apply and iapply bugfix: split sequences into args.

These functions don't conform with the documentation.  For
instance [apply list "abc"] yields "abc".  It is supposed to
yield (#\a #\b #\c), since the characters of "abc" must become
individual arguments to list.  Part of the fix is in the
apply_frob_args logic; however, we have to clone that function
because it is used for implementing other things which
will break: we cannot, for for example, have (list* 1 "ab")
producing (1 #\a #\b).

* eval.c (apply_intrisic_frob_args): New static function.
Differs from apply_frob_args in that it calls tolist
on the final element.
(apply_intrinsic): Use apply_intrinsic_frob_args
instead of apply_frob_args.
(iapply): Invoke tolist on the value assigned to last_arg.

* txr.1: Add a clarifying note for iapply that the terminating
atom is not split into arguments if it is a sequence.

2 files changed, 21 insertions, 3 deletions

diff --git a/eval.c b/eval.c
index fc00a630..1584bd94 100644
--- a/eval.c
+++ b/eval.c
@@ -1106,9 +1106,24 @@ static val apply_frob_args(val args)
   }
 }
 
+static val apply_intrinsic_frob_args(val args)
+{
+  if (!cdr(args)) {
+    return tolist(car(args));
+  } else {
+    list_collect_decl (out, ptail);
+
+    for (; cdr(args); args = cdr(args))
+      ptail = list_collect(ptail, car(args));
+
+    list_collect_nconc(ptail, tolist(car(args)));
+    return out;
+  }
+}
+
 val apply_intrinsic(val fun, val args)
 {
-  return apply(fun, apply_frob_args(z(args)));
+  return apply(fun, apply_intrinsic_frob_args(z(args)));
 }
 
 static val applyv(val fun, struct args *args)
@@ -1129,7 +1144,7 @@ static val iapply(val fun, struct args *args)
   saved_ptail = ptail;
 
   if (args_more(args, index)) {
-    last_arg = args_get(args, &index);
+    last_arg = tolist(args_get(args, &index));
     ptail = list_collect_nconc(ptail, last_arg);
   }
 
diff --git a/txr.1 b/txr.1
index 09af87bf..4125f9a8 100644
--- a/txr.1
+++ b/txr.1
@@ -27062,7 +27062,10 @@ Secondly, if
 .meta trailing-args
 is a list, but an improper list, then the terminating atom of
 .meta trailing-args
-becomes an ordinary argument. Thus, in all possible cases,
+becomes an individual argument.
+This terminating atom is not split into multiple arguments,
+even if it is a sequence.
+Thus, in all possible cases,
 .code iapply
 treats an extra
 .cod2 non- nil