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Implement &pin const self and &pin mut self sugars

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This commit is contained in:
Frank King
2025-01-19 23:30:58 +08:00
parent 4559163ccb
commit cb7d687e96
10 changed files with 304 additions and 13 deletions
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21
compiler/rustc_ast/src/ast.rs
View File

@@ -2641,6 +2641,8 @@ pub enum SelfKind {
Value(Mutability),
/// `&'lt self`, `&'lt mut self`
Region(Option<Lifetime>, Mutability),
/// `&'lt pin const self`, `&'lt pin mut self`
Pinned(Option<Lifetime>, Mutability),
/// `self: TYPE`, `mut self: TYPE`
Explicit(P<Ty>, Mutability),
}
@@ -2650,6 +2652,8 @@ impl SelfKind {
match self {
SelfKind::Region(None, mutbl) => mutbl.ref_prefix_str().to_string(),
SelfKind::Region(Some(lt), mutbl) => format!("&{lt} {}", mutbl.prefix_str()),
SelfKind::Pinned(None, mutbl) => format!("&pin {}", mutbl.ptr_str()),
SelfKind::Pinned(Some(lt), mutbl) => format!("&{lt} pin {}", mutbl.ptr_str()),
SelfKind::Value(_) | SelfKind::Explicit(_, _) => {
unreachable!("if we had an explicit self, we wouldn't be here")
}
@@ -2666,11 +2670,13 @@ impl Param {
if ident.name == kw::SelfLower {
return match self.ty.kind {
TyKind::ImplicitSelf => Some(respan(self.pat.span, SelfKind::Value(mutbl))),
TyKind::Ref(lt, MutTy { ref ty, mutbl })
| TyKind::PinnedRef(lt, MutTy { ref ty, mutbl })
TyKind::Ref(lt, MutTy { ref ty, mutbl }) if ty.kind.is_implicit_self() => {
Some(respan(self.pat.span, SelfKind::Region(lt, mutbl)))
}
TyKind::PinnedRef(lt, MutTy { ref ty, mutbl })
if ty.kind.is_implicit_self() =>
{
Some(respan(self.pat.span, SelfKind::Region(lt, mutbl)))
Some(respan(self.pat.span, SelfKind::Pinned(lt, mutbl)))
}
_ => Some(respan(
self.pat.span.to(self.ty.span),
@@ -2712,6 +2718,15 @@ impl Param {
tokens: None,
}),
),
SelfKind::Pinned(lt, mutbl) => (
mutbl,
P(Ty {
id: DUMMY_NODE_ID,
kind: TyKind::PinnedRef(lt, MutTy { ty: infer_ty, mutbl }),
span,
tokens: None,
}),
),
};
Param {
attrs,

7
compiler/rustc_ast_pretty/src/pprust/state.rs
View File

@@ -1783,6 +1783,13 @@ impl<'a> State<'a> {
self.print_mutability(*m, false);
self.word("self")
}
SelfKind::Pinned(lt, m) => {
self.word("&");
self.print_opt_lifetime(lt);
self.word("pin ");
self.print_mutability(*m, true);
self.word("self")
}
SelfKind::Explicit(typ, m) => {
self.print_mutability(*m, false);
self.word("self");

45
compiler/rustc_parse/src/parser/item.rs
View File

@@ -2959,9 +2959,20 @@ impl<'a> Parser<'a> {
this.is_keyword_ahead(n, &[kw::SelfLower])
&& this.look_ahead(n + 1, |t| t != &token::PathSep)
};
// Is `pin const self` `n` tokens ahead?
let is_isolated_pin_const_self = |this: &Self, n| {
this.look_ahead(n, |token| token.is_ident_named(sym::pin))
&& this.is_keyword_ahead(n + 1, &[kw::Const])
&& is_isolated_self(this, n + 2)
};
// Is `mut self` `n` tokens ahead?
let is_isolated_mut_self =
|this: &Self, n| this.is_keyword_ahead(n, &[kw::Mut]) && is_isolated_self(this, n + 1);
// Is `pin mut self` `n` tokens ahead?
let is_isolated_pin_mut_self = |this: &Self, n| {
this.look_ahead(n, |token| token.is_ident_named(sym::pin))
&& is_isolated_mut_self(this, n + 1)
};
// Parse `self` or `self: TYPE`. We already know the current token is `self`.
let parse_self_possibly_typed = |this: &mut Self, m| {
let eself_ident = expect_self_ident(this);
@@ -3021,6 +3032,20 @@ impl<'a> Parser<'a> {
self.bump();
self.bump();
SelfKind::Region(None, Mutability::Mut)
} else if is_isolated_pin_const_self(self, 1) {
// `&pin const self`
self.bump(); // &
self.psess.gated_spans.gate(sym::pin_ergonomics, self.token.span);
self.bump(); // pin
self.bump(); // const
SelfKind::Pinned(None, Mutability::Not)
} else if is_isolated_pin_mut_self(self, 1) {
// `&pin mut self`
self.bump(); // &
self.psess.gated_spans.gate(sym::pin_ergonomics, self.token.span);
self.bump(); // pin
self.bump(); // mut
SelfKind::Pinned(None, Mutability::Mut)
} else if self.look_ahead(1, |t| t.is_lifetime()) && is_isolated_self(self, 2) {
// `&'lt self`
self.bump();
@@ -3032,6 +3057,26 @@ impl<'a> Parser<'a> {
let lt = self.expect_lifetime();
self.bump();
SelfKind::Region(Some(lt), Mutability::Mut)
} else if self.look_ahead(1, |t| t.is_lifetime())
&& is_isolated_pin_const_self(self, 2)
{
// `&'lt pin const self`
self.bump(); // &
let lt = self.expect_lifetime();
self.psess.gated_spans.gate(sym::pin_ergonomics, self.token.span);
self.bump(); // pin
self.bump(); // const
SelfKind::Pinned(Some(lt), Mutability::Not)
} else if self.look_ahead(1, |t| t.is_lifetime())
&& is_isolated_pin_mut_self(self, 2)
{
// `&'lt pin mut self`
self.bump(); // &
let lt = self.expect_lifetime();
self.psess.gated_spans.gate(sym::pin_ergonomics, self.token.span);
self.bump(); // pin
self.bump(); // mut
SelfKind::Pinned(Some(lt), Mutability::Mut)
} else {
// `&not_self`
return Ok(None);