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

[lisp] / mdw-base.lisp

diff --git a/mdw-base.lisp b/mdw-base.lisp
index 37a30684330953cea4daaa00702f2fb116be4e32..c4c3e1748224af8bb00c0c73d3aa98363880ca71 100644 (file)
--- a/mdw-base.lisp
+++ b/mdw-base.lisp
@@ -28,12 +28,13 @@
 
 (defpackage #:mdw.base
   (:use #:common-lisp)
 
 (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
           #:slot-uninitialized
           #:show
           #:stringify #:mappend #:listify #:fix-pair #:pairify #:parse-body
           #:whitespace-char-p
           #:slot-uninitialized

-          #:nlet #:while #:case2 #:ecase2
+          #:nlet #:while #:until #:case2 #:ecase2

           #:with-gensyms #:let*/gensyms #:with-places
           #:locp #:locf #:ref #:with-locatives
           #:update-place #:update-place-after
           #:with-gensyms #:let*/gensyms #:with-places
           #:locp #:locf #:ref #:with-locatives
           #:update-place #:update-place-after


@@ -43,6 +44,13 @@ (defpackage #:mdw.base
 
 (in-package #: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.
 
 ;;;--------------------------------------------------------------------------
 ;;; Some simple macros to get things going.
 


@@ -189,9 +197,11 @@ (defmacro nlet (name binds &body body)
 
 (defmacro while (cond &body body)
   "If COND is false, evaluate to nil; otherwise evaluate BODY and try again."
 
 (defmacro while (cond &body body)
   "If COND is false, evaluate to nil; otherwise evaluate BODY and try again."

-  `(loop
-     (unless ,cond (return))
-     ,@body))
+  `(loop (unless ,cond (return)) (progn ,@body)))
+
+(defmacro until (cond &body body)
+  "If COND is true, evaluate to nil; otherwise evaluate BODY and try again."
+  `(loop (when ,cond (return)) (progn ,@body)))

 
 (compile-time-defun do-case2-like (kind vform clauses)
   "Helper function for `case2' and `ecase2'."
 
 (compile-time-defun do-case2-like (kind vform clauses)
   "Helper function for `case2' and `ecase2'."