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bounded, infinite ranges?
- To: dyer@eagle.sharebase.com
- Subject: bounded, infinite ranges?
- From: Stavros Macrakis <macrakis@osf.org>
- Date: Tue, 20 Oct 1992 14:57:56 -0400
- Cc: info-dylan@cambridge.apple.com
- In-reply-to: Scot Dyer's message of Tue, 20 Oct 92 08:44:47 PDT <9210201544.AA01330@eagle.sharebase.com>
- Sender: macrakis@osf.org
...My reason: a range is over floats, yes? Therefore no
enumerative approach would terminate (any range has an infinite
number of elements), even if one was provided.
Huh? Floats are not reals -- after all, they're represented finitely.
As for the meaning of IEEE infinity, it is not really infinity either:
it stands for all numbers too large to represent in a given floating
type.
These values that sit outside the system, "top" and "bottom" values
are usually very important to a program. IMHO, it was unfortunate
that they were left out of the Dylan language spec.
I agree. Dylan appears to use #f as a substitute for a void value in
some cases, e.g. while, until, bind with no forms. This, and the fact
that ANY non-#f value is true, seem to be residual Lispisms.
Note that adding void to the possible returns of a function increases
function-return overhead, since of course you have to find some place
for the necessary bits.... (If you do it by some control convention,
there is still some overhead somewhere.)
-s