Re: [q-lang-users] Query about Type Tests (Complex and Rational).

[John C. <co...@cc...>]

Albert Graef scripsit:

> I don't think that this is a good idea. The other type checking 
> predicates isxyz for a type Xyz all follow the scheme that the predicate 
> is equivalent to the type guard, so iscomplex should follow that 
> principle, too (that wasn't the case previously, but previously there 
> was no Complex type and iscomplex was a semantic predicate).

I'm not sure I see the utility of this.  Granted that non-numeric
types work this way, why should the numeric ones?  I'd favor a scheme
in which you use the guards for syntactic types and the isX predicates
for semantic types.  What can you do with iscomplex that you can't do
with a type guard?

Or if you think this is essential, how about going to a scheme in which
isX means "is it the representation type" and "is_X_number" means "does
it actually fit the model for that kind of number"?  So iscomplex would
be true only of objects of type Complex, but is_complex_number would be
true of any number (except hypothetical quaternions and octonions to be
added later).

In particular, is_integral_number would be true of Floats with integer
values.  A less verbose naming scheme would be good, though.

-- 
John Cowan    http://ccil.org/~cowan    co...@cc...
[T]here is a Darwinian explanation for the refusal to accept Darwin.
Given the very pessimistic conclusions about moral purpose to which his
theory drives us, and given the importance of a sense of moral purpose
in helping us cope with life, a refusal to believe Darwin's theory may
have important survival value. --Ian Johnston