never executed always true always false

    1 module HelVM.HelMA.Automata.BrainFuck.Common.Symbol
    2   ( Symbol
    3   , compare0
    4   , def
    5   , fromChar
    6   , inc
    7   , next
    8   , prev
    9   , toChar
   10   , toInteger
   11   ) where
   12 
   13 import           Data.Default ( Default )
   14 
   15 import qualified Data.Default as Default
   16 import qualified Relude.Extra as Extra
   17 
   18 inc ∷ Symbol e ⇒ e → e → e
   19 inc = flip (+)
   20 
   21 compare0 ∷ Integer → Ordering
   22 compare0 = compare 0
   23 
   24 --
   25 
   26 def ∷ Symbol e ⇒ e
   27 def = Default.def
   28 
   29 next ∷ Symbol e ⇒ e → e
   30 next = Extra.next
   31 
   32 prev ∷ Symbol e ⇒ e → e
   33 prev = Extra.prev
   34 
   35 class (Bounded e , Default e , Enum e , Eq e , Integral e , Show e) => Symbol e where
   36 --  toInteger  :: e -> Integer
   37   fromChar   :: Char → e
   38   toChar     :: e → Char
   39 
   40 --
   41 
   42 instance Symbol Int where
   43 --  toInteger  = fromIntegral
   44   fromChar   = ord
   45   toChar     = chr
   46 
   47 instance Symbol Word where
   48 --  toInteger  = fromIntegral
   49   fromChar   = fromIntegral . ord
   50   toChar     = chr . fromIntegral
   51 
   52 instance Symbol Int8 where
   53 --  toInteger  = fromIntegral
   54   fromChar   = fromIntegral . ord
   55   toChar     = chr . normalizeMod . fromIntegral
   56 
   57 instance Symbol Word8 where
   58 --  toInteger  = fromIntegral
   59   fromChar   = fromIntegral . ord
   60   toChar     = chr . fromIntegral
   61 
   62 instance Symbol Int16 where
   63 --  toInteger  = fromIntegral
   64   fromChar   = fromIntegral . ord
   65   toChar     = chr . normalizeMod . fromIntegral
   66 
   67 instance Symbol Word16 where
   68 --  toInteger  = fromIntegral
   69   fromChar   = fromIntegral . ord
   70   toChar     = chr . fromIntegral
   71 
   72 instance Symbol Int32 where
   73 --  toInteger  = fromIntegral
   74   fromChar   = fromIntegral . ord
   75   toChar     = chr . normalizeMod . fromIntegral
   76 
   77 instance Symbol Word32 where
   78 --  toInteger  = fromIntegral
   79   fromChar   = fromIntegral . ord
   80   toChar     = chr . fromIntegral
   81 
   82 instance Symbol Int64 where
   83 --  toInteger  = fromIntegral
   84   fromChar   = fromIntegral . ord
   85   toChar     = chr . normalizeMod . fromIntegral
   86 
   87 instance Symbol Word64 where
   88 --  toInteger  = fromIntegral
   89   fromChar   = fromIntegral . ord
   90   toChar     = chr . fromIntegral
   91 --
   92 
   93 countSymbols ∷ (Integral e) ⇒ e
   94 countSymbols = 256
   95 
   96 modifyMod ∷ (Integral e) ⇒ (e → e) → e → e
   97 modifyMod f i = f (i + countSymbols) `mod` countSymbols
   98 
   99 normalizeMod ∷ (Integral e) ⇒ e → e
  100 normalizeMod = modifyMod id