matcher: fix semantics of empty @(all ...) match.

* lisplib.c (match_set_entries): Ensure usr:all* is interned.

* share/txr/stdlib/match.tl (compile-all-match): When the
operator is the existing all, we must listp as a guard, not
consp, because an empty list must match vacuously by virtue of
not containing any counterexample to the pattern. For
situations when a vacuous empty match is not desired, we
support the all* alternative operator, which uses consp.
(compile-match): Wire in the all* operator.

1 files changed, 6 insertions, 0 deletions

diff --git a/lisplib.c b/lisplib.c
index a77ff015..fa6022de 100644
--- a/lisplib.c
+++ b/lisplib.c
@@ -869,11 +869,17 @@ static val match_instantiate(val set_fun)
 
 static val match_set_entries(val dlt, val fun)
 {
+  val name_noload[] = {
+    lit("all*"),
+    nil
+  };
   val name[] = {
     lit("when-match"),
     nil
   };
+
   set_dlt_entries(dlt, name, fun);
+  intern_only(name_noload);
   return nil;
 }