Auto merge of #101241 - camsteffen:refactor-binding-annotations, r=cjgillot

`BindingAnnotation` refactor

* `ast::BindingMode` is deleted and replaced with `hir::BindingAnnotation` (which is moved to `ast`)
* `BindingAnnotation` is changed from an enum to a tuple struct e.g. `BindingAnnotation(ByRef::No, Mutability::Mut)`
* Associated constants added for convenience `BindingAnnotation::{NONE, REF, MUT, REF_MUT}`

One goal is to make it more clear that `BindingAnnotation` merely represents syntax `ref mut` and not the actual binding mode. This was especially confusing since we had `ast::BindingMode`->`hir::BindingAnnotation`->`thir::BindingMode`.

I wish there were more symmetry between `ByRef` and `Mutability` (variant) naming (maybe `Mutable::Yes`?), and I also don't love how long the name `BindingAnnotation` is, but this seems like the best compromise. Ideas welcome.
This commit is contained in:
bors
2022-09-06 03:16:29 +00:00
61 changed files with 278 additions and 333 deletions

View File

@@ -7,7 +7,7 @@ use crate::LangItem;
use rustc_ast as ast;
use rustc_ast::util::parser::ExprPrecedence;
use rustc_ast::{Attribute, FloatTy, IntTy, Label, LitKind, TraitObjectSyntax, UintTy};
pub use rustc_ast::{BorrowKind, ImplPolarity, IsAuto};
pub use rustc_ast::{BindingAnnotation, BorrowKind, ByRef, ImplPolarity, IsAuto};
pub use rustc_ast::{CaptureBy, Movability, Mutability};
use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
use rustc_data_structures::fingerprint::Fingerprint;
@@ -1044,30 +1044,6 @@ pub struct PatField<'hir> {
pub span: Span,
}
/// Explicit binding annotations given in the HIR for a binding. Note
/// that this is not the final binding *mode* that we infer after type
/// inference.
#[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
pub enum BindingAnnotation {
/// No binding annotation given: this means that the final binding mode
/// will depend on whether we have skipped through a `&` reference
/// when matching. For example, the `x` in `Some(x)` will have binding
/// mode `None`; if you do `let Some(x) = &Some(22)`, it will
/// ultimately be inferred to be by-reference.
///
/// Note that implicit reference skipping is not implemented yet (#42640).
Unannotated,
/// Annotated with `mut x` -- could be either ref or not, similar to `None`.
Mutable,
/// Annotated as `ref`, like `ref x`
Ref,
/// Annotated as `ref mut x`.
RefMut,
}
#[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
pub enum RangeEnd {
Included,