Hi,
I found this on comp.lang.functional, does this affect Lisp
in any way? I am surprised if there are no prior art on
multi-methods (even at compile-time) for lispy languages.
Anyone?
""""
·····@alum.mit.edu (Neelakantan Krishnaswami) writes:
> Hello all,
>
> Like every other functional programmer in the universe, one of my
> hobbies is designing and implementing yet another functional
> programming language. :) In my case, I decided to implement an OO
> language with multimethods, and decided to use Bourdoncle and Merz's
> ML-sub type system as the base for my language.
>
> However, a few days ago I ran into a reference to a patent by Rakesh
> Agrawal, Linda G. de Michiel, and Bruce G. Lindsay: "Methods to
> Support Multimethod Function Overloading with Compile-Time Type
> Checking," US patent #5,696,974.
>
> <URI:http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF
> &d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1='5,696,974'.WKU.
> &OS=PN/5,696,974&RS=PN/5,696,974>
>
> (You will need to fix the line breaking for the URL.)
>
> I read the patent, and *think* that I'm okay, but couldn't really make
> too much sense of it because it's written in legalese. Does anyone
> have any URLs to their academic papers describing the algorithms? I'd
> like to make sure that I'm not infringing on their patent before
> proceeding much further.
>
>
> Neel
""""
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Stig E Sandoe ····@ii.uib.no http://www.ii.uib.no/~stig/
····@ii.uib.no (Stig E. Sandoe) writes:
> I found this on comp.lang.functional, does this affect Lisp
> in any way? I am surprised if there are no prior art on
> multi-methods (even at compile-time) for lispy languages.
> Anyone? [...]
No comment on the patent other than the general remark that I'm not a
fan of the present software patents mechanism as a way of protecting
intellectual property.
A google search turned up that this patent was issued 2-3 years ago.
It's not the only patent held by Rakesh Agrawal for IBM. This page
documents numerous others:
http://www.almaden.ibm.com/cs/people/ragrawal/patents.html
- - - - -
On a related topic:
There's also a more recent one by the same guy that has to do with
multi-method dispatch on parallel processors by what sounds at first
blush like a fairly obvious divide and conquer approach... I read only
the abstract, not the details. Maybe there's more subtlety to it, but
it certainly has the smell of "first person to grab what any student
would have suggested if assigned this project for homework and
therefore what no one should have grabbed" rather than "first person
to discover an obscure thing that required special incentive from a
national government to make sure the world found out about".