from Hacker News

Judy arrays are patented

by CesareBorgia on 1/11/13, 5:17 PM with 56 comments

  • by gojomo on 1/11/13, 7:36 PM

    Unless you are a patent lawyer/expert specifically in someone's employ, pointing out that in your layman's opinion that "something appears to be patented" isn't doing anyone any favors, and may in fact be harming them.

    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.

  • by kleiba on 1/11/13, 8:09 PM

    At the same time, Doug Baskins, the author of Judy, open sourced an implementation under the LGPL [1]. This license insists "that any patent license obtained for a version of the library must be consistent with the full freedom of use specified in this license." [2]

    [1] http://judy.sourceforge.net/downloads/10minutes.htm

    [2] http://www.gnu.org/licenses/lgpl-2.1.html

  • by wheaties on 1/11/13, 6:29 PM

    You can patent a data structure!? Seriously? This is straight up an abstract idea. I think non-abstract patents are beneficial and help society. This is just plain idiocy.

  • by aspensmonster on 1/11/13, 8:13 PM

    Since the article has been updated and the "Drawbacks" section removed, here's the diff showing the original contents of the "Drawbacks" section that the story linked to, along with the deletion by user Fintler:

    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."

  • by rossjudson on 1/11/13, 6:57 PM

    It's released under the LGPL, according to its COPYING file, by HP. I am pretty sure that means the patent doesn't matter; HP is granting you a license to use it.

  • by batgaijin on 1/11/13, 7:51 PM

  • by millrawr on 1/12/13, 3:06 AM

    I actually asked about this on the mailing list some time ago: http://comments.gmane.org/gmane.comp.lib.judy.devel/244

    tl;dr: patent was done for defensive reasons.

  • by zrail on 1/11/13, 6:45 PM

    This has been true for quite a long time, and IIRC is why they're not more widely used. That and they're pretty complicated to implement properly.

  • by ww520 on 1/11/13, 8:46 PM

    Are we talking about the implementation is patented? Or the algorithm itself is patented?

    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.

  • by cbsmith on 1/11/13, 8:15 PM

    In case of patent lawyers, break glass and extract HAT-trie or crit-bit tree.

  • by codeulike on 1/11/13, 6:40 PM

    using System.Collections.Patented;

  • by dakimov on 1/11/13, 7:55 PM

    That's no problem, actually, even if it is patented, because Judy Array is not a concise algorithm or a data structure, but instead a compilation of a number of well-known unpatented data structures and algorithms, so you can basically change a couple of algorithms used there, and get out of the patent.