PackageDescription: SYSBUG-FloatComparison


SYSBUG - Float Comparison

Last published: March 3, 2021 by 'nice'

Defines 0 Classes
Extends 7 Classes

This is a patch against following Equality transitivity problems

| a b c |
a := 16r1FFFFFFFFFFFFF0.
b := a asDouble.
c := a + 1.
(a = b) & (b = c) ifTrue: [self assert: (a = c)]
"note: this is squeak imply operator
self assert: (a = b) & (b = c) ==> (a = c)"


| a b c |
a := 16r1FFFFFFFFFFFFF0.
b := a asDouble.
c := a + 1.
(a = b) & (a < c) ifTrue: [self assert: (b < c)]
"note: this is squeak imply operator
self assert: (a = b) & (a < c) ==> (b < c)"

Current implementation (in VW/Squeak/Dolphin/STX/gst etc...) is incorrectly coercing to Double in order to perform comparisons.

I claim on the contrary that it should convert double asFraction in order to perform comparison.

These bugs have various consequences on Sets (size might depend on order which elements are added)

And it is scratching formal beauty of my favourite language.

Please include it in your image.

From nicolas cellier