Felipe Almeida Lessa <felipe.lessa <at> gmail.com> writes: > > data T_orig = T_orig Foo > > $(deriveSafeCopy 0 'base ''T_orig) > > data T = T Foo Bar > > $(deriveSafeCopy 0 'extension ''T) > > instance Migrate T where type MigrateFrom T = T_Orig ... > > As you can read from deriveSafeCopy's documentation [1], you need to > increase the version of your data type (e.g. change that zero to one).
Thanks - which zero? (there are two of them.) and how does it play together with Data.Acid? Can I really rename old.T => new.T_orig ? It looks as if then tries to load the wrong acid-state snapshot. Best - J.W. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe