New function: iterable.

* eval.c (eval_init): Register iterable intrinsic.

* lib.c (seq_iterable): New static function.
(nullify): Use seq_iterable to simplify function.
(iterable): New function.

* lib.h (iterable): Declared.

* txr.1: Documented.

1 files changed, 24 insertions, 0 deletions

diff --git a/txr.1 b/txr.1
index 05c96ae7..e0bbd032 100644
--- a/txr.1
+++ b/txr.1
@@ -29342,6 +29342,30 @@ methods are considered sequences.
 No other objects are sequences. However, future revisions of
 the language may specify additional objects that are sequences.
 
+.coNP Function @ iterable
+.synb
+.mets (iterable << object )
+.syne
+.desc
+The
+.code iterable
+function returns
+.code t
+if
+.meta object
+is iterable, otherwise
+.conp nil .
+
+If
+.meta object
+is a sequence according to the
+.code seqp
+function, then it is iterable.
+
+Additional objects that are not sequences are also iterable:
+numeric or character ranges, and numbers. Future revisions
+of the language may specify additional iterable objects.
+
 .coNP Function @ make-like
 .synb
 .mets (make-like < list << object )