Clearer error message for 'pattern / nil'

1 files changed, 3 insertions, 1 deletions

diff --git a/lptree.c b/lptree.c
index 30cef67..2318153 100644
--- a/lptree.c
+++ b/lptree.c
@@ -813,7 +813,9 @@ static int lp_divcapture (lua_State *L) {
       tree->key = n;
       return 1;
     }
-    default: return luaL_argerror(L, 2, "invalid replacement value");
+    default:
+      return luaL_error(L, "unexpected %s as 2nd operand to LPeg '/'",
+                           luaL_typename(L, 2));
   }
 }