On Thu, Jan 31, 2013 at 10:05 PM, Michael Snoyman <michael@snoyman.com> wrote:

Many users won't be able to upgrade to the new network library immediately. However, adding an extra dependency on (an essentially empty) network-uri is perfectly feasible. My approach makes it possible for library authors to make their code compatible with both network 1.4 and 1.5 with just a single line change.

If you want to see examples that were more painful from the author perspective, consider the previous merging of network and network-bytestring, or the blaze-markup/blaze-html split. Both of them required adding cabal flags and conditionals to every user package that wanted to work with both versions, which definitely caused some headaches.

Someone ought to write a "How to split a package" and a "How to merge two packages" guide that carefully lists out the steps and the pros and cons of the approach.

-- Johan