Added additional byte builtins

repl/evaldisplay.go

@@ -60,6 +60,28 @@ func (r *REPL) displayResult(ctx context.Context, w io.Writer, res any, concise
 		if _, err = fmt.Fprintln(w, "(nil)"); err != nil {
 			return err
 		}
+	case []byte:
+		if _, err = fmt.Fprint(w, "bytes["); err != nil {
+			return err
+		}
+		for i, x := range v {
+			if i > 0 {
+				if _, err = fmt.Fprint(w, " "); err != nil {
+					return err
+				}
+			}
+			if _, err = fmt.Fprintf(w, "%02x", x); err != nil {
+				return err
+			}
+		}
+		if _, err = fmt.Fprint(w, "]"); err != nil {
+			return err
+		}
+		if !concise {
+			if _, err = fmt.Fprintln(w); err != nil {
+				return err
+			}
+		}
 	case ucl.Listable:
 		if concise {
 			fmt.Fprintf(w, "[")