cl-ast: Give Impl/ImplKind some love

cl-ast/src/ast_impl.rs

@@ -236,8 +236,20 @@ mod display {
         }
     }
     impl Display for Impl {
-        fn fmt(&self, _f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            todo!("impl Display for Impl")
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            let Self { target, body } = self;
+            write!(f, "impl {target} ")?;
+            delimit(|f| body.fmt(f), BRACES)(f)
+        }
+    }
+    impl Display for ImplKind {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            match self {
+                ImplKind::Type(t) => t.fmt(f),
+                ImplKind::Trait { impl_trait, for_type } => {
+                    write!(f, "{impl_trait} for {for_type}")
+                }
+            }
         }
     }
 
@@ -551,6 +563,15 @@ mod convert {
             Identifier(value.as_ref().into())
         }
     }
+    impl<T: AsRef<str>> From<T> for PathPart {
+        fn from(value: T) -> Self {
+            match value.as_ref() {
+                "Self" => PathPart::SelfKw,
+                "super" => PathPart::SuperKw,
+                ident => PathPart::Ident(ident.into()),
+            }
+        }
+    }
 
     macro impl_from ($(impl From for $T:ty {$($from:ty => $to:expr),*$(,)?})*) {$($(
         impl From<$from> for $T {

cl-ast/src/lib.rs

@@ -205,14 +205,14 @@ pub enum VariantKind {
 /// Sub-[items](Item) (associated functions, etc.) for a [Ty]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Impl {
-    pub target: Ty,
-    pub body: Vec<Item>,
+    pub target: ImplKind,
+    pub body: File,
 }
 
 // TODO: `impl` Trait for <Target> { }
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum ImplKind {
-    Type(Box<Ty>),
+    Type(Ty),
     Trait { impl_trait: Path, for_type: Box<Ty> },
 }
 

cl-repl/examples/yaml.rs

@@ -312,6 +312,16 @@ pub mod yamlify {
             y.key("Impl").pair("target", target).pair("body", body);
         }
     }
+    impl Yamlify for ImplKind {
+        fn yaml(&self, y: &mut Yamler) {
+            match self {
+                ImplKind::Type(t) => y.value(t),
+                ImplKind::Trait { impl_trait, for_type } => {
+                    y.pair("trait", impl_trait).pair("for_type", for_type)
+                }
+            };
+        }
+    }
     impl Yamlify for Block {
         fn yaml(&self, y: &mut Yamler) {
             let Self { stmts } = self;