Auto merge of rust-lang#14711 - Veykril:highlight-captures, r=Veykril

feat: Highlight closure captures when cursor is on pipe or move keyword

This runs into the same issue on vscode as exit points for `->`, where highlights are only triggered on identifiers, rust-lang/rust-analyzer#9395

Though putting the cursor on `move` should at least work.

Author: bors

crates/hir-ty/src/infer/closure.rs

@@ -118,6 +118,7 @@ pub(crate) struct HirPlace {
     pub(crate) local: BindingId,
     pub(crate) projections: Vec<ProjectionElem<Infallible, Ty>>,
 }
+
 impl HirPlace {
     fn ty(&self, ctx: &mut InferenceContext<'_>) -> Ty {
         let mut ty = ctx.table.resolve_completely(ctx.result[self.local].clone());
@@ -161,6 +162,10 @@ pub struct CapturedItem {
 }
 
 impl CapturedItem {
+    pub fn local(&self) -> BindingId {
+        self.place.local
+    }
+
     pub fn display_kind(&self) -> &'static str {
         match self.kind {
             CaptureKind::ByRef(k) => match k {

crates/hir/src/lib.rs

@@ -3209,11 +3209,11 @@ impl Closure {
         self.clone().as_ty().display(db).with_closure_style(ClosureStyle::ImplFn).to_string()
     }
 
-    pub fn captured_items(&self, db: &dyn HirDatabase) -> Vec<hir_ty::CapturedItem> {
+    pub fn captured_items(&self, db: &dyn HirDatabase) -> Vec<ClosureCapture> {
         let owner = db.lookup_intern_closure((self.id).into()).0;
         let infer = &db.infer(owner);
         let info = infer.closure_info(&self.id);
-        info.0.clone()
+        info.0.iter().cloned().map(|capture| ClosureCapture { owner, capture }).collect()
     }
 
     pub fn fn_trait(&self, db: &dyn HirDatabase) -> FnTrait {
@@ -3224,6 +3224,26 @@ impl Closure {
     }
 }
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct ClosureCapture {
+    owner: DefWithBodyId,
+    capture: hir_ty::CapturedItem,
+}
+
+impl ClosureCapture {
+    pub fn local(&self) -> Local {
+        Local { parent: self.owner, binding_id: self.capture.local() }
+    }
+
+    pub fn display_kind(&self) -> &'static str {
+        self.capture.display_kind()
+    }
+
+    pub fn display_place(&self, owner: ClosureId, db: &dyn HirDatabase) -> String {
+        self.capture.display_place(owner, db)
+    }
+}
+
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct Type {
     env: Arc<TraitEnvironment>,