Re: Save `nil' from the mutant void, preserve the truth of falsehood, prevent the falsehood of truth

[Andy Wingo]

Hello,

On Sun 12 Sep 2010 01:33, MON KEY <address@hidden> writes:

> So, how do the Schemes handle this? Is it possible to define/set away
> #f?

In Scheme, #f and '() are not identifiers (symbols), so it is impossible
to set!  them.

> This said, Guile 1.9.10 doesn't seem to mind me let-binding `nil':
>
> scheme@(guile-user)> (let ((nil 'bubba)) nil)
> ;=> bubba

Nil does not exist in Scheme, so it is not bound. However Guile does
provide a separate nil value, which may be read as "#nil" -- again, not
an identifier.

(There is also a %nil symbol bound to #nil in the default environment
with deprecated symbols enabled, but that is a relic.)

There are still some nil-is-a-symbol-in-elisp issues to work out in
Guile. In fact there are still a number of symbols-are-fat-in-elisp,
symbols-are-just-immutable-strings-in-scheme issues to work out...

I don't think my comments have much bearing on your original comment,
though :)

Andy
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