never executed always true always false

    1 {-# LANGUAGE DeriveGeneric, DeriveDataTypeable, DeriveFunctor, DeriveTraversable, DeriveFoldable #-}
    2 
    3 module Conjure.Language.Expression.Op.Iff 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 OpIff x = OpIff x x
   15     deriving (Eq, Ord, Show, Data, Functor, Traversable, Foldable, Typeable, Generic)
   16 
   17 instance Serialize x => Serialize (OpIff x)
   18 instance Hashable  x => Hashable  (OpIff x)
   19 instance ToJSON    x => ToJSON    (OpIff x) where toJSON = genericToJSON jsonOptions
   20 instance FromJSON  x => FromJSON  (OpIff x) where parseJSON = genericParseJSON jsonOptions
   21 
   22 instance BinaryOperator (OpIff x) where
   23     opLexeme _ = L_Iff
   24 
   25 instance (TypeOf x, Pretty x) => TypeOf (OpIff x) where
   26     typeOf p@(OpIff a b) = boolToBoolToBool p a b
   27 
   28 instance SimplifyOp OpIff x where
   29     simplifyOp (OpIff a b)
   30         | fromBool True == a = return b
   31         | fromBool True == b = return a
   32     simplifyOp _ = na "simplifyOp{OpIff}"
   33 
   34 instance Pretty x => Pretty (OpIff x) where
   35     prettyPrec prec op@(OpIff a b) = prettyPrecBinOp prec [op] a b
   36 
   37 instance VarSymBreakingDescription x => VarSymBreakingDescription (OpIff x) where
   38     varSymBreakingDescription (OpIff a b) = JSON.Object $ KM.fromList
   39         [ ("type", JSON.String "OpIff")
   40         , ("children", JSON.Array $ V.fromList
   41             [ varSymBreakingDescription a
   42             , varSymBreakingDescription b
   43             ])
   44         , ("symmetricChildren", JSON.Bool True)
   45         ]