Re: Proposal: splitting the network package

31 Jan 2013


      On Thu, Jan 31, 2013 at 3:28 PM, Herbert Valerio Riedel  wrote:
...
Michael Snoyman  writes:
[...]
...
* Release a new version of network (1.5) that does not include the
Network.URI module.
* Create a network-uri package that uses conditionals in the cabal file.
    * If it's compiled against network version 1.4 or earlier, it doesn't
provide any modules.
    * If it's compiled against network 1.5 or later, it provides the
Network.URI module.
This way, there's only ever one package which is providing Network.URI.
Alas, this causes some of the conditional-API issues mentioned in [1],
specifically the following situation:
Say, I have a package which specifies only its dependancy on
'network-uri' (but not 'network') for its 'Network.URI' module, then the
package compilation breaks depending on the actual version of the
'network' package linked against.
[1]: http://www.haskell.org/pipermail/libraries/2012-November/018750.html
That's true, but I don't think we have *any* means at our disposal of
creating a migration plan that has zero impact on users. The reason I
suggested my approach is that the only change users would need to make is
to add network-uri to their dependency list. You're correct that it's
possible that a user could depend exclusively on network-uri and thereby
cause trouble for users of the older network package, but I would argue
that's an acceptable tradeoff in this case.

Michael