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From: Stefan Monnier <monnier@iro.umontreal.ca>
Newsgroups: gmane.emacs.help
Subject: Re: Replacement for Common Lisp's GENSYM in Emacs Lisp
Date: Mon, 08 Mar 2010 21:33:53 -0500
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>> Nothing, but luckily it doesn't make any difference whether they are
>> or not.

> Your "dotimes" macro produces:

> (let ((list '(1)) (result ()))
>   (dotimes (i '(1 2 3)) (push list result))
>   result) => ((3) (2 3) (1 2 3))

> While a version which doesn't shadow "list" produces this:

> (let ((list '(1)) (result ()))
>   (dolist (i '(1 2 3)) (push list result))
>   result) => ((1) (1) (1))

Because you're trying it out in Elisp (which uses dynamic scoping),
whereas this technique relies on lexical-scoping.


        Stefan