[Haskell-cafe] Automatic derivation (TemplateHaskell?)

Joel Reymont joelr1 at gmail.com
Thu Apr 5 05:23:15 EDT 2007


What version of ghc are you using? Mine is 6.6.

     Could not find module `Control.Monad.State':
       it is a member of package mtl-1.0, which is hidden

I commented out that import line.

Preprocessing library derive-0.1...
Preprocessing executables for derive-0.1...
Building derive-0.1...
[1 of 9] Compiling Data.Derive.FixedPpr ( Data/Derive/FixedPpr.hs,  
dist/build/Data/Derive/FixedPpr.o )
[2 of 9] Compiling Data.Derive      ( Data/Derive.hs, dist/build/Data/ 
Derive.o )
[3 of 9] Compiling Data.Derive.SYB  ( Data/Derive/SYB.hs, dist/build/ 
Data/Derive/SYB.o )
[4 of 9] Compiling Data.Derive.TH   ( Data/Derive/TH.hs, dist/build/ 
Data/Derive/TH.o )

     No instance for (Functor Q)
       arising from use of `fmap' at Data/Derive/TH.hs:25:26-31
     Possible fix: add an instance declaration for (Functor Q)
     In the first argument of `(.)', namely `fmap f'
     In the expression: (fmap f) . deriveOne
     In the definition of `derive':
         derive (Derivation f _) = (fmap f) . deriveOne

This I don't know how to deal with.

	Thanks, Joel


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