rust-lang / rust-lang/rust-analyzer

[FR] Code action: expand `||` into inferred closure params/return type at call site (e.g. `|a: u64| -> u32 { … }`)

Open
#20,775 3 comments 1 reaction 0 assignees View on GitHub

Nobody has claimed this yet.

A-assists A-completion C-feature
Dominant language
Rust
Stars
16.9k
Forks
2.2k
Avg merge
1d 12h
Merged PRs (30d)
72

Description

Hello,

Do you think rust-analyzer can have this?

fn main(){
    // I write, and put cursor after ||
    here(||);
    // Then I want to rust-analyzer's code-action convert above line code to bellow code:
    here(|a:u64|-> u32 {
        
    });
}

fn here<F>(a: F)
where
    F: FnOnce(u64) -> u32,
{
    todo!()
}

Thank you.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

The issue names no files, tests, or entry points; begin by locating rust-analyzer's existing code-action handling and support for inferred closure types. Compare the requested Rust example with current behavior, then define completion as a code action that expands the closure with the inferred parameter and return types at the call site.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
devtools
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.