Re: rationals as a Lisp data type

[George J. Carrette <GJC at MIT-MC>]

    Date: 24 Dec 1980 09:03:46-PST
    From: CSVAX.fateman at Berkeley

    I do not object to a data type which is expensive and useful.  I
    suspect however, that rationals will be found to be less useful
    than, for example, bigfloats or what Collins calls "binary
    rationals" (power of 2 denominators), or perhaps IEEE standard
    floating point.


I would put in a strong object to so called bigfloats. Most of the
time I've seen them used by macsyma users to substitute numerical
brute force for mathematical thoughtfulness. The better understood
rational data type makes the classic numerical pitfalls obvious.

Regardless, its clearly more fruitful to have methods in the lisp
language (make that "lisp system") to add data types which are
"on par" (in "efficiency" and error checking provided) with the built-in
data types, then it is to add more basic types.
Maybe it isn't clear, but the different ways of doing it are
obviously a more interesting subject to argue on.