Re: [Haskell-cafe] help with safecopy + acid-state

Felipe Almeida Lessa 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.