Print ([...] . @var) and ([...] . @(expr)) notation.

This change fixes objects like (@a @b . @c) being printed
as (@a @b sys:var c). This is piggybacked into the logic
which renders dotted unquotes. In other words, we are already
printing (x . ,y) in that from rather than (x sys:unquote y);
we just recognize sys:var, and sys:expr in the same code.

* lib.c (obj_print_impl): Recognize dotted metavariables and
metaexpressions similarly to dotted unquotes.

1 files changed, 11 insertions, 2 deletions

diff --git a/lib.c b/lib.c
index 7c7422f2..95c1bd6b 100644
--- a/lib.c
+++ b/lib.c
@@ -13970,10 +13970,19 @@ val obj_print_impl(val obj, val out, val pretty, struct strm_ctx *ctx)
             val a = car(iter);
             val unq = nil;
 
-            if (a == sys_unquote_s)
+            if (a == sys_unquote_s) {
               unq = lit(". ,");
-            else if (a == sys_splice_s)
+            } else if (a == sys_splice_s) {
               unq = lit(". ,*");
+            } else if (a == var_s && consp(cdr(iter))) {
+              val ad = cadr(iter);
+              if (symbolp(ad) || integerp(ad))
+                unq = lit(". @");
+            } else if (a == expr_s && consp(cdr(iter))) {
+              val ad = cadr(iter);
+              if (consp(ad))
+                unq = lit(". @");
+            }
 
             if (unq) {
               val d = cdr(iter);