Have you considered moving these packages that are unrelated to web development into a separate namespace? I know that I never considered looking under the happstack namespace simply because I never do webapps.
On Thu, Dec 16, 2010 at 5:09 PM, Jeremy Shaw <jer...@n-heptane.com> wrote: > Hello, > > You should use happstack-data for this (you do not need the other happstack > components to use happstack-data)*. It was created to solve this exact > problem. > > happstack-data builds on type of the 'binary' library and adds versioned > data types and automatic version migration. > > You can get an idea as to how it works by reading this old blog post, > > http://nhlab.blogspot.com/2008/12/data-migration-with-happs-data.html > > The modules names have changed from HAppS.* to Happstack.*, but otherwise > it is still pretty accurate. The upcoming happstack 7 release cycle will be > focusing on this area of happstack. Especially improved documentation. But, > it is quite usable right now. > > If you have questions about happstack-data, feel free to ask on the > happstack mailing list or irc channel. (http://happstack.com/community) > > I am happy to answer any questions or concerns you may have. > > - jeremy > > * the version on hackage depends on happstack-util, but the darcs version > does not. > > On Dec 16, 2010, at 12:26 PM, Dmitry V'yal wrote: > > Greetings, > > while developing my neural net simulator I stumbled upon a problem. > > I have a data type NeuralNet and use Show and Read instances for saving and > loading configurations. As time passed, I changed the data type, so the > program can no longer load files saved in previous versions. > > I want fix it. My current idea looks as follows. I'm going to create a > bunch of types NN1, NN2, NN3..NNn for different versions and write > converters c12 :: N1 -> N2, c23 :: N2 -> N3 and so on. > > But how to organize the whole process of parsing String into NNn so it's > easy to change formats? > Something based on using a list of parsers > [read, c43 . read, c43 . c23 . read, c43, c23 . c12 . read, c43 . c32 . c21 > . read] > > looks rather verbose and grows quadratically with N. > > I'm sure there must be a more elegant way. Any ideas? > > Dmitry > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > > > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > >
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