On Sat, 05 Sep 2009 15:41:19 -0400, John Cowan <[email protected]> wrote:
> The old gensym trick provides only half of hygiene: it prevents names
> bound in the macro from leaking to the macro's caller. But it does
> nothing, and no amount of fiddling with define-macro can do anything,
> about names free in the macro (or bound at the definition point) from
> being overridden by the bindings at the time of call. Without full
> hygiene, macro writers and users are playing with knives.
Indeed, hygienic macros provide a level of reliability in the code that
can't be expressed without them; at least, not easily.
Aaron W. Hsu
--
Of all tyrannies, a tyranny sincerely exercised for the good of its
victims may be the most oppressive. -- C. S. Lewis
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