[squeak-dev] a==b "true" but a=b "false"
Chris Muller
ma.chris.m at gmail.com
Wed Sep 3 23:11:53 UTC 2014
When could it happen?
A: With Float nan.
Float nan == Float nan "true"
Float nan = Float nan "false"
It violates what I have long considered an invariant that if a==b, then a=b.
Real world context: When two DB clients change the same object in the
exact same way, it's not a conflict. If they change it differently,
it is.
They've both made the same reference to Float nan, but just asking if
they made equivalent changes still reports false. So I have to put in
a complicated special check for NaN first..??
Okay, I actually wrote: (a==b or: [a=b]) but who would ever write
that or not "simplify it" in teh future if they saw it?
Comments? Why shouldn't Float nan = Float nan?
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