Loose ends

[Robert A. Cassels <Cassels%SCRC-TENEX%MIT-ML@SU-DSN>]

    Date: Wed, 8 Jun 1983  12:58 EDT
    From: Scott E. Fahlman <Fahlman@CMU-CS-C>
    Just a couple of loose ends to tie up.  I am swapping out for a few days
    and Guy may be in a position to finish up a draft of the manual before I
    return, so I would like to just propose a couple of things that will go
    in if nobody objects by the time he gets to them.  I think that these
    proposals will be uncontroversial, but I've been wrong before on such
    issues.

    1. FLOAT-SIGNIFICAND and FLOAT-INTEGER-SIGNIFICAND are now confusing
    names, given the change in semantics approved by the last ballot.
    I propose that these be called DECODE-FLOAT and INTEGER-DECODE-FLOAT,
    unless a better name is proposed within the next 24 hours or so.  I
    propse that the determination of "better" will be done by Guy.

    2. Whatever we call the functions listed above, it is proposed that they
    return a third value which is the sign of the number, in the format
    currently supplied by a one-arg call to FLOAT-SIGN.  The rationale is
    similar to the rationale for combining the significand and the exponent:
    whenever you want any of these, you almost always want all of them.  I
    suggest that we leave it up to Guy to decide whether, given this change,
    FLOAT-SIGN is useful enough to keep.

There is probably still some use for the two-argument FLOAT-SIGN.  I do
agree that the functions in (1.) should return the sign as a third
value.

I guess I would like to amend slightly my proposal on FLOAT-DIGITS and
FLOAT-PRECISION, to combine them into a single function returning two
values, for reasons similar to those which led to combining
FLOAT-SIGNIFICAND, etc.  But I don't feel strongly about it or the names
I proposed and am willing to leave it to Guy's judgement.  (Guy -- you
wondered why I wanted this information for printing.  It's strictly for
doing the thing suggested by the IEEE standard, where denormalized
numbers are printed with leading zeros.)