Represent lifetimes as Names instead of Idents #12451
Conversation
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FWIW, do we really want lifetimes to be non-hygienic? i.e. should macro_rules! foo ( ($t: ty) => { fn foo<'a>(a: &'a int, b: $t) { ... } })
foo!(&'a int)be valid? (This is particularly important if we ever get macros being able to expand to methods (#4621), in which case the above with impl<'a> Foo<'a> {
foo!(&'a int) // meant to be Foo's 'a.
}) (Sorry to be annoying about hygiene...) |
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That said, reverting this patch shouldn't be particularly hard if we do implement hygiene for them later... |
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I'm inclined to agree with @huonw here: As his example illustrates, a macro can expand into a I do not understand the motivation outlined in the description on #7743: "This will allow them to be safely compared without fear of runtime-fail." Is this just talking about when writing In any case I'd prefer runtime-fail over having active footguns that are hidden by lack of hygiene. @jbclements can you elaborate? |
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If a decision is made, I can always revert this patch. One caveat is since #12338 has turned lifetime renaming on, we may hit ast.rs#L67. |
… fields. After PR rust-lang#12451 landed, lifetimes carry a `Name` instead of an `Ident`. But that PR did not change the field names in `ast.rs` to `name` instead of the prevous `ident`. This impedes hacking on the code, since you are using `foo.ident` in a content expecting a `Name` half the time. We may or may not revert PR rust-lang#12451 in the future (for unrelated reasons). But in the mean time, here are two changes to ease working with the existing code: * Adding the `ast::LifetimeName` alias eases swapping in a newtype struct when hacking, or changing the alias to `Ident` in the future. * Renaming the `ident` fields of type `LifetimeName` to be `name` instead makes the code look much saner.
feat: Support `$$` in macros. The implementation mirrors what `rustc` currently does [1]. Part of rust-lang#11952. \[1]: https://github.com/rust-lang/rust/blob/0595ea1d12cf745e0a672d05341429ecb0917e66/compiler/rustc_expand/src/mbe/quoted.rs#L230-L241
new restriction lint: `integer_division_remainder_used` Fixes rust-lang/rust-clippy#12391 Introduces a restriction lint which disallows the use of `/` and `%` operators on any `Int` or `Uint` types (i.e., any that use the default `Div` or `Rem` trait implementations). Custom implementations of these traits are ignored. ---- changelog: Add new restriction lint [`integer_division_remainder_used`]
Closes #7743.