never executed always true always false

    1 {-# LANGUAGE DeriveGeneric, DeriveDataTypeable, DeriveFunctor, DeriveTraversable, DeriveFoldable #-}
    2 
    3 module Conjure.Language.Expression.Op.Inverse 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 OpInverse x = OpInverse x x
   15     deriving (Eq, Ord, Show, Data, Functor, Traversable, Foldable, Typeable, Generic)
   16 
   17 instance Serialize x => Serialize (OpInverse x)
   18 instance Hashable  x => Hashable  (OpInverse x)
   19 instance ToJSON    x => ToJSON    (OpInverse x) where toJSON = genericToJSON jsonOptions
   20 instance FromJSON  x => FromJSON  (OpInverse x) where parseJSON = genericParseJSON jsonOptions
   21 
   22 instance (TypeOf x, Pretty x) => TypeOf (OpInverse x) where
   23     typeOf p@(OpInverse f g) = do
   24         TypeFunction fFrom fTo <- typeOf f
   25         TypeFunction gFrom gTo <- typeOf g
   26         if typesUnify [fFrom, gTo] && typesUnify [fTo, gFrom]
   27             then return TypeBool
   28             else raiseTypeError p
   29 
   30 instance SimplifyOp OpInverse x where
   31     simplifyOp _ = na "simplifyOp{OpInverse}"
   32 
   33 instance Pretty x => Pretty (OpInverse x) where
   34     prettyPrec _ (OpInverse a b) = "inverse" <> prettyList prParens "," [a,b]
   35 
   36 instance VarSymBreakingDescription x => VarSymBreakingDescription (OpInverse x) where
   37     varSymBreakingDescription (OpInverse a b) = JSON.Object $ KM.fromList
   38         [ ("type", JSON.String "OpInverse")
   39         , ("children", JSON.Array $ V.fromList
   40             [ varSymBreakingDescription a
   41             , varSymBreakingDescription b
   42             ])
   43         ]