diff options
Diffstat (limited to 'share')
| -rw-r--r-- | share/txr/stdlib/hash.tl | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/share/txr/stdlib/hash.tl b/share/txr/stdlib/hash.tl new file mode 100644 index 00000000..17d0afa2 --- /dev/null +++ b/share/txr/stdlib/hash.tl @@ -0,0 +1,41 @@ +;; Copyright 2015 +;; Kaz Kylheku <kaz@kylheku.com> +;; Vancouver, Canada +;; All rights reserved. +;; +;; Redistribution of this software in source and binary forms, with or without +;; modification, is permitted provided that the following two conditions are met. +;; +;; Use of this software in any manner constitutes agreement with the disclaimer +;; which follows the two conditions. +;; +;; 1. Redistributions of source code must retain the above copyright +;; notice, this list of conditions and the following disclaimer. +;; 2. Redistributions in binary form must reproduce the above copyright +;; notice, this list of conditions and the following disclaimer in +;; the documentation and/or other materials provided with the +;; distribution. +;; +;; THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED +;; WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF +;; MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE +;; COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DAMAGES, HOWEVER CAUSED, +;; AND UNDER ANY THEORY OF LIABILITY, ARISING IN ANY WAY OUT OF THE USE OF THIS +;; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +(defmacro with-hash-iter ((name hash-form : key val) . body) + (let ((hash (gensym)) + (iter (gensym)) + (next (gensym))) + ^(let* ((,hash ,hash-form) + (,iter (hash-begin ,hash)) + ,*(if key ^((,key))) + ,*(if val ^((,val)))) + (flet ((,name () + ,(if (not (or key val)) + ^(hash-next ,iter) + ^(let ((,next (hash-next ,iter))) + ,*(if key ^((set ,key (car ,next)))) + ,*(if val ^((set ,val (cdr ,next))))) + ,next))) + ,*body)))) |