never executed always true always false

    1 module HelVM.HelMA.Automata.BrainFuck.Impl.Flat.Instruction where
    2 
    3 import           HelVM.HelMA.Automata.BrainFuck.Common.SimpleInstruction
    4 
    5 import           Text.Read
    6 
    7 import qualified Text.Show
    8 
    9 data FlatInstruction =
   10     Simple SimpleInstruction
   11   | JmpPast
   12   | JmpBack
   13   deriving stock (Eq)
   14 
   15 type FlatTreeInstructionList = [FlatInstruction]
   16 
   17 instance Show FlatInstruction where
   18   show (Simple i) = show i
   19   show JmpPast    = "["
   20   show JmpBack    = "]"
   21 
   22 instance Read FlatInstruction where
   23   readsPrec _ ">" = [( Simple MoveR  , "")]
   24   readsPrec _ "<" = [( Simple MoveL  , "")]
   25   readsPrec _ "+" = [( Simple Inc    , "")]
   26   readsPrec _ "-" = [( Simple Dec    , "")]
   27   readsPrec _ "." = [( Simple Output , "")]
   28   readsPrec _ "," = [( Simple Input  , "")]
   29   readsPrec _ "[" = [( JmpPast       , "")]
   30   readsPrec _ "]" = [( JmpBack       , "")]
   31   readsPrec _ _   = []