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, 5 insertions, 0 deletions

diff --git a/lib.c b/lib.c
index 95016a33..6e14e618 100644
--- a/lib.c
+++ b/lib.c
@@ -718,6 +718,8 @@ val make_like(val list, val thatobj)
         if (from_list_meth)
           return funcall1(from_list_meth, list);
       }
+      if (thatobj->co.cls == carray_s)
+        return carray_list(list, carray_type(thatobj), nil);
       break;
     case NIL:
     case CONS:
@@ -9633,6 +9635,8 @@ val sel(val seq_in, val where_in)
 
       return newhash;
     }
+    if (seq->co.cls == carray_s)
+      goto carray;
     /* fallthrough */
   case CONS:
   case LCONS:
@@ -9650,6 +9654,7 @@ val sel(val seq_in, val where_in)
       }
     }
     break;
+  carray:
   default:
     {
       val len = length(seq);