4 files changed, 14 insertions, 2 deletions
diff --git a/lib.c b/lib.c
index 1d41ea6b..51a862b5 100644
--- a/lib.c
+++ b/lib.c
@@ -96,7 +96,7 @@ val repeat_s, rep_s, flatten_s, forget_s;
 val local_s, merge_s, bind_s, rebind_s, cat_s;
 val try_s, catch_s, finally_s, throw_s, defex_s, deffilter_s;
 val eof_s, eol_s, assert_s, name_s;
-val error_s, type_error_s, internal_error_s;
+val error_s, type_error_s, internal_error_s, panic_s;
 val numeric_error_s, range_error_s;
 val query_error_s, file_error_s, process_error_s, syntax_error_s;
 val timeout_error_s, system_error_s;
@@ -8613,6 +8613,7 @@ static void obj_init(void)
   error_s = intern(lit("error"), user_package);
   type_error_s = intern(lit("type-error"), user_package);
   internal_error_s = intern(lit("internal-error"), user_package);
+  panic_s = intern(lit("panic"), user_package);
   numeric_error_s = intern(lit("numeric-error"), user_package);
   range_error_s = intern(lit("range-error"), user_package);
   query_error_s = intern(lit("query-error"), user_package);
diff --git a/lib.h b/lib.h
index e84e5eac..3dc75d61 100644
--- a/lib.h
+++ b/lib.h
@@ -426,7 +426,7 @@ extern val repeat_s, rep_s, flatten_s, forget_s;
 extern val local_s, merge_s, bind_s, rebind_s, cat_s;
 extern val try_s, catch_s, finally_s, throw_s, defex_s, deffilter_s;
 extern val eof_s, eol_s, assert_s, name_s;
-extern val error_s, type_error_s, internal_error_s;
+extern val error_s, type_error_s, internal_error_s, panic_s;
 extern val numeric_error_s, range_error_s;
 extern val query_error_s, file_error_s, process_error_s, syntax_error_s;
 extern val system_error_s, timeout_error_s;
diff --git a/unwind.c b/unwind.c
index 7495be1e..9e0de39e 100644
--- a/unwind.c
+++ b/unwind.c
@@ -903,6 +903,7 @@ void uw_init(void)
   exception_subtypes = cons(cons(t, nil), exception_subtypes);
   uw_register_subtype(type_error_s, error_s);
   uw_register_subtype(internal_error_s, error_s);
+  uw_register_subtype(panic_s, error_s);
   uw_register_subtype(numeric_error_s, error_s);
   uw_register_subtype(range_error_s, error_s);
   uw_register_subtype(query_error_s, error_s);
diff --git a/unwind.h b/unwind.h
index fb353b15..615433e3 100644
--- a/unwind.h
+++ b/unwind.h
@@ -235,6 +235,16 @@ noreturn val type_mismatch(val, ...);
               nao);                     \
   } while (0)
 
+#define panic(STR)                      \
+  do {                                  \
+    extern obj_t *num(cnum);            \
+    uw_throwf(panic_s,                  \
+              lit("~a:~a ~a"),          \
+              lit(__FILE__),            \
+              num(__LINE__), lit(STR),  \
+              nao);                     \
+  } while (0)
+
 #define type_assert(EXPR, ARGS)         \
   if (!(EXPR)) type_mismatch ARGS