Re: DIGITP

[Guy.Steele at CMU-10A]

Regarding the KMP/JAR proposal:
(1) I disagree that a separate function DIGIT-WEIGHT is needed;
    DIGITP can return the weight.  I don't think confusion of
    novices is likely; what about MEMBER, for example?
    The only argument I can think of for a separate function
    DIGIT-WEIGHT is so that it can be declared a FIXNUM function
    in MacLISP; but its range is quite restricted, and the fixnum
    "interning" mechanism will guarantee that no consing is done anyway.
(2) Even if there were a DIGIT-WEIGHT function, it also ought to take
    an optional RADIX argument.  (I argue for (DIGITP #/V 'ROMAN) => 5.)
(3) The function DIGIT-NAME exists in CHPROP under the name DIGIT-CHAR.
    It too should take an optional radix argument, returning () if
    the conversion is not possible, e.g. (DIGIT-CHAR 12. 8) => ().
(4) Minor typos: the function descriptions all think that every
    function is called DIGITP.