HaloO
Darren Duncan wrote:
Up front, I will say that, all this stuff about 1 vs 1.0 won't matter at
all if the Int type is an actual subset of the Num type (but whose
implementation is system-recognized and optimized), meaning that Int and
Num are not disjoint, as "most folks" usually expect to be the case,
such that, eg, 1 === 1.0 returns true.
I agree to that except for the last statement. I think that 1 === 1.0
should be False because the involved types are different. This e.g.
also applies to 1.0 === Complex(1.0,0.0) which should be False. In
both cases we should have numeric equality, i.e. 1 == 1.0 and
1.0 == Complex(1.0,0.0) are True. And of course we have the subtyping
chain Int <: Num <: Complex.
The Gaussian integers are a subtype of Complex and a supertype of
Int but not of Num. So in the end we have the type lattice
Complex
/ \
Num Gaussian
\ /
Int
It's interesting how this Gaussian type might be fitted in after the
other three. The link from Int to Gaussian needs a supertyping
construct. Something like 'role Gaussian does Complex superdoes Int'.
So consider this as an addendum to the supertyping thread.
Regards, TSa.
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