src: address a bunch of clippy::pedantic lints

src/ast.rs

@@ -276,7 +276,7 @@ impl<A: Annotation> Default for Expr<A> {
 }
 
 impl<A: Annotation> Expr<A> {
-    pub fn anno(self, annotation: A) -> Anno<Expr<A>, A> {
+    pub const fn anno(self, annotation: A) -> Anno<Expr<A>, A> {
         Anno(self, annotation)
     }
 
@@ -292,15 +292,15 @@ impl<A: Annotation> Expr<A> {
         Self::Op(Op::Do, exprs)
     }
 
-    pub fn is_place(&self) -> bool {
+    pub const fn is_place(&self) -> bool {
         matches!(
             self,
-            Self::Id(_) | Self::Op(Op::Index, _) | Self::Op(Op::Dot, _) | Self::Op(Op::Deref, _)
+            Self::Id(_) | Self::Op(Op::Index | Op::Dot | Op::Deref, _)
         )
     }
 
     #[allow(clippy::type_complexity)]
-    pub fn as_slice(&self) -> Option<(Op, &[Anno<Expr<A>, A>])> {
+    pub const fn as_slice(&self) -> Option<(Op, &[Anno<Expr<A>, A>])> {
         match self {
             Expr::Op(op, args) => Some((*op, args.as_slice())),
             _ => None,