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I have seen a lot of incorrect Comparators and Comparable implementations in existing code, but haven’t personally come across the infinite-loop situation yet.
by layer8 2y ago
I have seen a lot of incorrect Comparators and Comparable implementations in existing code, but haven’t personally come across the infinite-loop situation yet.
To give one example, a common error is to compare two int values via subtraction, which can give incorrect results due to overflow and modulo semantics, instead of using Integer::compare (or some equivalent of its implementation).
- smarks 2y agoInteresting. I haven’t seen an infinite loop either, but I can imagine one if a comparator tries to be too “clever” for example if it bases its comparison logic on some external state. Another common source of comparator bugs is when people compare floats or doubles and they don’t account for NaN, which is unequal to everything, including itself! In Java, the usual symptom of comparator bugs is that sort throws the infamous “Comparison method violates its general contract!” exception.