rust-lang / rust-lang/rustfmt

Special-case quote! macro

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#3,406 8 comments 7 reactions 0 assignees View on GitHub

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A-macros C-feature-request P-low
Dominant language
Rust
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Forks
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Avg merge
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Merged PRs (30d)
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Description

quote! is fairly popular for code generation, and more often than not its argument could be passed and formatted as valid Rust code.

The only thing that prevents that from happening right now is parser stumbling on #name substitutions, but if they're temporarily replaced with regular identifiers as we already do for macro definitions, this shouldn't be a problem.

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First steps

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  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

Start by tracing how rustfmt parses quote! arguments and how macro definitions temporarily replace substitutions such as #name. Confirm the parser failure with representative valid Rust code, then verify that quote! arguments containing these substitutions are formatted successfully without changing their meaning.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
tooling
Issue type
Feature
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
38/100

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