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Re: truth of %nil
From: |
Neil Jerram |
Subject: |
Re: truth of %nil |
Date: |
Sun, 30 Aug 2009 12:13:59 +0100 |
User-agent: |
Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) |
Mark H Weaver <address@hidden> writes:
> This numbering has the nice properties that 0 is #f.
Just to be clear: will this mean that (SCM_BOOL_F == 0) ? As things
stand I don't think it will, because SCM_MAKIFLAG shifts and adds
0x04.
Just checking this because Ludovic said recently that (SCM_BOOL_F ==
0) would have nice properties for BDW-GC.
> Also, you may have noticed that I've been using the term "lisp"
> instead of "elisp". This is because guile may support other lisps in
> the future, and they will also need the same %nil handling. (For that
> matter, we could even use %nil to implement an "old scheme" language
> which treats '() as false.) With this in mind, should SCM_ELISP_NIL
> be renamed to SCM_LISP_NIL?
Yes, that sounds like a good argument to me - i.e. I can't see any
reason why the special-case-ness of Elisp shouldn't apply equally to
other Lisps - so please do rename "ELISP" things to "LISP", where this
argument supports that.
Thanks,
Neil