New function: iterp.

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

* lib.[ch] (iterp): New function.

* tests/012/iter.tl: New tests.

* txr.1: Document iterp. Update documentation for iter-more,
iter-item and iter-step to more precisely identify which
objects are valid arguments in terms of iterp and additional
conditions, and that other objects throw a type-error
exception. Fix wrong references to iter-more under
documentation for iter-item.  Removed obsolete text specifying
that iter-step uses car on list-like sequences, a dubious
behavior removed in the previous commit.

1 files changed, 1 insertions, 0 deletions

diff --git a/lib.h b/lib.h
index a17a6d6d..649fc291 100644
--- a/lib.h
+++ b/lib.h
@@ -775,6 +775,7 @@ val iter_more(val iter);
 val iter_item(val iter);
 val iter_step(val iter);
 val iter_reset(val iter, val obj);
+val iterp(val obj);
 val iter_catv(varg iters);
 val copy_iter(val iter);
 void seq_build_init(val self, seq_build_t *bu, val likeobj);