Re: comments on latest draft
William D Clinger 07 Jun 2017 03:48 UTC
This is my third set of comments on the draft at
http://vrici.lojban.org/~cowan/temp/srfi-144.html
Why must the argument to make-fllog-base be an exact integer?
It would be a lot more useful *and* easier to implement if
that argument were allowed to be any finite flonum greater
than 1.0.
The specification of flloggamma is incorrect. Its first return
value should be log(|Gamma(x)|), not log(Gamma(|x|)).
The spec for fl+* says it computes its result "as if to infinite
precision and rounded only once." That's fine as an aspirational
goal, but it's overly ambitious as a requirement. To implement
it portably, or on hardware that doesn't have machine instructions
that satisfy the requirement, satisfying the requirement probably
involves conversion to an exact representation for the operations
followed by conversion back to a flonum. That's going to be quite
slow. If speed is one of this procedure's goals, as I gather from
the discussion, the SRFI shouldn't impose absolute requirements
that force implementors to make the procedure much slower (on some
platforms) than the obvious composition.
Will Clinger