never executed always true always false

    1 {-# LANGUAGE DeriveGeneric, DeriveDataTypeable, DeriveFunctor, DeriveTraversable, DeriveFoldable #-}
    2 {-# LANGUAGE UndecidableInstances #-}
    3 
    4 module Conjure.Language.Expression.Op.TwoBars where
    5 
    6 import Conjure.Prelude
    7 import Conjure.Language.Expression.Op.Internal.Common
    8 
    9 import qualified Data.Aeson as JSON             -- aeson
   10 import qualified Data.Aeson.KeyMap as KM
   11 
   12 import qualified Data.Vector as V               -- vector
   13 
   14 
   15 data OpTwoBars x = OpTwoBars x
   16     deriving (Eq, Ord, Show, Data, Functor, Traversable, Foldable, Typeable, Generic)
   17 
   18 instance Serialize x => Serialize (OpTwoBars x)
   19 instance Hashable  x => Hashable  (OpTwoBars x)
   20 instance ToJSON    x => ToJSON    (OpTwoBars x) where toJSON = genericToJSON jsonOptions
   21 instance FromJSON  x => FromJSON  (OpTwoBars x) where parseJSON = genericParseJSON jsonOptions
   22 
   23 instance (TypeOf x, Pretty x, Domain () x :< x) => TypeOf (OpTwoBars x) where
   24     typeOf p@(OpTwoBars a) = do
   25         case project a of
   26             Just (_ :: Domain () x) -> return ()
   27             Nothing -> do
   28                 ty <- typeOf a
   29                 case ty of
   30                     TypeInt _       -> return ()
   31                     TypeList{}      -> return ()
   32                     TypeMatrix{}    -> return ()
   33                     TypeSet{}       -> return ()
   34                     TypeMSet{}      -> return ()
   35                     TypeFunction{}  -> return ()
   36                     TypeSequence{}  -> return ()
   37                     TypeRelation{}  -> return ()
   38                     TypePartition{} -> return ()
   39                     _               -> raiseTypeError $ vcat [ pretty p
   40                                                              , "Expected an integer or a collection."
   41                                                              , "But got:" <+> pretty ty
   42                                                              ]
   43         return $ TypeInt TagInt
   44 
   45 instance SimplifyOp OpTwoBars x where
   46     simplifyOp _ = na "simplifyOp{OpTwoBars}"
   47 
   48 instance Pretty x => Pretty (OpTwoBars x) where
   49     prettyPrec _ (OpTwoBars a) = "|" <> pretty a <> "|"
   50 
   51 instance VarSymBreakingDescription x => VarSymBreakingDescription (OpTwoBars x) where
   52     varSymBreakingDescription (OpTwoBars a) = JSON.Object $ KM.fromList
   53         [ ("type", JSON.String "OpTwoBars")
   54         , ("children", JSON.Array $ V.fromList
   55             [ varSymBreakingDescription a
   56             ])
   57         ]