never executed always true always false

    1 {-# LANGUAGE DeriveGeneric, DeriveDataTypeable, DeriveFunctor, DeriveTraversable, DeriveFoldable #-}
    2 
    3 module Conjure.Language.Expression.Op.PreImage 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 OpPreImage x = OpPreImage x x
   15     deriving (Eq, Ord, Show, Data, Functor, Traversable, Foldable, Typeable, Generic)
   16 
   17 instance Serialize x => Serialize (OpPreImage x)
   18 instance Hashable  x => Hashable  (OpPreImage x)
   19 instance ToJSON    x => ToJSON    (OpPreImage x) where toJSON = genericToJSON jsonOptions
   20 instance FromJSON  x => FromJSON  (OpPreImage x) where parseJSON = genericParseJSON jsonOptions
   21 
   22 instance (TypeOf x, Pretty x) => TypeOf (OpPreImage x) where
   23     typeOf p@(OpPreImage f x) = do
   24         fTy <- typeOf f
   25         xTy <- typeOf x
   26         case fTy of
   27             TypeFunction from to -> do
   28                 if typesUnify [xTy, to]
   29                     then return (TypeSet from)
   30                     else raiseTypeError p
   31             TypeSequence to -> do
   32                 if typesUnify [xTy, to]
   33                     then return (TypeSet (TypeInt TagInt))
   34                     else raiseTypeError p
   35             _ -> raiseTypeError p
   36 
   37 instance SimplifyOp OpPreImage x where
   38     simplifyOp _ = na "simplifyOp{OpPreImage}"
   39 
   40 instance Pretty x => Pretty (OpPreImage x) where
   41     prettyPrec _ (OpPreImage a b) = "preImage" <> prettyList prParens "," [a,b]
   42 
   43 instance VarSymBreakingDescription x => VarSymBreakingDescription (OpPreImage x) where
   44     varSymBreakingDescription (OpPreImage a b) = JSON.Object $ KM.fromList
   45         [ ("type", JSON.String "OpPreImage")
   46         , ("children", JSON.Array $ V.fromList
   47             [ varSymBreakingDescription a
   48             , varSymBreakingDescription b
   49             ])
   50         ]