quote
todo_by
quote | todo_by | |
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3 | 2 | |
1,232 | 117 | |
- | - | |
7.3 | 3.2 | |
about 1 month ago | 5 days ago | |
Rust | Rust | |
Apache License 2.0 | MIT License |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
quote
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C++ vs. Rust Build Times
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...
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Is generating code from JSON a good macro use case?
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.
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Any good resources for learning Rust macros?
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).
todo_by
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todo_by: Compile-time lifetimes for comments.
Let me know what you think, and if you think you can help out with an issue that affects library authors, please share your insights!
What are some alternatives?
cargo-expand - Subcommand to show result of macro expansion
syn - Parser for Rust source code
proc-macro-workshop - Learn to write Rust procedural macros [Rust Latam conference, Montevideo Uruguay, March 2019]
Constime - Zig's comptime for Rust. Mostly something to play around with until more stuff is `const` fn.
Bytecode - A Rust proc-macro crate which derives functions to compile and parse back enums and structs to and from a bytecode representation
todo-or-die - TODOs you cannot forget!
component-keycloak - Commodore Component for Keycloak
darling - A Rust proc-macro attribute parser
maybe-async-rs - A procedure macro to unify SYNC and ASYNC implementation for downstream application/crates
rust-fsm - Finite state machine framework for Rust with readable specifications
hickory - Command line tool for scheduling Python scripts