From: Mark Wooding <mdw@distorted.org.uk>
Date: Wed, 17 May 2006 18:48:05 +0000 (+0100)
Subject: base: Export unsigned-fixnum as a handy type to have.
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/lisp/commitdiff_plain/23f32e98a31fa5df4390d28817f851a9984f6fee

base: Export unsigned-fixnum as a handy type to have.
---

diff --git a/mdw-base.lisp b/mdw-base.lisp
index e87c511..c4c3e17 100644
--- a/mdw-base.lisp
+++ b/mdw-base.lisp
@@ -28,7 +28,8 @@
 
 (defpackage #:mdw.base
   (:use #:common-lisp)
-  (:export #:compile-time-defun
+  (:export #:unsigned-fixnum
+	   #:compile-time-defun
 	   #:show
 	   #:stringify #:mappend #:listify #:fix-pair #:pairify #:parse-body
 	   #:whitespace-char-p
@@ -43,6 +44,13 @@ (defpackage #:mdw.base
 
 (in-package #:mdw.base)
 
+;;;--------------------------------------------------------------------------
+;;; Useful types.
+
+(deftype unsigned-fixnum ()
+  "Unsigned fixnums; useful as array indices and suchlike."
+  `(mod ,most-positive-fixnum))
+
 ;;;--------------------------------------------------------------------------
 ;;; Some simple macros to get things going.