Simplify Alt node impl

Author: zharinov

crates/plotnik-lib/src/ast/nodes.rs

@@ -27,7 +27,7 @@ ast_node!(Def, Def);
 ast_node!(Tree, Tree);
 ast_node!(Ref, Ref);
 ast_node!(Str, Str);
-
+ast_node!(Alt, Alt);
 ast_node!(Branch, Branch);
 ast_node!(Seq, Seq);
 ast_node!(Capture, Capture);
@@ -49,54 +49,6 @@ pub enum AltKind {
     Mixed,
 }
 
-/// Alternation node with cached kind.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct Alt {
-    node: SyntaxNode,
-    kind: AltKind,
-}
-
-impl Alt {
-    pub fn cast(node: SyntaxNode) -> Option<Self> {
-        (node.kind() == SyntaxKind::Alt).then(|| {
-            let kind = Self::compute_kind(&node);
-            Self { node, kind }
-        })
-    }
-
-    fn compute_kind(node: &SyntaxNode) -> AltKind {
-        let mut tagged = false;
-        let mut untagged = false;
-
-        for child in node.children().filter(|c| c.kind() == SyntaxKind::Branch) {
-            let has_label = child
-                .children_with_tokens()
-                .filter_map(|it| it.into_token())
-                .any(|t| t.kind() == SyntaxKind::Id);
-
-            if has_label {
-                tagged = true;
-            } else {
-                untagged = true;
-            }
-        }
-
-        match (tagged, untagged) {
-            (true, true) => AltKind::Mixed,
-            (true, false) => AltKind::Tagged,
-            _ => AltKind::Untagged,
-        }
-    }
-
-    pub fn kind(&self) -> AltKind {
-        self.kind
-    }
-
-    pub fn syntax(&self) -> &SyntaxNode {
-        &self.node
-    }
-}
-
 /// Expression: any pattern that can appear in the tree.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum Expr {
@@ -204,12 +156,36 @@ impl Ref {
 }
 
 impl Alt {
+    pub fn kind(&self) -> AltKind {
+        let mut tagged = false;
+        let mut untagged = false;
+
+        for child in self.0.children().filter(|c| c.kind() == SyntaxKind::Branch) {
+            let has_label = child
+                .children_with_tokens()
+                .filter_map(|it| it.into_token())
+                .any(|t| t.kind() == SyntaxKind::Id);
+
+            if has_label {
+                tagged = true;
+            } else {
+                untagged = true;
+            }
+        }
+
+        match (tagged, untagged) {
+            (true, true) => AltKind::Mixed,
+            (true, false) => AltKind::Tagged,
+            _ => AltKind::Untagged,
+        }
+    }
+
     pub fn branches(&self) -> impl Iterator<Item = Branch> + '_ {
-        self.node.children().filter_map(Branch::cast)
+        self.0.children().filter_map(Branch::cast)
     }
 
     pub fn exprs(&self) -> impl Iterator<Item = Expr> + '_ {
-        self.node.children().filter_map(Expr::cast)
+        self.0.children().filter_map(Expr::cast)
     }
 }