Which raises some questions (again) of the semantics of constant
patterns for exotic floating point values, especially (again)
negative zero.
In a switching context, I think there is a stronger case for
distinguishing between +0.0 and -0.0. The operational semantics I'd
recommend are to desugar, say a float switch, to an int switch on the
Float.floatToIntBits mapping of the float case labels.
Float.floatToIntBits, as opposed to Float.floatToRawIntBits,
normalized all NaN representations to a single value.
This sounds right to me, but its not just about switch -- this would
have to be the case for all constant patterns, such as
if (x instanceof FloatHolder(Float.NaN)) { ... }
But I think your argument still applies here as well.
