Attach parameter list span to function

1 files changed, 14 insertions, 6 deletions

diff --git a/src/syntax/ast.rs b/src/syntax/ast.rs
index 760a6499..59205efb 100644
--- a/src/syntax/ast.rs
+++ b/src/syntax/ast.rs
@@ -1504,12 +1504,8 @@ impl Closure {
     }
 
     /// The parameter bindings.
-    pub fn params(&self) -> impl DoubleEndedIterator<Item = Param> + '_ {
-        self.0
-            .children()
-            .find(|x| x.kind() == SyntaxKind::Params)
-            .map_or([].iter(), |params| params.children())
-            .filter_map(SyntaxNode::cast)
+    pub fn params(&self) -> Params {
+        self.0.cast_first_match().unwrap_or_default()
     }
 
     /// The body of the closure.
@@ -1518,6 +1514,18 @@ impl Closure {
     }
 }
 
+node! {
+    /// A closure's parameters: `(x, y)`.
+    Params
+}
+
+impl Params {
+    /// The parameter bindings.
+    pub fn children(&self) -> impl DoubleEndedIterator<Item = Param> + '_ {
+        self.0.children().filter_map(SyntaxNode::cast)
+    }
+}
+
 /// A parameter to a closure.
 #[derive(Debug, Clone, Hash)]
 pub enum Param {