json VS hyper

Oh wow. So serde_json doesn't roundtrip floats by default, it uses some imprecise faster algorithm https://github.com/serde-rs/json/issues/707

Good thing there's msgpack I guess.

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

Serde JSON, an extension of the serde crate that enables the serialization and deserialization of Rust structs.

To serialize and deserialize data, we'll employ the popular serde crate along with serde_json. This will allow us to easily convert between Rust types and JSON when working with API requests and responses. For async operations we'll use the Rust futures crate.

From the Cargo.toml file above, we can see that the Perseus version at the time of publication is 0.4.2 and has the following dependencies that are common to both the engine side (server-side) and client side of a Perseus application: sycamore, serde, and serde_json.

serde_json

Number parsing uses a fairly naive but uses a lossless algorithm in musli-json. In serde_json they use a fork of lexical I haven't wrapped my head around. I wanted something simple to start with.

Your best best would be to use an enum. Either your own or something like the one from serde_json depending on what you are trying to do.

Don't do that if you care about memory usage. In your toy program, I wouldn't be surprised if memory usage was a lot better if you used Box instead. (even if it doesn't look like it, you can handle almost all the use cases of serde_json::Value with it, often not much less convenient)

> If you are equally picky and constrain yourself to parts of the ecosystem which care about binary size, you still have more options and can avoid size issues.

What's an example of this for, say, libcurl? On my system it has a tiny number of recursive dependencies, around a dozen. [0] Furthermore if I want to write a C program that uses libcurl I have to download zero bytes of data ... because it's a shared library that is already installed on my system, since so many programs already use it.

I don't really know the appropriate comparison for Rust. reqwest seems roughly comparable, but it's an HTTP client library, and not a general purpose network client like curl. Obviously curl can do a lot more. Even the list of direct dependencies for reqwest is quite long [1], and it's built on top of another http library [2] that has its own long list of dependencies, a list that includes tokio, no small library itself.

In terms of final binary size, the installed size of the curl package on my system, which includes both the command line tool and development dependencies for libcurl, is 1875.03 KiB.

[0] I'm excluding the dependency on the ca-certificates package, since this only provides the certificate chain for TLS and lots of programs rely on it.

[1] https://crates.io/crates/reqwest/0.11.24/dependencies

[2] https://crates.io/crates/hyper/0.14.28/dependencies

hyper-based HTTP server generating JSON responses. Written in Rust.

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

Using Rust here was immensely helpful, using libraries made by the community like https://github.com/hyperium/hyper really powered up the development of Signway, so glad to see this kind of awesome crates made public. Hope that it continues to be like that despite the current controversies.

- Discord sends a slightly weird request by specifying content length (a bug in hyper we've not yet upgraded to fix, https://github.com/hyperium/hyper/commit/fb90d30c02d8f7cdc9a643597d5c4ca7a123f3dd)