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| author | Nicholas Nethercote <n.nethercote@gmail.com> | 2024-12-17 11:46:23 +1100 |
|---|---|---|
| committer | Nicholas Nethercote <n.nethercote@gmail.com> | 2024-12-18 20:21:03 +1100 |
| commit | 6de550cc68d5eb7dc5013987c87859e2f589ac12 (patch) | |
| tree | 7bf96b3a91307032c9167b0ed3240eff23ec5f4e /compiler | |
| parent | ed5b91abc8591fbbc4337cc14b484eb3ed5a2955 (diff) | |
| download | rust-6de550cc68d5eb7dc5013987c87859e2f589ac12.tar.gz rust-6de550cc68d5eb7dc5013987c87859e2f589ac12.zip | |
Improve comments on `Keywords`.
In particular, clarify which predicates apply to which keywords.
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_span/src/symbol.rs | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs index 11441854a76..a7ff0576f92 100644 --- a/compiler/rustc_span/src/symbol.rs +++ b/compiler/rustc_span/src/symbol.rs @@ -20,18 +20,26 @@ mod tests; // The proc macro code for this is in `compiler/rustc_macros/src/symbols.rs`. symbols! { - // If you modify this list, adjust any relevant `Symbol::{is,can_be}_*` functions and + // This list includes things that are definitely keywords (e.g. `if`), + // a few things that are definitely not keywords (e.g. the empty symbol, + // `{{root}}`) and things where there is disagreement between people and/or + // documents (such as the Rust Reference) about whether it is a keyword + // (e.g. `_`). + // + // If you modify this list, adjust any relevant `Symbol::{is,can_be}_*` predicates and // `used_keywords`. // But this should rarely be necessary if the keywords are kept in alphabetic order. Keywords { // Special reserved identifiers used internally for elided lifetimes, // unnamed method parameters, crate root module, error recovery etc. + // Matching predicates: `is_any_keyword`, `is_special`/`is_reserved` Empty: "", PathRoot: "{{root}}", DollarCrate: "$crate", Underscore: "_", // Keywords that are used in stable Rust. + // Matching predicates: `is_any_keyword`, `is_used_keyword_always`/`is_reserved` As: "as", Break: "break", Const: "const", @@ -69,6 +77,7 @@ symbols! { While: "while", // Keywords that are used in unstable Rust or reserved for future use. + // Matching predicates: `is_any_keyword`, `is_unused_keyword_always`/`is_reserved` Abstract: "abstract", Become: "become", Box: "box", @@ -83,19 +92,25 @@ symbols! { Yield: "yield", // Edition-specific keywords that are used in stable Rust. + // Matching predicates: `is_any_keyword`, `is_used_keyword_conditional`/`is_reserved` (if + // the edition suffices) Async: "async", // >= 2018 Edition only Await: "await", // >= 2018 Edition only Dyn: "dyn", // >= 2018 Edition only // Edition-specific keywords that are used in unstable Rust or reserved for future use. + // Matching predicates: `is_any_keyword`, `is_unused_keyword_conditional`/`is_reserved` (if + // the edition suffices) Gen: "gen", // >= 2024 Edition only Try: "try", // >= 2018 Edition only - // Special lifetime names + // "Lifetime keywords": regular keywords with a leading `'`. + // Matching predicates: `is_any_keyword` UnderscoreLifetime: "'_", StaticLifetime: "'static", // Weak keywords, have special meaning only in specific contexts. + // Matching predicates: `is_any_keyword` Auto: "auto", Builtin: "builtin", Catch: "catch", |