From ab68fa3b05df46bffe21b41ddb67878bc01f26dd Mon Sep 17 00:00:00 2001
From: alexion <contact@alexion.dev>
Date: Sat, 19 Sep 2026 20:41:14 -0400
Subject: [PATCH] refactor(xatu): move binding filters into rules

---
 src/xatu/ast.rs                       | 12 ++++-
 src/xatu/parser.rs                    | 77 ++++++++++++---------------
 src/xatu/rules/manual_inherit.rs      |  5 +-
 src/xatu/rules/manual_inherit_from.rs | 10 +++-
 4 files changed, 57 insertions(+), 47 deletions(-)

diff --git a/src/xatu/ast.rs b/src/xatu/ast.rs
index 64de2c6..a12e30e 100644
--- a/src/xatu/ast.rs
+++ b/src/xatu/ast.rs
@@ -33,14 +33,21 @@ pub enum NodeData {
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Binding {
-    pub name: Ident,
+    pub path: Vec<Attr>,
     pub value: Expr,
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Attr {
+    Ident(Ident),
+    Other,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum Expr {
     Ident(Ident),
     Select(Box<Select>),
+    Other,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -51,7 +58,8 @@ pub struct Ident {
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Select {
     pub receiver: Expr,
-    pub attrs: Vec<Ident>,
+    pub path: Vec<Attr>,
+    pub has_default: bool,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
diff --git a/src/xatu/parser.rs b/src/xatu/parser.rs
index 8159954..51340d7 100644
--- a/src/xatu/parser.rs
+++ b/src/xatu/parser.rs
@@ -44,7 +44,7 @@ fn convert_node(node: rnix::SyntaxNode) -> Option<ast::Node> {
 fn convert_binding(node: rnix::SyntaxNode) -> Option<ast::Node> {
     let binding = rnix::ast::AttrpathValue::cast(node)?;
     let range = binding.syntax().text_range().into();
-    let data = binding.try_into().ok()?;
+    let data = binding.into();
 
     Some(ast::Node {
         range,
@@ -52,38 +52,35 @@ fn convert_binding(node: rnix::SyntaxNode) -> Option<ast::Node> {
     })
 }
 
-impl TryFrom<rnix::ast::AttrpathValue> for ast::Binding {
-    type Error = ();
-
-    fn try_from(binding: rnix::ast::AttrpathValue) -> Result<Self, Self::Error> {
-        let mut attrs = binding.attrpath().ok_or(())?.attrs();
-        let rnix::ast::Attr::Ident(name) = attrs.next().ok_or(())? else {
-            return Err(());
-        };
-        if attrs.next().is_some() {
-            return Err(());
+impl From<rnix::ast::AttrpathValue> for ast::Binding {
+    fn from(binding: rnix::ast::AttrpathValue) -> Self {
+        Self {
+            path: binding
+                .attrpath()
+                .into_iter()
+                .flat_map(|path| path.attrs())
+                .map(Into::into)
+                .collect(),
+            value: binding.value().map(Into::into).unwrap_or(ast::Expr::Other),
         }
-
-        let value = binding.value().ok_or(())?;
-        if matches!(&value, rnix::ast::Expr::Select(select) if select.or_token().is_some()) {
-            return Err(());
-        }
-
-        Ok(Self {
-            name: name.into(),
-            value: value.try_into()?,
-        })
     }
 }
 
-impl TryFrom<rnix::ast::Expr> for ast::Expr {
-    type Error = ();
+impl From<rnix::ast::Attr> for ast::Attr {
+    fn from(attr: rnix::ast::Attr) -> Self {
+        match attr {
+            rnix::ast::Attr::Ident(ident) => Self::Ident(ident.into()),
+            _ => Self::Other,
+        }
+    }
+}
 
-    fn try_from(expr: rnix::ast::Expr) -> Result<Self, Self::Error> {
+impl From<rnix::ast::Expr> for ast::Expr {
+    fn from(expr: rnix::ast::Expr) -> Self {
         match expr {
-            rnix::ast::Expr::Ident(ident) => Ok(Self::Ident(ident.into())),
-            rnix::ast::Expr::Select(select) => Ok(Self::Select(Box::new(select.try_into()?))),
-            _ => Err(()),
+            rnix::ast::Expr::Ident(ident) => Self::Ident(ident.into()),
+            rnix::ast::Expr::Select(select) => Self::Select(Box::new(select.into())),
+            _ => Self::Other,
         }
     }
 }
@@ -96,22 +93,18 @@ impl From<rnix::ast::Ident> for ast::Ident {
     }
 }
 
-impl TryFrom<rnix::ast::Select> for ast::Select {
-    type Error = ();
-
-    fn try_from(select: rnix::ast::Select) -> Result<Self, Self::Error> {
-        Ok(Self {
-            receiver: select.expr().ok_or(())?.try_into()?,
-            attrs: select
+impl From<rnix::ast::Select> for ast::Select {
+    fn from(select: rnix::ast::Select) -> Self {
+        Self {
+            receiver: select.expr().map(Into::into).unwrap_or(ast::Expr::Other),
+            path: select
                 .attrpath()
-                .ok_or(())?
-                .attrs()
-                .map(|attr| match attr {
-                    rnix::ast::Attr::Ident(ident) => Ok(ident.into()),
-                    _ => Err(()),
-                })
-                .collect::<Result<Vec<_>, _>>()?,
-        })
+                .into_iter()
+                .flat_map(|path| path.attrs())
+                .map(Into::into)
+                .collect(),
+            has_default: select.or_token().is_some(),
+        }
     }
 }
 
diff --git a/src/xatu/rules/manual_inherit.rs b/src/xatu/rules/manual_inherit.rs
index 58cc6c0..338903a 100644
--- a/src/xatu/rules/manual_inherit.rs
+++ b/src/xatu/rules/manual_inherit.rs
@@ -13,10 +13,13 @@ impl NodeRule for ManualInherit {
     }
 
     fn check(binding: &Self::Node) -> Option<&'static str> {
+        let [ast::Attr::Ident(name)] = binding.path.as_slice() else {
+            return None;
+        };
         let ast::Expr::Ident(value) = &binding.value else {
             return None;
         };
 
-        (binding.name == *value).then_some("Use `inherit` for this binding")
+        (name == value).then_some("Use `inherit` for this binding")
     }
 }
diff --git a/src/xatu/rules/manual_inherit_from.rs b/src/xatu/rules/manual_inherit_from.rs
index 5cc4b80..9a62f69 100644
--- a/src/xatu/rules/manual_inherit_from.rs
+++ b/src/xatu/rules/manual_inherit_from.rs
@@ -13,16 +13,22 @@ impl NodeRule for ManualInheritFrom {
     }
 
     fn check(binding: &Self::Node) -> Option<&'static str> {
+        let [ast::Attr::Ident(name)] = binding.path.as_slice() else {
+            return None;
+        };
         let ast::Expr::Select(select) = &binding.value else {
             return None;
         };
         let ast::Expr::Ident(_) = &select.receiver else {
             return None;
         };
-        let [selected] = select.attrs.as_slice() else {
+        let [ast::Attr::Ident(selected)] = select.path.as_slice() else {
             return None;
         };
+        if select.has_default {
+            return None;
+        }
 
-        (binding.name == *selected).then_some("Use `inherit (source)` for this binding")
+        (name == selected).then_some("Use `inherit (source)` for this binding")
     }
 }