better error message for unum conversion.

* arith.c (c_unum): When the input value is negative, complain
about that, not about uint_ptr_t, which means nothing in
TXR Lisp.

1 files changed, 1 insertions, 1 deletions

diff --git a/arith.c b/arith.c
index 62fdea53..7ebe0819 100644
--- a/arith.c
+++ b/arith.c
@@ -173,7 +173,7 @@ ucnum c_unum(val num)
       return out;
     }
   range:
-    uw_throwf(error_s, lit("~s is out of uint_ptr_t range"), num, nao);
+    uw_throwf(error_s, lit("~s given, non-negative expected"), num, nao);
   default:
     type_mismatch(lit("~s is not an integer"), num, nao);
   }