On Wed, Sep 23, 2009 at 12:46:02PM -0400, John Cowan wrote: > I'm not sure I follow you.
Sorry, my fault: terminology thinko. I thought that you were arguing against *literal* floats. My C/assembler background hasn't quite let go yet, and I still think of most such uses as "immediate". > By "immediate floats" I mean ones that are > stuffed into the same space as a pointer, but are distinguishable from > it, exploiting the fact that pointers on modern hardware almost always > have 000 or 0000 in the bottom few bits. This is commonly done in Scheme > for fixnums, characters, #t, #f, and (). > > Some implementations have tried to put chopped versions of 32-bit > IEEE single-floats into 32-bit pointer space in the same way; it is > this practice I was warning against, because of the cumulative error > resulting from truncating instead of proper rounding. Sure, that would be bad. In support of that, I keep trying to figure out how a compiled scheme could manage to feel like scheme while not using type tags: at the moment I'm into a combination of boxing (with bibop meta-data) and ... it seems very difficult. I'm not much of a compiler guru, I'm afraid. Sorry for the noise. Cheers, -- Andrew _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
