rayon-rs/rayon

A `#[parallelized]` attribute

Open

#553 opened on Mar 12, 2018

View on GitHub
 (10 comments) (38 reactions) (0 assignees)Rust (450 forks)batch import
enhancementhelp wanted

Repository metrics

Stars
 (9,410 stars)
PR merge metrics
 (Avg merge 9m) (2 merged PRs in 30d)

Description

Once custom attributes are stable, I think it would be great to have an attribute that transforms a for loop into a parallel iterator for_each call:

#[parallelized]
for x in 0..100 {
    println!("{}", x);
}

Equivalent to:

(0..100).into_par_iter().for_each(|x| println!("{}", x));

This would be analogous to futures-await's #[async] attribute, which generates a for loop that processes a Stream.

The one nit would be that early returns would be a mistake, hopefully a compiler error, and you would probably want to do what you can to catch them while expanding the attribute.

Contributor guide

Research direction
Implement a procedural macro attribute `#[parallelized]` that transforms a for loop into a call to `into par iter().for each()`. Study the Rust proc macro documentation and Rayon's API. Ensure that early returns are caught and produce a compiler error.
Tech stack
rust
Domain
backend
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Rustprocedural macros
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65