Follow some clippy suggestions and other misc cleanup.

src/ast.rs

@@ -143,13 +143,10 @@ impl Ast {
         expd_form: ::std::rc::Rc<::form::Form>,
     ) -> Option<::util::mbe::EnvMBE<Ast>>
     {
-        match self {
-            Node(ref f, ref parts, _) => {
-                if f == &expd_form {
-                    return Some(parts.clone());
-                }
+        if let Node(ref f, ref parts, _) = self {
+            if f == &expd_form {
+                return Some(parts.clone());
             }
-            _ => {}
         }
         None
     }

src/ast_walk.rs

@@ -82,8 +82,6 @@ impl<Elt: WalkElt> Clo<Elt> {
         let o_renaming =
             o_different_env.keyed_map_borrow_f(&mut |name, _| VariableReference(name.freshen()));
 
-        // if !o_renaming.empty() { println!("MERGE: {}", o_renaming); }
-
         let mut fresh_o_env = Assoc::new();
         for (o_name, o_val) in o_different_env.iter_pairs() {
             fresh_o_env = fresh_o_env.set(
@@ -235,7 +233,6 @@ pub fn walk<Mode: WalkMode>(
                 } else {
                     walk_ctxt.env.clone()
                 };
-                // print!("↓↓↓↓: {:#?}\n    : {:#?}\n", beta, new_env.map(|_| "…"));
 
                 let new__walk_ctxt = walk_ctxt.with_environment(new_env);
                 let new__walk_ctxt = // If the RHS is also binding, assume it's the same

src/beta.rs

@@ -365,7 +365,7 @@ pub fn bound_from_beta(b: &Beta, parts: &EnvMBE<::ast::Ast>, quote_depth: i16) -
         }
         ShadowAll(ref sub_beta, ref drivers) => {
             let mut res = vec![];
-            for ref sub_parts in parts.march_all(drivers) {
+            for sub_parts in &parts.march_all(drivers) {
                 res.append(&mut bound_from_beta(&*sub_beta, sub_parts, quote_depth));
             }
             res
@@ -398,7 +398,7 @@ pub fn bound_from_export_beta(
         }
         ExportBeta::ShadowAll(ref sub_beta, ref drivers) => {
             let mut res = vec![];
-            for ref sub_parts in parts.march_all(drivers) {
+            for sub_parts in &parts.march_all(drivers) {
                 res.append(&mut bound_from_export_beta(&*sub_beta, sub_parts, quote_depth));
             }
             res

src/core_qq_forms.rs

@@ -229,7 +229,6 @@ pub fn unquote_form(nt: Name, pos_quot: bool, depth: u8) -> Rc<Form> {
                                 unimplemented!("We may need a stack of what NTs are quoted")
                             }
                             ctxt_elt = more_quoted_ty(&ctxt_elt, nt);
-                            println!("expected: {} ctxt: {}", expected_type, ctxt_elt);
 
                             let negative_parts = unquote_parts.switch_mode::<::ty::UnpackTy>();
                             let _res = negative_parts.with_context(ctxt_elt).get_res(n("body"))?;

src/runtime/reify.rs

@@ -170,7 +170,7 @@ impl Reifiable for () {
 
     fn reify(&self) -> Value { Value::Int(BigInt::from(0)) }
 
-    fn reflect(_: &Value) -> Self { () }
+    fn reflect(_: &Value) -> Self {}
 }
 
 impl<T0: Reifiable, T1: Reifiable> Reifiable for (T0, T1) {

src/ty_compare.rs

@@ -421,9 +421,6 @@ impl ::walk_mode::NegativeWalkMode for Subtype {
                 .destructure(u_f.clone(), &Trivial)
                 .map(|p| ast_to_name(p.get_leaf_or_panic(&n("id"))));
 
-            // print!("%%: {}\n%%: {}\n", lhs, rhs);
-            // print!("in: {:#?}\n", env.map(|_| "…"));
-
             match (lhs_name, rhs_name) {
                 // They are the same underdetermined type; nothing to do:
                 (Ok(l), Ok(r)) if l == r => {
@@ -444,13 +441,12 @@ impl ::walk_mode::NegativeWalkMode for Subtype {
         })?;
 
         // Now, resolve `:::[]:::` subtyping
-        match (&res_lhs.it, &mut res_rhs.it) {
-            (&Ty(Node(_, ref lhs_body, _)), &mut Ty(Node(_, ref mut rhs_body, _))) => {
-                // the LHS should be the subtype (i.e. already specific),
-                // and the RHS should be made to match
-                let _ = rhs_body.heal_splices__with(lhs_body, &match_dotdotdot(env));
-            }
-            _ => {}
+        if let (&Ty(Node(_, ref lhs_body, _)), &mut Ty(Node(_, ref mut rhs_body, _))) =
+            (&res_lhs.it, &mut res_rhs.it)
+        {
+            // the LHS should be the subtype (i.e. already specific),
+            // and the RHS should be made to match
+            let _ = rhs_body.heal_splices__with(lhs_body, &match_dotdotdot(env));
         }
         Some((res_lhs, res_rhs))
     }

src/unparse.rs

@@ -102,11 +102,8 @@ pub fn unparse_mbe(pat: &FormPat, actl: &Ast, context: &EnvMBE<Ast>, s: &SynEnv)
             // HACK: certain forms don't live in the syntax environment,
             //  but "belong" under an `Alt`, so just assume forms know their grammar:
             if any_scopes {
-                match actl {
-                    &Node(ref form_actual, ref body, _) => {
-                        return unparse_mbe(&*form_actual.grammar, actl, body, s);
-                    }
-                    _ => {}
+                if let &Node(ref form_actual, ref body, _) = actl {
+                    return unparse_mbe(&*form_actual.grammar, actl, body, s);
                 }
             }