Patents use their own specific, strange language. The claims, as modified by other precedents, only apply in certain specific situations which may be different than what a casual reading would imply. And, for any of dozens of reasons the holder may not be interested in ever trying to enforce the patent.
So simply by raising the possibility, causing attention to be drawn, and uninformed discussions to be spawned, people's time is being wasted. If they become uneasy, or start spending engineering effort to 'work around' something that they hardly understand and that may never be enforced, more time is wasted.
And by getting more eyes on the fuzzy patent, you may have put more people/projects at risk of treble damages for 'willful infringement', in the rare case where the patent is actually enforced later, or undermined their ability to make a case for obviousness (because many teams came up with the same approach without seeing the patent).
The better policy is to ignore such "appears to be patented" reports, unless and until there's a credible threat from the holder(s) to enforce in specific ways, as checked by experts. Let these patents (and panicked overbroad interpretations) wither away in unenforced obscurity.
Which brings me to my point : imho the chances that humans are capable of real original thought is nil. Don't get me wrong, humans are very capable of creatively combining ideas from very different disciplines and non-human sources to arrive at surprising insights and works. But I'm pretty sure humans are not in fact capable of creating something out of nothing, even when it comes to intellectual works.
Patenting a data structure sounds ridiculous, but it's a little less ridiculous once you consider how complex the underlying algorithms actually are.
JPEG was patented. I can understand why. It was novel, it was not obvious, and it was useful. That trio makes a pretty good case for patentability, ignoring whether algorithms can/should be patented in general.
From what I've read, Judy arrays are novel, not obvious (moreso than JPEG, in my subjective opinion), and useful. So it doesn't seem far fetched to patent Judy arrays, ignoring whether algorithms can/should be patented in general.
Which is why I said "a little less ridiculous". This has nothing to do with complicated math, even though both data structures/algorithms involve complicated math.
JPEG met the novelty, non-obviousness, and usefulness tests, as did LZW. That they're considered nearly trivial these days is because they were such influential algorithms that they've become part of the programming canon.
That said, please don't represent my stance as a matter of a cutoff. Many things in this world, including the question of patentability, are fuzzy distinctions that require some subjective "good judgement." Common law legal systems are bad at handling this, which is partly why judicial philosophy is so complex.
If I oppose patenting an algorithm/data structure, it's because I don't think patent protection is necessary in order for people to push the state of the art forward.
Patent law is a black-on-white subject, either you support it or not. It's impossible to grant some patents under subjective premises and be fair at the same time.
Is that not the job of patent examiners?
The idea behind patents is protecting the innovator. How does patent law protect anyone when it's trivial to argue a patent shouldn't have been granted in the first place (because it's not novel, or it's just math, blah blah)? You could say that about all patents ever filled.
It defeats the whole purpose behind patents. Whoever has the biggest patent pool and deepest pocket wins, not the little guy on the sweatshop. The only people to benefit from patents are lawyers.
I can tell you mathematically how a windmill grinds corn but that does not make my description into a windmill. On the other hand, laying down the mathematical description of a Judy Array IS the array itself!
How is that true? Isn't a description a model [1], never the thing itself?
http://en.wikipedia.org/w/index.php?title=Judy_array&dif...
"Removed speculation that this subject is related to the referenced patent. Wikipedia is not a crystal ball or a place to discuss how the law MAY be applied."
For instance, just off the top of my head, consider this: "OK, you can distribute the source all you want, but as soon as you compile it, you've created a patented product, the binary of which you can't distribute."
After all, the patent itself is supposed to give all the description one needs of how to implement the patented invention, it's when you fix the patent into something real that you violate the patent.
Edit: What drove me to mentioning the separateness of patents and copyright was some of the discussion around GPLv3, e.g. http://fsfe.org/campaigns/gplv3/patents-and-gplv3.en.html#Ex...
If a separate implementation is NOT a derived GPL work, then patent licensing may be a factor.(IANAL etc.)
tl;dr: patent was done for defensive reasons.
http://preshing.com/20130107/this-hash-table-is-faster-than-...
(yes, this hash table is vulnerable to timing attacks; point is, for many workloads Judy brings in considerable complexity but is actually inferior to other solutions).
See http://nothings.org/computer/judy/ for a more thorough analysis of Judy arrays (at 20 kLoC) versus straightforward hash tables (at 0.2 kLoC).
You can't patent an algorithm, at least not in the U.S. The expression of an algorithm can be patented. Patent lawyers often tell people to replace an algorithm with a system, which is an expression of the algorithm.
