Build with stack

1 files changed, 73 insertions, 0 deletions

diff --git a/AST.hs b/AST.hs
new file mode 100644
index 0000000..cd7fed2
--- /dev/null
+++ b/AST.hs
@@ -0,0 +1,73 @@
+module AST where
+
+import Data.List
+import Data.Word
+
+
+type Byte = Word8
+type Offset = Int
+
+
+newtype Program = Program [Instruction]
+  deriving (Show, Eq)
+
+data Instruction
+    = IAdd Byte Offset
+    | ISet Byte Offset
+    | ICopy Offset Offset Byte  -- ICopy from to multiplier
+    | ISlide Offset
+    | ILoop [Instruction] Offset
+    | IInput Offset
+    | IOutput Offset
+    | IStart
+  deriving (Show, Eq)
+
+isIAdd :: Instruction -> Bool
+isIAdd (IAdd _ _) = True
+isIAdd _ = False
+
+isISet :: Instruction -> Bool
+isISet (ISet _ _) = True
+isISet _ = False
+
+isICopy :: Instruction -> Bool
+isICopy (ICopy _ _ _) = True
+isICopy _ = False
+
+isISlide :: Instruction -> Bool
+isISlide (ISlide _) = True
+isISlide _ = False
+
+isIStart :: Instruction -> Bool
+isIStart IStart = True
+isIStart _ = False
+
+offsetOf :: Instruction -> Offset
+offsetOf (IAdd _ o) = o
+offsetOf (ISet _ o) = o
+offsetOf (ICopy o _ _) = o
+offsetOf (ISlide _) = undefined
+offsetOf (ILoop _ _) = undefined
+offsetOf (IInput o) = o
+offsetOf (IOutput o) = o
+offsetOf IStart = 0
+
+astSuccinct :: Program -> String
+astSuccinct (Program inss) = intercalate " " $ map insSuccinct inss
+  where
+    insSuccinct :: Instruction -> String
+    insSuccinct (IAdd v o) =
+        let sv = signedByte v
+        in (if sv >= 0 then "+" else "") ++ show (signedByte v) ++ ',' : show o
+    insSuccinct (ISet v o) = '=' : show (signedByte v) ++ ',' : show o
+    insSuccinct (ICopy from to v) = 'C' : show from ++ ',' : show to ++ ',' : show v
+    insSuccinct (ISlide o) = '>' : show o
+    insSuccinct (ILoop inss' off) = "[(" ++ show off ++ ')' : intercalate " " (map insSuccinct inss') ++ "]"
+    insSuccinct (IInput o) = ',' : show o
+    insSuccinct (IOutput o) = '.' : show o
+    insSuccinct IStart = "$"
+
+    signedByte :: Byte -> Int
+    signedByte v
+        | v < 128 = fromIntegral v
+        | otherwise = fromIntegral v - 256