> module Paradise (increase) where

> import GL
> import CompanyDatatypes
> import CompanyReps
> import Data.Generics hiding (Generic)

% - - - - - - - - - - - - - - - = - - - - - - - - - - - - - - - - - - - - - - -
\subsection{Function show}
% - - - - - - - - - - - - - - - = - - - - - - - - - - - - - - - - - - - - - - -

> newtype Gincrease a           =  Gincrease { applyGincrease :: Float -> a -> a }

> instance Generic Gincrease where
>   unit                        =  Gincrease (\ f x -> x)
>   plus a b                    =  Gincrease (\ f x -> case x of
>                                                 Inl l -> Inl (applyGincrease a f l)
>                                                 Inr r -> Inr (applyGincrease b f r))
>   prod a b                    =  Gincrease (\ f x -> (applyGincrease a f (outl x)) :*: (applyGincrease b f (outr x)))
>   view iso a                  =  Gincrease (\ f x -> to iso (applyGincrease a f (from iso x)))
>   int                         =  Gincrease (\ f x -> x)
>   char                        =  Gincrease (\ f x -> x)
>   float                       =  Gincrease (\ f x -> x)
> instance GenericCompany Gincrease where
>   salary                      =  Gincrease (\ f x -> incS f x)


> -- "interesting" code for increase
> incS :: Float -> Salary -> Salary
> incS k (S s) = S (s * (1+k))

> increase :: Float -> Company -> Company
> increase = applyGincrease over