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 
   15 
   16 data OpInverse x = OpInverse x x
   17     deriving (Eq, Ord, Show, Data, Functor, Traversable, Foldable, Typeable, Generic)
   18 
   19 instance Serialize x => Serialize (OpInverse x)
   20 instance Hashable  x => Hashable  (OpInverse x)
   21 instance ToJSON    x => ToJSON    (OpInverse x) where toJSON = genericToJSON jsonOptions
   22 instance FromJSON  x => FromJSON  (OpInverse x) where parseJSON = genericParseJSON jsonOptions
   23 
   24 instance (TypeOf x, Pretty x) => TypeOf (OpInverse x) where
   25     typeOf p@(OpInverse f g) = do
   26         ft <- typeOf f
   27         case ft of
   28           TypeFunction fFrom fTo -> do
   29             TypeFunction gFrom gTo <- typeOf g
   30             if typesUnify [fFrom, gTo] && typesUnify [fTo, gFrom]
   31                 then return TypeBool
   32                 else raiseTypeError p
   33           TypePermutation fi -> do
   34             TypePermutation gi <- typeOf g
   35             if typesUnify [fi,gi]
   36               then return TypeBool
   37               else raiseTypeError p
   38           _ -> raiseTypeError p 
   39 
   40 instance SimplifyOp OpInverse x where
   41     simplifyOp _ = na "simplifyOp{OpInverse}"
   42 
   43 instance Pretty x => Pretty (OpInverse x) where
   44     prettyPrec _ (OpInverse a b) = "inverse" <> prettyList prParens "," [a,b]
   45 
   46 instance VarSymBreakingDescription x => VarSymBreakingDescription (OpInverse x) where
   47     varSymBreakingDescription (OpInverse a b) = JSON.Object $ KM.fromList
   48         [ ("type", JSON.String "OpInverse")
   49         , ("children", JSON.Array $ V.fromList
   50             [ varSymBreakingDescription a
   51             , varSymBreakingDescription b
   52             ])
   53         ]