Re: Potential copyright problem in EIEIO improvement

[Jan Moringen <jan.moringen@uni-bielefeld.de>]

On Thu, 2009-12-31 at 21:55 -0500, Richard Stallman wrote:
> Thank you for your opinion on this. Regarding the "if" part, there
> are
>     two parts: the canonical Dylan linearization, upon which the paper
>     (mentioned in my original message) is improving and the actual
>     improvement. The code above corresponds to the improvement. My
> patch
>     also has parts derived from the unchanged parts of the canonical
>     implementation.
> 
> You have lost me; I can't follow the scenario.

Sorry. Let me start over. 

I would like to contribute an improvement to EIEIO which consists of the
implementation of an algorithm (called c3 linearization) for computing
class precedence lists. My implementation in Emacs Lisp is based on an
implementation in Dylan that has been published in an academic paper
[1].

The Dylan code presented in that paper consists of two parts: the class
precedence list computation currently used in Dylan and an improved
version (the c3 linearization). Two thirds of the improved version are
identical to the old implementation. The old implementation is available
under GPL, for example in Open Dylan.

My code is derived from both parts of the Dylan code.

> What I can say is that, in general, we do not want to incorporate
> code into Emacs without a copyright assignment.

I have written all the code that would go into EIEIO and I have signed
the copyright assignment forms for both GNU Emacs and CEDET. The
copyright assignment should not be a problem. The question Eric and I
could not answer is whether incorporating my code and assigning the
copyright could lead to copyright problems because of the way that code
came into existence.

Kind regards,
Jan

[1] Kim Barrett et al.: A Monotonic Superclass Linearization for Dylan
    http://192.220.96.201/dylan/linearization-oopsla96.html