Definitions.hs

assemble :: Line -> AsmAct Word8 Word16 ()

assemble (Line labels Nothing) = sequence_ $ do
  l <- labels
  return $ (getPtr >>= setLabel l)

assemble (Line labels (Just (Instruction inst rawargs))) = do
  assemble (Line labels Nothing)
  args <- runListT $ do
    arg <- ListT $ return rawargs
    case arg of
      Label l -> do
        v <- lift $ getLabel l
        return $ Constant $ fromIntegral v
      _ -> return arg
  
  case (inst, args) of
    (Builtin "db", _) -> defineBytes args
    (Builtin "defb", _) -> defineBytes args
    (Builtin "dm", _) -> defineBytes args
    (Builtin "defm", _) -> defineBytes args
    
    (Builtin "adc", [Register "a", Constant x]) ->
      if fitsByte x
      then write [0xCE, fromIntegral x]
      else throwError "adc cannot handle constants larger than a byte"
    (Builtin "adc", [Register "a", Indirect (Register "hl")]) -> write [0x8E]
    (Builtin "adc", [Register "a", Register "a"]) -> write [0x8F]
    (Builtin "adc", [Register "a", Register "b"]) -> write [0x88]
    (Builtin "adc", [Register "a", Register "c"]) -> write [0x89]
    (Builtin "adc", [Register "a", Register "d"]) -> write [0x8A]
    (Builtin "adc", [Register "a", Register "e"]) -> write [0x8B]
    (Builtin "adc", [Register "a", Register "h"]) -> write [0x8C]
    (Builtin "adc", [Register "a", Register "l"]) -> write [0x8D]

    (Builtin "add", [Register "a", Constant x]) ->
      if fitsByte x
      then write [0xC6, fromIntegral x]
      else throwError "adc cannot handle constants larger than a byte"
    (Builtin "add", [Register "a", Indirect (Register "hl")]) -> write [0x86]
    (Builtin "add", [Register "a", Register "a"]) -> write [0x87]
    (Builtin "add", [Register "a", Register "b"]) -> write [0x80]
    (Builtin "add", [Register "a", Register "c"]) -> write [0x81]
    (Builtin "add", [Register "a", Register "d"]) -> write [0x82]
    (Builtin "add", [Register "a", Register "e"]) -> write [0x83]
    (Builtin "add", [Register "a", Register "h"]) -> write [0x84]
    (Builtin "add", [Register "a", Register "l"]) -> write [0x85]
    (Builtin "add", [Register "hl", Register "bc"]) -> write [0x09]
    (Builtin "add", [Register "hl", Register "de"]) -> write [0x19]
    (Builtin "add", [Register "hl", Register "hl"]) -> write [0x29]
    (Builtin "add", [Register "hl", Register "sp"]) -> write [0x39]
    (Builtin "add", [Register "sp", Constant x]) ->
      if fitsByte x
      then write [0xE8, fromIntegral x]
      else throwError "add cannot handle constants larger than a byte"

    (Builtin "and", [Constant x]) ->
      if fitsByte x
      then write [0xE6, fromIntegral x]
      else throwError "and cannot handle constants larger than a byte"
    (Builtin "and", [Indirect (Register "hl")]) -> write [0xA6]
    (Builtin "and", [Register "a"]) -> write [0xA7]
    (Builtin "and", [Register "b"]) -> write [0xA0]
    (Builtin "and", [Register "c"]) -> write [0xA1]
    (Builtin "and", [Register "d"]) -> write [0xA2]
    (Builtin "and", [Register "e"]) -> write [0xA3]
    (Builtin "and", [Register "h"]) -> write [0xA4]
    (Builtin "and", [Register "l"]) -> write [0xA5]
    
    (Macro name, _) -> throwError $ "invalid instruction " ++ name ++ " with args " ++ (show args)
    (Builtin name, _) -> throwError $ "invalid instruction " ++ name ++ " with args " ++ (show args)