filter VS tokio

Here’s Rob Pike’s (one of the original Go designers) attempt to “see what the hubbub is all about”: https://github.com/robpike/filter

I find the language really solid but asking on r/golang is quite an adventure. It's extremely distant from go's spirit, the grammar is even more rich than Rust. Typical example: let, run, with, apply, and also - they all practically do the same but with a different scope of this and return value. Just looking at the flow API can get your head spinning. To illustrate how much it's completely the opposite of Go, see how Rob Pike pokes fun at map/filter and tells people they should not use it . I guess you can't force all developers to adhere to this mental model, but that's about it, but that's about it, technical arguments are irrelevant except for extremely niche concerns about memory and startup time

I mean sure, let's praise the ergonomics of channels and the reliability of maps. As for datastructures, we already have datastructures at home . They just work fine. Nobody needs more than that because rob pike told us so

Go will never have a map/filter syntax, to the point rob pike even makes fun of it , do you really want to use it for that kind of domain ?

Also since generators are mentioned I recently came across this rob pike moment, he implemented a reduce function that takes and returns all interface{} types and uses reflection to check if the call is valid at runtime - that's the most typical Go that can ever be written in 40 lines - all that to make the point that it's useless. Such a great spirit. https://github.com/robpike/filter

A few points that stood out to me: error handling in Go is generally pretty good. It's much more performant compared to throwing exceptions and the high frequency of error handling helps a lot with debugging and avoiding unexpected errors. What you've described as "poor OOP'ish" is partly true, yes Go does poor OOP, because it doesn't try to do OOP. The language favours composition over inheritance. Strongly applying OOP concepts in Go is simply not using the language in its intended way. For implicit interfaces, it's completely fair that you don't like them, but it's not a disadvantage of the language. I for one find implicit interfaces very intuitive and feel it's the right way for it to be done. No function overloading and lack of ternary operations is absolutely intentional, both of these are overcome by writing more expressive code, which is not a bad thing. Similarly with no built in map/filter/find, these can be achieved using for-loops. Reference https://github.com/robpike/filter for Rob Pike's implementation of filter, stating in the readme that there's not much use for it and to just use for-loops instead. Last thing, enums are expressed using iota: https://go.dev/ref/spec#Iota

> I didn't get that desire for purity that you gleaned from it.

'Folks who develop an allergic reaction to "big balls of mutable state without sum types" tend to gravitate towards languages that gives them control over mutability, lifetimes, and lets them build abstractions.'

This mutability argument is present throughout the article. Seems like nothing sans Rust or niche functional languages is enough.

> Nil pointer exceptions, for example, don't have to exist anymore..

The language most notorious for those is Java due to almost everything being passed via a nullable reference. When everything can be nullable, how can you know where to check for it? Go addresses this to an extent by explicitly separating pointers from values. Values are the default and cannot be nil, so the opportunity for null dereferences is greatly diminished. It's not a perfect solution, but it's not nothing either.

> and yet they do in Go because they couldn't be bothered to add sum types.

Damn those lazy Go devs!

> Its type system is barely a step above a dynamic language.

Turns out even a basic type system is a huge improvement over none. Just being able to restrict values to concrete types goes a long way.

> You have to write the same imperative looping code over and over because Rob Pike would rather just use a for loop than something mildly expressive like map or filter (https://github.com/robpike/filter).

There are arguments to be made either way, but I definitely agree generics (along with iterators) should have been there since day 1.

> Every function that does meaningful work is littered with if err != nil { return err }.

One big positive of this that I don't see in other languages is every `return` in a function must be on the start of a line. That is, every single exit path of a function is easily findable by visually scanning

Being able to control nondeterminism is particularly useful for testing and debugging. This allows creating reproducible test environments, as well as discrete-event simulation for faster-than-real-time simulation of time delays. For example, Cardano uses a simulation environment for the IO monad that closely follows core Haskell packages; Sui has a simulator based on madsim that provides an API-compatible replacement for the Tokio runtime and intercepts various POSIX API calls in order to enforce determinism. Both allow running the same code in production as in the simulator for testing.

tokio / hyper / toml / serde / serde_json / json5 / console

tokio - An asynchronous runtime for Rust

3. Tokio

The AWS SDK makes use of the async capabilities in the Tokio library. So when you see async in front of a fn that function is capable of executing asynchronously.

Petar is also looking at implementing concurrency the way it is in Go to have a fully functional virtual machine as it is in the spec. This would likely attract more external contributors to developing the VM. One advantage of Rust is that, with the concurrency model, there is already an extensive library called Tokio which he can use. Petar stresses that this isn’t easy, but he believes it’s achievable, at least as a research topic around determinism and concurrency.

Another thing to point out is that async is a thing in Rust. I'm not going to begin to dive into this paradigm in this article, but know it's handled by the awesome Tokio framework.

So I started by using Tokio, a popular async runtime. The docs and samples helped me get a simple outbound TCP connection working. The Rust async book also had a lot of good explanations, both practical and digging into the details of what a runtime does.

Regarding the quote:

> The Original Sin of Rust async programming is making it multi-threaded by default. If premature optimization is the root of all evil, this is the mother of all premature optimizations, and it curses all your code with the unholy Send + 'static, or worse yet Send + Sync + 'static, which just kills all the joy of actually writing Rust.

Agree about the melodramatic tone. I also don't think removing the Send + Sync really makes that big a difference. It's the 'static that bothers me the most. I want scoped concurrency. Something like <https://github.com/tokio-rs/tokio/issues/2596>.

Another thing I really hate about Rust async right now is the poor instrumentation. I'm having a production problem at work right now in which some tasks just get stuck. I wish I could do the equivalent of `gdb; thread apply all bt`. Looking forward to <https://github.com/tokio-rs/tokio/issues/5638> landing at least. It exists right now but is experimental and in my experience sometimes panics. I'm actually writing a PR today to at least use the experimental version on SIGTERM to see what's going on, on the theory that if it crashes oh well, we're shutting down anyway.

Neither of these complaints would be addressed by taking away work stealing. In fact, I could keep doing down my list, and taking away work stealing wouldn't really help with much of anything.

The PHP <-> Rust bindings are provided by https://github.com/Nicelocal/ext-php-rs/ (our fork of https://github.com/davidcole1340/ext-php-rs with a bunch of UX improvements :).

php-tokio's integrates the https://revolt.run event loop with the https://tokio.rs event loop; async functionality is provided by the two event loops, in combination with PHP fibers through revolt's suspension API (I could've directly used the PHP Fiber API to provide coroutine suspension, but it was a tad easier with revolt's suspension API (https://revolt.run/fibers), since it also handles the base case of suspension in the main fiber).