Re: overloaded function handles

[Robert T. Short]

John W. Eaton wrote:
> On 27-Jul-2009, John Swensen wrote:
>
> | I think patent number 6,857,118 is the more applicable one: "Function  
> | values in computer programming languages having dynamic types and  
> | overloading."
>
> Yes, sorry.  I pasted the wrong number in.
>
> |  That being said, I find it ridiculous that the ability  
> | to overload a function by string name is actually patentable.  There  
> | has got to be gobs of languages that did the same thing before this  
> | patent was issued, right?
>
> Yes,  I agree that the claims for using '@' and 'feval' seem to go too
> far, and I don't see how they could hold up, but they could.
>
> However, if I understand it correctly, that's not the major point of
> this patent.  Instead, the point is that you can create a function
> handle in one context, and then use that handle in another context to
> call a function, and the dispatch will be determined by the arguments
> given and information about which functions are available at the point
> where the funtion handle was created, not where it is used.  Do you
> know of prior art for that?  Is there a way to implement this feature
> in a way that does not use the method described in the patent?  The
> language of claim 1 seems fairly broad.
>
> jwe
>
>
>   
Just glancing through the patent, I don't see how it is possible to 
avoid infringing.  I also don't see how a patent like that ever issued, 
but that is really beside the point.  Since the patent has issued it has 
already been evaluated for obviousness and prior art.  Even if you know 
of prior art, challenging an issued patent is not likely to be a 
pleasant or cheap endeavor.

I am not a member of any patent bar so this certainly can't be taken as 
advice.  I have, however,  spent an absurd amount of time in the patent 
infringement world.  I will take a look.  It will take some weeks 
though.  I am seriously over committed at the moment.  For the time 
being, I would say not to worry about it, but we do need to recognize 
that all the Mathworks has to do is file a lawsuit and we will have to 
react - probably just by immediately pulling contested features out of 
the language (or maybe pulling octave from all U.S. distribution sites?) 
while we examine the problem.  Since there is no profit involved, there 
won't be any royalty issues, or at least I don't think so.

Bob
--
Robert T. Short, Ph.D.
PhaseLocked Systems