hickory VS quote

Hopefully you've got a cute little Shakespearean Email Bot working and now you're itching to schedule this bot to send you a quote every day at 9:00am. To accomplish this install hickory:

A surprising source of slow compile times can be declarative macros in Rust [0].

I believe the core of the problem is that it has to reparse the code to pattern match for the macro.

One egregious patter is tt-munchers [1] where your macro is implemented recursively, requiring it to reparse the source on each call [2].

In one of my projects, someone decided to wrap a lot of core functions in simple macros (ie nt tt-munchers) to simplify the signatures. Unlike most macros which are used occasionally and have small inputs, this was a lot of input. When I refactored the code, I suspect dropping the macros is the reason CI times were cut in half and a clean `cargo check` went from 3s to 0.5s.

[0]: https://nnethercote.github.io/2022/04/12/how-to-speed-up-the...

[1]: https://veykril.github.io/tlborm/decl-macros/patterns/tt-mun...

[2]: https://github.com/dtolnay/quote/blob/31c3be473d0457e29c4f47...

In the build.rs, call your code generation function (probably in a separate crate added in build-dependencies). This function will read your input files, and use something like quote to generate code.

Or you can pair them with crates like syn, and quote for quasi-quoting, and then it's easy to make transformations on the AST of Rust input code. A lot of libraries do this for code-generation and hiding away a lot of complexity (example wasm-bindgen).