ffi: support sel operation on carray.

Thus (select ca '(0 3 4 ...)) works and so does the
sytnax [ca '(0 3 4 ...)]. This is inefficiently implemented.
The selected elements are extracted to a list which is then
converted to a carray of the same kind agan.

* ffi.c (carray_list): New function.
(ffi_init): Register carray-list intrinsic.

* ffi.h (carray_list): Declared.

* lib.c (make_like): Add carray case, so we can turn
a list into a carray based on an example carray.
This uses carray_list, with the type pulled from the
original carray. The target isn't null terminated.
(sel): Handle carray via vector case.

* txr.1: Document changes in select and make-like.

1 files changed, 1 insertions, 0 deletions

diff --git a/ffi.h b/ffi.h
index 88557b7b..2e88f167 100644
--- a/ffi.h
+++ b/ffi.h
@@ -95,6 +95,7 @@ val carray_type(val carray);
 val length_carray(val carray);
 mem_t *carray_ptr(val carray, val type, val self);
 val carray_vec(val vec, val type, val null_term_p);
+val carray_list(val list, val type, val null_term_p);
 val carray_blank(val nelem, val type);
 val carray_buf(val buf, val type);
 val carray_buf_sync(val carray);