darcs patch: [PROOF OF CONCEPT] build readline package with libedit

[Simon Marlow]

Christian Maeder wrote:
> Simon Marlow wrote:
>> Judah Jacobson wrote:
>>> I've actually put together a readline-compat package like you described:
>>>
>>> http://code.haskell.org/readline-compat
>> This is not the way to go, IMO.  As Manuel said, we don't want packages
>> with licenses that depend on the way the package is built.  The
>> readline-compat package above has this problem, and the only way to fix
>> it is to make its license GPL.  But presumably that's exactly what you
>> don't want to do, because the purpose of using editline is to avoid the
>> GPL.
> 
> My major aim was to avoid that users of our software need to install the
> GNUReadline.framework (or libreadline) on their macs (although we could
> probably also link libreadline and libncurses statically.)

As far as I can see, you don't need a package with a variant license in 
order to do what you want.  The package in question just has an option to 
use editline instead of readline at build-time.

If you want to make life even easier, do as was suggested before and add a 
module with a single compatible API to both editline and readline, so 
clients can use the same API regardless of which package they link against.

>> Packages which want to use either editline or readline should say so in
>> their .cabal files, we cannot abstract this choice into a package of its
>> own.
> 
> You also abstract the choice between windows and unix. Doesn't that have
> license implications, too?

I'm not aware of any license implications - what problem specifically are 
you referring to?

Cheers,
	Simon