bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

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

Browse source 
`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
commit 6c358c67d4
61 changed files with 278 additions and 333 deletions
Download patch file Download diff file Expand all files Collapse all files

81
compiler/rustc_ast/src/ast.rs
View file

@ -594,7 +594,7 @@ impl Pat {
// In a type expression `_` is an inference variable.
PatKind::Wild => TyKind::Infer,
// An IDENT pattern with no binding mode would be valid as path to a type. E.g. `u32`.
PatKind::Ident(BindingMode::ByValue(Mutability::Not), ident, None) => {
PatKind::Ident(BindingAnnotation::NONE, ident, None) => {
TyKind::Path(None, Path::from_ident(*ident))
}
PatKind::Path(qself, path) => TyKind::Path(qself.clone(), path.clone()),
@ -681,10 +681,43 @@ pub struct PatField {
pub is_placeholder: bool,
}
#[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy)]
pub enum BindingMode {
ByRef(Mutability),
ByValue(Mutability),
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
#[derive(Encodable, Decodable, HashStable_Generic)]
pub enum ByRef {
Yes,
No,
}
impl From<bool> for ByRef {
fn from(b: bool) -> ByRef {
match b {
false => ByRef::No,
true => ByRef::Yes,
}
}
}
/// 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(Clone, Copy, Debug, Eq, PartialEq)]
#[derive(Encodable, Decodable, HashStable_Generic)]
pub struct BindingAnnotation(pub ByRef, pub Mutability);
impl BindingAnnotation {
pub const NONE: Self = Self(ByRef::No, Mutability::Not);
pub const REF: Self = Self(ByRef::Yes, Mutability::Not);
pub const MUT: Self = Self(ByRef::No, Mutability::Mut);
pub const REF_MUT: Self = Self(ByRef::Yes, Mutability::Mut);
pub fn prefix_str(self) -> &'static str {
match self {
Self::NONE => "",
Self::REF => "ref ",
Self::MUT => "mut ",
Self::REF_MUT => "ref mut ",
}
}
}
#[derive(Clone, Encodable, Decodable, Debug)]
@ -713,7 +746,7 @@ pub enum PatKind {
/// or a unit struct/variant pattern, or a const pattern (in the last two cases the third
/// field must be `None`). Disambiguation cannot be done with parser alone, so it happens
/// during name resolution.
Ident(BindingMode, Ident, Option<P<Pat>>),
Ident(BindingAnnotation, Ident, Option<P<Pat>>),
/// A struct or struct variant pattern (e.g., `Variant {x, y, ..}`).
/// The `bool` is `true` in the presence of a `..`.
@ -2228,7 +2261,7 @@ pub type ExplicitSelf = Spanned<SelfKind>;
impl Param {
/// Attempts to cast parameter to `ExplicitSelf`.
pub fn to_self(&self) -> Option<ExplicitSelf> {
if let PatKind::Ident(BindingMode::ByValue(mutbl), ident, _) = self.pat.kind {
if let PatKind::Ident(BindingAnnotation(ByRef::No, mutbl), ident, _) = self.pat.kind {
if ident.name == kw::SelfLower {
return match self.ty.kind {
TyKind::ImplicitSelf => Some(respan(self.pat.span, SelfKind::Value(mutbl))),
@ -2258,23 +2291,10 @@ impl Param {
pub fn from_self(attrs: AttrVec, eself: ExplicitSelf, eself_ident: Ident) -> Param {
let span = eself.span.to(eself_ident.span);
let infer_ty = P(Ty { id: DUMMY_NODE_ID, kind: TyKind::ImplicitSelf, span, tokens: None });
let param = |mutbl, ty| Param {
attrs,
pat: P(Pat {
id: DUMMY_NODE_ID,
kind: PatKind::Ident(BindingMode::ByValue(mutbl), eself_ident, None),
span,
tokens: None,
}),
span,
ty,
id: DUMMY_NODE_ID,
is_placeholder: false,
};
match eself.node {
SelfKind::Explicit(ty, mutbl) => param(mutbl, ty),
SelfKind::Value(mutbl) => param(mutbl, infer_ty),
SelfKind::Region(lt, mutbl) => param(
let (mutbl, ty) = match eself.node {
SelfKind::Explicit(ty, mutbl) => (mutbl, ty),
SelfKind::Value(mutbl) => (mutbl, infer_ty),
SelfKind::Region(lt, mutbl) => (
Mutability::Not,
P(Ty {
id: DUMMY_NODE_ID,
@ -2283,6 +2303,19 @@ impl Param {
tokens: None,
}),
),
};
Param {
attrs,
pat: P(Pat {
id: DUMMY_NODE_ID,
kind: PatKind::Ident(BindingAnnotation(ByRef::No, mutbl), eself_ident, None),
span,
tokens: None,
}),
span,
ty,
id: DUMMY_NODE_ID,
is_placeholder: false,
}
}
}