From 6b2d8d5fe2556316c6cff7f876153716ce296183 Mon Sep 17 00:00:00 2001 From: Aaron Zeng Date: Tue, 21 Apr 2015 15:08:39 -0400 Subject: [PATCH] fix the while macro for Common Lisp Earlier version was incorrect, as it only executed `body` once and then terminated, like an if statement instead. --- common-lisp.html.markdown | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/common-lisp.html.markdown b/common-lisp.html.markdown index c4ecb5e8..f9f64d68 100644 --- a/common-lisp.html.markdown +++ b/common-lisp.html.markdown @@ -573,13 +573,15 @@ nil ; for false - and the empty list "While `condition` is true, `body` is executed. `condition` is tested prior to each execution of `body`" - (let ((block-name (gensym))) + (let ((block-name (gensym)) (done (gensym))) `(tagbody + ,block-name (unless ,condition - (go ,block-name)) + (go ,done)) (progn ,@body) - ,block-name))) + (go ,block-name) + ,done))) ;; Let's look at the high-level version of this: