From e9ccb0a5bde9d17138de720dc7afbc7fe25f6e33 Mon Sep 17 00:00:00 2001
From: Jesse Brault <jbrault@mac.com>
Date: Sun, 14 Sep 2025 21:15:48 -0500
Subject: [PATCH] Add default rule match panic branch.

---
 ast-generator/src/leaf_enum_build_fn.rs | 3 ++-
 ast-generator/src/struct_build_fn.rs    | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/ast-generator/src/leaf_enum_build_fn.rs b/ast-generator/src/leaf_enum_build_fn.rs
index c40d3b9..9ff9813 100644
--- a/ast-generator/src/leaf_enum_build_fn.rs
+++ b/ast-generator/src/leaf_enum_build_fn.rs
@@ -29,7 +29,8 @@ pub fn make_leaf_enum_build_fn(leaf_enum_build_spec: &LeafEnumBuildSpec) -> Toke
         fn #build_fn_ident(#pair_ident: Pair<Rule>) -> #return_type_ident {
             let inner_pair = #pair_ident.into_inner().next().unwrap();
             match inner_pair.as_rule() {
-                #(#rule_branches),*
+                #(#rule_branches,)*
+                _ => panic!("Unexpected rule: {:?}", inner_pair.as_rule())
             }
         }
     }
diff --git a/ast-generator/src/struct_build_fn.rs b/ast-generator/src/struct_build_fn.rs
index bb1380c..10d3523 100644
--- a/ast-generator/src/struct_build_fn.rs
+++ b/ast-generator/src/struct_build_fn.rs
@@ -248,6 +248,7 @@ pub fn make_struct_build_fn(build_spec: &StructBuildSpec) -> TokenStream {
         for inner_pair in #pair_ident.into_inner() {
             match inner_pair.as_rule() {
                 #(#rule_matchers)*
+                _ => panic!("Unexpected rule: {:?}", inner_pair.as_rule())
             }
         }
     };