Add a doc comment on the difference between Name and NameRef ast nodes

1 files changed, 16 insertions, 1 deletions

diff --git a/xtask/src/ast_src.rs b/xtask/src/ast_src.rs
index d1e34e299..79e5a608d 100644
--- a/xtask/src/ast_src.rs
+++ b/xtask/src/ast_src.rs
@@ -1522,7 +1522,20 @@ pub(crate) const AST_SRC: AstSrc = AstSrc {
         struct Visibility { T![pub], T![super], T![self], T![crate] }
 
         /// Single identifier.
-        /// // TODO: clarify the difference between Name and NameRef
+        /// Note(@matklad): `Name` is for things that install a new name into the scope,
+        /// `NameRef` is a usage of a name. Most of the time, this definition/reference
+        /// distinction can be determined purely syntactically, ie in
+        /// ```
+        /// fn foo() { foo() }
+        /// ```
+        /// the first foo is `Name`, the second one is `NameRef`.
+        /// The notable exception are patterns, where in
+        /// ``
+        /// let x = 92
+        /// ```
+        /// `x` can be semantically either a name or a name ref, depeding on
+        /// wether there's an `x` constant in scope.
+        /// We use `Name` for patterns, and disambiguate semantically (see `NameClass` in ide_db).
         ///
         /// ```
         /// let ❰ foo ❱ = bar;
@@ -1534,6 +1547,8 @@ pub(crate) const AST_SRC: AstSrc = AstSrc {
         struct Name { T![ident] }
 
         /// Reference to a name.
+        /// See the explanation on the difference between `Name` and `NameRef`
+        /// in `Name` ast node docs.
         ///
         /// ```
         /// let foo = ❰ bar ❱(❰ Baz(❰ bruh ❱) ❱;