Re: [Scheme-reports] Strong win later reversed: Real numbers have imaginary part #e0
Vassil Nikolov 20 Dec 2012 04:13 UTC
On Wed, 19 Dec 2012 20:06:28 -0500, Mark H Weaver <mhw@netris.org> said:
> ...
> No, several implementations (e.g. SCM, Gauche, Guile before 2.0, and
> probably others) do not even support mixed exactness complex numbers of
> this special kind, so (imag-part 2.0) => 0.0.
Well, I believe that another point of view is preferable, namely,
that (imag-part z) => 0 means that z is (certainly) a real number
and that (imag-part z) => 0.0 means that z is a complex number very
near and possibly, but not necessarily, on the real axis [*].
(Therefore, (imag-part 2.0) => 0.) But that's just my 2/100+0i.
_________
[*] the distinction between +0.0 and -0.0 here is left as an
exercise...
---Vassil.
--
Vassil Nikolov | Васил Николов | <vnikolov@pobox.com>
"Be careful how you fix what you don't understand." (Brooks 2010, 185)
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