[Python-Dev] Comparing heterogeneous types

Jeff Epler jepler at unpythonic.net
Wed Jun 2 16:12:30 EDT 2004

Can't you do it like so:
    def cmp_long_vs_float(l, f):
            lf = float(l)
        except OverflowError:
            if special_float_value(f): # NaN, Inf
                return cmp(0.0, f)
            return cmp(l, 0L)
            return cmp(lf, f)
The try/else control flow seems to be what Python does today.
If the OverflowError is triggered, then the magnitude of l is bigger
than any finite float so you might just as well compare it against 0L.
Infinite floats are handled by the "if special_float_value(f):" branch, or
just ignored if you prefer.. (but having 2L**2000 compare greater than
+INF would bring complaints)

If it turns out to be more efficient, the implementation could LBYL to
see whether l can convert to float without overflow.

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