newtype VMT m a =
VMT {runVMT :: StateT VMState m a}
deriving (Monad, MonadIO, MonadTrans, TransM, MonadState VMState)
works here (ghc-6.10.3)
On Wed, Sep 16, 2009 at 11:42 AM, Miguel Mitrofanov
<[email protected]> wrote:
> newtype VMT m a =
> VMT {runVMT :: StateT VMState m a}
> deriving (Monad, MonadIO, MonadTrans, TransM)
>
> Unfortunately, you can't automatically derive MonadState, since it's a
> multi-paremeter type class. You'll have to write down the derivation
> yourself.
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