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Re: #o and unsignedness
- To: RWK at MIT-MC (Robert W. Kerns)
- Subject: Re: #o and unsignedness
- From: Guy.Steele at CMU-10A
- Date: Fri, 31 Oct 80 22:22:00 GMT
- Cc: bug-lisp at MIT-MC
- In-reply-to: RWK@MIT-MC's message of 31 Oct 80 16:13-EST
- Original-date: 31 October 1980 1722-EST (Friday)
The truncation I referred to was chopping off the poor "integer"
and forcing it to fit into a fixnum (thereby causing some bits
possibly to be lost, but in any case suddenly altering the
weight of one of its bits, from 2^25 to -2^35!!!).
There is a problem with #*O..., which is that if #B means binary
then #*B is ambiguous on a machine where just plain #* means
Letting #* vary in radix from machine to machine isn't all that
much of a problem -- the machines may have different word
lengths as well, after all.
Indeed, there is a nice symmetry between *, +, and - -- that's
why I originally proposed to use *nnnn* (the stars actually
being independent -- the treailing star was the "machine-radix point",
and the leading one meant "unsigned fixnum" -- so that -nnn*
and *ddd. actually made sense. But reason prevailed, and we
got #*, which actually is rather nice to me now.)