasonable point of reference on this - at one point, it was my personal "hello world" for testing out a new language.

[dkarapetyan]

I'm curious to see this general purpose function of yours. You are also addressing a different point than the article. The main point is that patterns like parallel map are impossible to implement in Go in a type-safe manner. This is a valid complaint depending on what is meant by type-safe and at this point the arguments for/against Go usually devolve into name calling and matters of culture. If you could factor out all that general purpose functionality from your code base, e.g. the rate-limiting and other things, and turn it into a re-usable library then that would be an entirely different matter. Whether that would qualify according to the author's definition of type-safe is another matter.

[jordwest]

It looks like this is the function: https://github.com/ChimeraCoder/anaconda/blob/master/twitter...

This looks like a good example of interface{} used correctly - the consumer of the apiGet function passes in their strongly typed object, which then is handed in to json.Decode. No type safety is lost from the perspective of the consumer, while the json.Decode can operate on any struct type.

Sure this addresses a different issue, but for all the complaints about interface{} I think this is a good use-case.