never executed always true always false

    1 {-# LANGUAGE DeriveGeneric, DeriveDataTypeable, DeriveFunctor, DeriveTraversable, DeriveFoldable #-}
    2 
    3 module Conjure.Language.Expression.Op.Pred 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 OpPred x = OpPred x
   15     deriving (Eq, Ord, Show, Data, Functor, Traversable, Foldable, Typeable, Generic)
   16 
   17 instance Serialize x => Serialize (OpPred x)
   18 instance Hashable  x => Hashable  (OpPred x)
   19 instance ToJSON    x => ToJSON    (OpPred x) where toJSON = genericToJSON jsonOptions
   20 instance FromJSON  x => FromJSON  (OpPred x) where parseJSON = genericParseJSON jsonOptions
   21 
   22 instance (TypeOf x, Pretty x) => TypeOf (OpPred x) where
   23     typeOf p@(OpPred x) = do
   24         ty <- typeOf x
   25         case ty of
   26             TypeBool{} -> return ty
   27             TypeInt TagInt  -> return ty
   28             TypeInt (TagEnum _)  -> return ty
   29             TypeEnum{} -> return ty
   30             _ -> raiseTypeError p
   31 
   32 instance SimplifyOp OpPred x where
   33     simplifyOp _ = na "simplifyOp{OpPred}"
   34 
   35 instance Pretty x => Pretty (OpPred x) where
   36     prettyPrec _ (OpPred x) = "pred" <> prParens (pretty x)
   37 
   38 instance VarSymBreakingDescription x => VarSymBreakingDescription (OpPred x) where
   39     varSymBreakingDescription (OpPred a) = JSON.Object $ KM.fromList
   40         [ ("type", JSON.String "OpPred")
   41         , ("children", JSON.Array $ V.fromList
   42             [ varSymBreakingDescription a
   43             ])
   44         ]