Subject: Re: `letf' in Common Lisp?
From: Erik Naggum <>
Date: 2000/06/02
Newsgroups: comp.lang.lisp
Message-ID: <>

* Joe Marshall <>
| I suggest that you move the setter forms to within the unwind-protect:

  Doing so gives you nothing but a false sense of improved security.

| The problem with LETF (as written) is that it will not work in a
| multitasking environment, so be careful with it.

  It will work exactly as well as, and no better than, doing the same
  settings "manually", i.e., without the macro.  This is intentional.
  The problem is not with letf, but with setting such places.  This is
  actually very important to understand: letf does not make it worse,
  but it also cannot protect you from the problem.

  If this is not what you expected, please alter your expectations.