Cabal && license combinations

[Duncan Coutts]

On Mon, 2011-02-07 at 14:42 +0000, Malcolm Wallace wrote:
> > It seems then that a package should be the least restrictive  
> > combination of all the licenses in all the contained modules.
> 
> Omit the words "least restrictive" and I think you are correct.
> 
> To combine licences, just aggregate them.  There is no lattice of  
> subsumption; no "more" or "less" restrictive ordering.  It's simple:  
> you must obey all of them.  Some aggregations introduce a  
> contradiction of terms, so you cannot legally aggregate those modules  
> without breaking some term.  But if the terms of the aggregated  
> licences are compatible rather than contradictory, then all is good.

Right, so the effect of per-file/mixed licenses could be achieved by
letting packages specify a list of licenses:

license: Foo, Bar

Meaning you may copy/distribute provided you comply with all these
licenses.

Note that this does not cover dual licensing, e.g. Foo or Bar at
distributor's choice.

Duncan