[R6RS] string->number

dyb at cs.indiana.edu dyb at cs.indiana.edu
Wed Aug 30 12:35:40 EDT 2006

> The R6RS does not assume that inexact numbers are
> represented in floating point, and certainly does
> not assume they are represented in IEEE floating
> point.

True, but it shouldn't preclude a sensible implementation based on IEEE

> More importantly, implementations are not supposed
> to return an exact number for things like (/ 0 0.0)
> unless they can prove that the result they want to
> return is the correct result for all substitutions
> of exact numbers for the inexact ones.

Is this new in R6RS?  If so, I object.  The R5RS requirement was less
stringent and, by the way, specifically allowed (* 0 x) to be 0 for any
number x including, presumably, NaNs.

> Your argument above does not convince me that 0 is
> the correct result of (/ 0 0).

It's a relief to know that I haven't convinced you of something I don't
believe myself.


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