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    1 {-# LANGUAGE DeriveGeneric, DeriveDataTypeable, DeriveFunctor, DeriveTraversable, DeriveFoldable #-}
    2 
    3 module Conjure.Language.Expression.Op.Factorial where
    4 
    5 import Conjure.Prelude
    6 import Conjure.Language.Expression.Op.Internal.Common
    7 
    8 import qualified Data.Aeson as JSON             -- aeson
    9 import qualified Data.Aeson.KeyMap as KM
   10 
   11 import qualified Data.Vector as V               -- vector
   12 
   13 
   14 data OpFactorial x = OpFactorial x
   15     deriving (Eq, Ord, Show, Data, Functor, Traversable, Foldable, Typeable, Generic)
   16 
   17 instance Serialize x => Serialize (OpFactorial x)
   18 instance Hashable  x => Hashable  (OpFactorial x)
   19 instance ToJSON    x => ToJSON    (OpFactorial x) where toJSON = genericToJSON jsonOptions
   20 instance FromJSON  x => FromJSON  (OpFactorial x) where parseJSON = genericParseJSON jsonOptions
   21 
   22 instance (TypeOf x, Pretty x) => TypeOf (OpFactorial x) where
   23     typeOf p@(OpFactorial a) = do
   24         TypeInt t <- typeOf a
   25         case t of
   26             TagInt -> return ()
   27             _ -> raiseTypeError p
   28         return (TypeInt t)
   29 
   30 instance SimplifyOp OpFactorial x where
   31     simplifyOp _ = na "simplifyOp{OpFactorial}"
   32 
   33 instance Pretty x => Pretty (OpFactorial x) where
   34     prettyPrec _ (OpFactorial a) = "factorial" <> prParens (pretty a)
   35 
   36 instance VarSymBreakingDescription x => VarSymBreakingDescription (OpFactorial x) where
   37     varSymBreakingDescription (OpFactorial a) = JSON.Object $ KM.fromList
   38         [ ("type", JSON.String "OpFactorial")
   39         , ("children", JSON.Array $ V.fromList
   40             [ varSymBreakingDescription a
   41             ])
   42         ]