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Re: #O, an alternate view
- To: Robert W. Kerns <RWK at MIT-MC>
- Subject: Re: #O, an alternate view
- From: Guy.Steele at CMU-10A
- Date: Fri, 31 Oct 80 20:07:00 GMT
- Cc: bug-lisp at MIT-MC
- In-reply-to: Robert W. Kerns's message of 31 Oct 80 11:47-EST
- Original-date: 31 October 1980 1507-EST (Friday)
Fine, let #o be only unsigned. But that is a different issue
from deciding at what point to truncate it (word size). There are
some applications where you want to use a bignum as a bit string
(especially on the PDP-10, which unlike NIL doesn't have a BITS),
on which to use bignum BOOLE or HAIPART, etc. (I think Pratt does
some of this kind of thing.)
Think of it this way: #o is the *portable* way to get bit patterns,
and #* is the way to get *machine-dependent* bit patterns. The
fact that you can use one to get the other (sometimes) is no more
excuse for confusing them than is using CDR when you mean PLIST,
even though that also works (sometimes).