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Merged
fmease merged 1 commit into from
Apr 23, 2026
Merged

Change order of impl restrictions #34

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2 changes: 1 addition & 1 deletion src/lib/ast/item.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -293,10 +293,10 @@ pub struct TraitAliasItem<'src> {

#[derive(Default, Debug)]
pub struct TraitItemModifiers<'src> {
pub impl_restriction: Option<Path<'src, NoGenericArgs>>,
pub const_: Const,
pub safety: Safety,
pub auto: Auto,
pub impl_restriction: Option<Path<'src, NoGenericArgs>>,
}

#[derive(Default, Debug)]
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8 changes: 4 additions & 4 deletions src/lib/fmter/item.rs
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Expand Up @@ -575,16 +575,16 @@ impl Fmt for (ast::TraitItem<'_>, Vec<ast::Attr<'_, ast::InnerAttrStyle>>) {

impl Fmt for TrailingSpace<ast::TraitItemModifiers<'_>> {
fn fmt(self, cx: &mut Cx<'_>) {
let Self(ast::TraitItemModifiers { const_, safety, auto, impl_restriction }) = self;
let Self(ast::TraitItemModifiers { impl_restriction, const_, safety, auto }) = self;

const_.trailing_space().fmt(cx);
safety.trailing_space().fmt(cx);
auto.trailing_space().fmt(cx);
if let Some(path) = impl_restriction {
fmt!(cx, "impl");
Restriction(path).fmt(cx);
fmt!(cx, " ");
}
const_.trailing_space().fmt(cx);
safety.trailing_space().fmt(cx);
auto.trailing_space().fmt(cx);
}
}

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38 changes: 21 additions & 17 deletions src/lib/parser/item.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -232,6 +232,14 @@ impl<'src> Parser<'_, '_, 'src> {
&mut [mut ref mut qualifiers @ .., Qualifier::Trait] => {
let mut modifiers = ast::TraitItemModifiers::default();

(modifiers.impl_restriction, qualifiers) = match qualifiers {
[Qualifier::ImplRestriction(path), qualifiers @ ..] => {
self.feature_no_span_fixme(Feature::impl_restriction);
let Ok(path) = path else { return Err(()) };
(Some(mem::replace(path, ast::Path { segs: Vec::new() })), qualifiers)
}
_ => (None, qualifiers),
};
(modifiers.const_, qualifiers) = Qualifier::strip_const(qualifiers);
if let ast::Const::Yes = modifiers.const_ {
self.feature_no_span_fixme(Feature::const_trait_impl);
Expand All @@ -244,14 +252,6 @@ impl<'src> Parser<'_, '_, 'src> {
}
_ => (ast::Auto::No, qualifiers),
};
(modifiers.impl_restriction, qualifiers) = match qualifiers {
[Qualifier::ImplRestriction(path), qualifiers @ ..] => {
self.feature_no_span_fixme(Feature::impl_restriction);
let Ok(path) = path else { return Err(()) };
(Some(mem::replace(path, ast::Path { segs: Vec::new() })), qualifiers)
}
_ => (None, qualifiers),
};
if !qualifiers.is_empty() {
self.error(Error::InvalidItemPrefix(start.until(self.token.span)));
}
Expand Down Expand Up @@ -352,7 +352,11 @@ impl<'src> Parser<'_, '_, 'src> {
TokenKind::Impl => {
self.advance();

if let Some(path) = self.parse_restriction(Some(TokenKind::Trait)) {
// We disqualify sequences like `impl(crate) {` which should be
// interpreted as impl blocks instead.
if let Some(path) =
self.parse_restriction(|kind| kind != TokenKind::OpenCurlyBracket)
{
yield (Qualifier::ImplRestriction(Box::new(path)), self.token.kind);
continue;
}
Expand Down Expand Up @@ -819,7 +823,11 @@ impl<'src> Parser<'_, '_, 'src> {

self.parse(TokenKind::Semicolon)?;

let ast::TraitItemModifiers { const_, safety, auto, impl_restriction } = modifiers;
let ast::TraitItemModifiers { impl_restriction, const_, safety, auto } = modifiers;

if impl_restriction.is_some() {
self.error(Error::ImplRestrictedTraitAlias);
}

match safety {
ast::Safety::Inherited => {}
Expand All @@ -831,10 +839,6 @@ impl<'src> Parser<'_, '_, 'src> {
ast::Auto::No => {}
}

if impl_restriction.is_some() {
self.error(Error::ImplRestrictedTraitAlias);
}

Ok(ast::ItemKind::TraitAlias(Box::new(ast::TraitAliasItem {
const_,
binder,
Expand Down Expand Up @@ -1103,7 +1107,7 @@ impl<'src> Parser<'_, '_, 'src> {
return Ok(ast::Visibility::Inherited);
}

if let Some(path) = self.parse_restriction(None) {
if let Some(path) = self.parse_restriction(|_| true) {
return Ok(ast::Visibility::Restricted(path?));
}

Expand All @@ -1118,7 +1122,7 @@ impl<'src> Parser<'_, '_, 'src> {

fn parse_restriction(
&mut self,
disambiguator: Option<TokenKind>,
may_follow: fn(TokenKind) -> bool,
) -> Option<Result<ast::Path<'src, ast::NoGenericArgs>>> {
enum Herald {
In,
Expand All @@ -1130,7 +1134,7 @@ impl<'src> Parser<'_, '_, 'src> {
&& let Some(herald) = match token.kind {
TokenKind::Crate | TokenKind::Super | TokenKind::SelfLower
if let TokenKind::CloseRoundBracket = self.peek(2).kind
&& disambiguator.is_none_or(|t| self.peek(3).kind == t) =>
&& may_follow(self.peek(3).kind) =>
{
Some(Herald::CrateSuperSelf(token.span))
}
Expand Down
14 changes: 10 additions & 4 deletions src/lib/parser/test/item.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -167,8 +167,6 @@ async safe extern fn f() {}
async safe fn f() {}
async unsafe extern fn f() {}
async unsafe fn f() {}
auto impl(crate) trait Trait {}
auto impl(in crate) trait Trait {}
auto trait Trait {}
const F: () = ();
const async fn f() {}
Expand Down Expand Up @@ -210,8 +208,13 @@ gen extern fn f() {}
gen fn f() {}
gen unsafe fn f() {}
impl !Trait for () {}
impl (crate) {}
impl Trait for () {}
impl const Trait for () {}
impl(crate) auto trait Trait {}
impl(in crate) auto trait Trait {}
impl(self) trait Trait {}
impl(super) const trait Trait {}
pub const extern "C" fn f() {}
pub const fn f() {}
pub const unsafe extern "C" fn f() {}
Expand Down Expand Up @@ -274,8 +277,6 @@ async safe extern fn f() {}
async safe fn f() {}
async unsafe extern fn f() {}
async unsafe fn f() {}
auto impl(crate) trait Trait {}
auto impl(in crate) trait Trait {}
auto trait Trait {}
const F: () = ();
const async fn f() {}
Expand Down Expand Up @@ -317,8 +318,13 @@ gen extern fn f() {}
gen fn f() {}
gen unsafe fn f() {}
impl !Trait for () {}
impl (crate) {}
impl Trait for () {}
impl const Trait for () {}
impl(crate) auto trait Trait {}
impl(in crate) auto trait Trait {}
impl(self) trait Trait {}
impl(super) const trait Trait {}
pub const extern "C" fn f() {}
pub const fn f() {}
pub const unsafe extern "C" fn f() {}
Expand Down