Rename LifetimeSyntax variants to lang-team-approved names

Author: shepmaster

compiler/rustc_ast_lowering/src/lib.rs

@@ -1405,7 +1405,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 };
                 let span = self.tcx.sess.source_map().start_point(t.span).shrink_to_hi();
                 let region = Lifetime { ident: Ident::new(kw::UnderscoreLifetime, span), id };
-                (region, LifetimeSyntax::Hidden)
+                (region, LifetimeSyntax::Implicit)
             }
         };
         self.lower_lifetime(&region, LifetimeSource::Reference, syntax)
@@ -1789,7 +1789,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             id,
             Ident::new(kw::UnderscoreLifetime, span),
             LifetimeSource::Path { angle_brackets },
-            LifetimeSyntax::Hidden,
+            LifetimeSyntax::Implicit,
         )
     }
 
@@ -2421,7 +2421,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             Ident::new(kw::UnderscoreLifetime, self.lower_span(span)),
             hir::LifetimeKind::ImplicitObjectLifetimeDefault,
             LifetimeSource::Other,
-            LifetimeSyntax::Hidden,
+            LifetimeSyntax::Implicit,
         );
         debug!("elided_dyn_bound: r={:?}", r);
         self.arena.alloc(r)

compiler/rustc_hir/src/hir.rs

@@ -72,13 +72,13 @@ pub enum LifetimeSource {
 #[derive(Debug, Copy, Clone, PartialEq, Eq, HashStable_Generic)]
 pub enum LifetimeSyntax {
     /// E.g. `&Type`, `ContainsLifetime`
-    Hidden,
+    Implicit,
 
     /// E.g. `&'_ Type`, `ContainsLifetime<'_>`, `impl Trait + '_`, `impl Trait + use<'_>`
-    Anonymous,
+    ExplicitAnonymous,
 
     /// E.g. `&'a Type`, `ContainsLifetime<'a>`, `impl Trait + 'a`, `impl Trait + use<'a>`
-    Named,
+    ExplicitBound,
 }
 
 impl From<Ident> for LifetimeSyntax {
@@ -88,10 +88,10 @@ impl From<Ident> for LifetimeSyntax {
         if name == kw::Empty {
             unreachable!("A lifetime name should never be empty");
         } else if name == kw::UnderscoreLifetime {
-            LifetimeSyntax::Anonymous
+            LifetimeSyntax::ExplicitAnonymous
         } else {
             debug_assert!(name.as_str().starts_with('\''));
-            LifetimeSyntax::Named
+            LifetimeSyntax::ExplicitBound
         }
     }
 }
@@ -102,48 +102,48 @@ impl From<Ident> for LifetimeSyntax {
 ///
 /// ```
 /// #[repr(C)]
-/// struct S<'a>(&'a u32);       // res=Param, name='a, source=Reference, syntax=Named
+/// struct S<'a>(&'a u32);       // res=Param, name='a, source=Reference, syntax=ExplicitBound
 /// unsafe extern "C" {
-///     fn f1(s: S);             // res=Param, name='_, source=Path, syntax=Hidden
-///     fn f2(s: S<'_>);         // res=Param, name='_, source=Path, syntax=Anonymous
-///     fn f3<'a>(s: S<'a>);     // res=Param, name='a, source=Path, syntax=Named
+///     fn f1(s: S);             // res=Param, name='_, source=Path, syntax=Implicit
+///     fn f2(s: S<'_>);         // res=Param, name='_, source=Path, syntax=ExplicitAnonymous
+///     fn f3<'a>(s: S<'a>);     // res=Param, name='a, source=Path, syntax=ExplicitBound
 /// }
 ///
-/// struct St<'a> { x: &'a u32 } // res=Param, name='a, source=Reference, syntax=Named
+/// struct St<'a> { x: &'a u32 } // res=Param, name='a, source=Reference, syntax=ExplicitBound
 /// fn f() {
-///     _ = St { x: &0 };        // res=Infer, name='_, source=Path, syntax=Hidden
-///     _ = St::<'_> { x: &0 };  // res=Infer, name='_, source=Path, syntax=Anonymous
+///     _ = St { x: &0 };        // res=Infer, name='_, source=Path, syntax=Implicit
+///     _ = St::<'_> { x: &0 };  // res=Infer, name='_, source=Path, syntax=ExplicitAnonymous
 /// }
 ///
-/// struct Name<'a>(&'a str);    // res=Param,  name='a, source=Reference, syntax=Named
-/// const A: Name = Name("a");   // res=Static, name='_, source=Path, syntax=Hidden
-/// const B: &str = "";          // res=Static, name='_, source=Reference, syntax=Hidden
-/// static C: &'_ str = "";      // res=Static, name='_, source=Reference, syntax=Anonymous
-/// static D: &'static str = ""; // res=Static, name='static, source=Reference, syntax=Named
+/// struct Name<'a>(&'a str);    // res=Param,  name='a, source=Reference, syntax=ExplicitBound
+/// const A: Name = Name("a");   // res=Static, name='_, source=Path, syntax=Implicit
+/// const B: &str = "";          // res=Static, name='_, source=Reference, syntax=Implicit
+/// static C: &'_ str = "";      // res=Static, name='_, source=Reference, syntax=ExplicitAnonymous
+/// static D: &'static str = ""; // res=Static, name='static, source=Reference, syntax=ExplicitBound
 ///
 /// trait Tr {}
-/// fn tr(_: Box<dyn Tr>) {}     // res=ImplicitObjectLifetimeDefault, name='_, source=Other, syntax=Hidden
+/// fn tr(_: Box<dyn Tr>) {}     // res=ImplicitObjectLifetimeDefault, name='_, source=Other, syntax=Implicit
 ///
 /// fn capture_outlives<'a>() ->
-///     impl FnOnce() + 'a       // res=Param, ident='a, source=OutlivesBound, syntax=Named
+///     impl FnOnce() + 'a       // res=Param, ident='a, source=OutlivesBound, syntax=ExplicitBound
 /// {
 ///     || {}
 /// }
 ///
 /// fn capture_precise<'a>() ->
-///     impl FnOnce() + use<'a>  // res=Param, ident='a, source=PreciseCapturing, syntax=Named
+///     impl FnOnce() + use<'a>  // res=Param, ident='a, source=PreciseCapturing, syntax=ExplicitBound
 /// {
 ///     || {}
 /// }
 ///
 /// // (commented out because these cases trigger errors)
-/// // struct S1<'a>(&'a str);   // res=Param, name='a, source=Reference, syntax=Named
-/// // struct S2(S1);            // res=Error, name='_, source=Path, syntax=Hidden
-/// // struct S3(S1<'_>);        // res=Error, name='_, source=Path, syntax=Anonymous
-/// // struct S4(S1<'a>);        // res=Error, name='a, source=Path, syntax=Named
+/// // struct S1<'a>(&'a str);   // res=Param, name='a, source=Reference, syntax=ExplicitBound
+/// // struct S2(S1);            // res=Error, name='_, source=Path, syntax=Implicit
+/// // struct S3(S1<'_>);        // res=Error, name='_, source=Path, syntax=ExplicitAnonymous
+/// // struct S4(S1<'a>);        // res=Error, name='a, source=Path, syntax=ExplicitBound
 /// ```
 ///
-/// Some combinations that cannot occur are `LifetimeSyntax::Hidden` with
+/// Some combinations that cannot occur are `LifetimeSyntax::Implicit` with
 /// `LifetimeSource::OutlivesBound` or `LifetimeSource::PreciseCapturing`
 /// — there's no way to "elide" these lifetimes.
 #[derive(Debug, Copy, Clone, HashStable_Generic)]
@@ -287,12 +287,8 @@ impl Lifetime {
         self.ident.name == kw::UnderscoreLifetime
     }
 
-    pub fn is_syntactically_hidden(&self) -> bool {
-        matches!(self.syntax, LifetimeSyntax::Hidden)
-    }
-
-    pub fn is_syntactically_anonymous(&self) -> bool {
-        matches!(self.syntax, LifetimeSyntax::Anonymous)
+    pub fn is_implicit(&self) -> bool {
+        matches!(self.syntax, LifetimeSyntax::Implicit)
     }
 
     pub fn is_static(&self) -> bool {
@@ -307,28 +303,28 @@ impl Lifetime {
 
         match (self.syntax, self.source) {
             // The user wrote `'a` or `'_`.
-            (Named | Anonymous, _) => (self.ident.span, format!("{new_lifetime}")),
+            (ExplicitBound | ExplicitAnonymous, _) => (self.ident.span, format!("{new_lifetime}")),
 
             // The user wrote `Path<T>`, and omitted the `'_,`.
-            (Hidden, Path { angle_brackets: AngleBrackets::Full }) => {
+            (Implicit, Path { angle_brackets: AngleBrackets::Full }) => {
                 (self.ident.span, format!("{new_lifetime}, "))
             }
 
             // The user wrote `Path<>`, and omitted the `'_`..
-            (Hidden, Path { angle_brackets: AngleBrackets::Empty }) => {
+            (Implicit, Path { angle_brackets: AngleBrackets::Empty }) => {
                 (self.ident.span, format!("{new_lifetime}"))
             }
 
             // The user wrote `Path` and omitted the `<'_>`.
-            (Hidden, Path { angle_brackets: AngleBrackets::Missing }) => {
+            (Implicit, Path { angle_brackets: AngleBrackets::Missing }) => {
                 (self.ident.span.shrink_to_hi(), format!("<{new_lifetime}>"))
             }
 
             // The user wrote `&type` or `&mut type`.
-            (Hidden, Reference) => (self.ident.span, format!("{new_lifetime} ")),
+            (Implicit, Reference) => (self.ident.span, format!("{new_lifetime} ")),
 
-            (Hidden, source) => {
-                unreachable!("can't suggest for a hidden lifetime of {source:?}")
+            (Implicit, source) => {
+                unreachable!("can't suggest for a implicit lifetime of {source:?}")
             }
         }
     }

compiler/rustc_hir/src/hir/tests.rs

@@ -55,7 +55,7 @@ fn trait_object_roundtrips_impl(syntax: TraitObjectSyntax) {
         ident: Ident::new(sym::name, DUMMY_SP),
         kind: LifetimeKind::Static,
         source: LifetimeSource::Other,
-        syntax: LifetimeSyntax::Hidden,
+        syntax: LifetimeSyntax::Implicit,
     };
     let unambig = TyKind::TraitObject::<'_, ()>(&[], TaggedRef::new(&lt, syntax));
     let unambig_to_ambig = unsafe { std::mem::transmute::<_, TyKind<'_, AmbigArg>>(unambig) };

compiler/rustc_trait_selection/src/errors.rs

@@ -587,7 +587,7 @@ impl Subdiagnostic for AddLifetimeParamsSuggestion<'_> {
                                         matches!(
                                             arg,
                                             hir::GenericArg::Lifetime(lifetime)
-                                                if lifetime.is_syntactically_hidden()
+                                                if lifetime.is_implicit()
                                         )
                                     }) {
                                         self.suggestions.push((