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module Compiler where
import Data.Char (isUpper)
import qualified Data.Map as M
import Code (Code, Datum(..), Heap, Instr(..), heapStruct)
import IR (Id(..), PrlgInt(..), StrTable(..))
desugarPrlg :: Int -> PrlgInt -> PrlgInt
desugarPrlg list = go
where
go (CallI id ps) = CallI id $ map go ps
go (ListI (x:xs) t) = CallI list [go x, go (ListI xs t)]
go (ListI [] Nothing) = AtomI list
go (ListI [] (Just x)) = go x
go x = x
varname :: String -> Bool
varname ('_':_) = True
varname (c:_) = isUpper c
varname _ = False
varOccurs :: PrlgInt -> M.Map Int Int
varOccurs (CallI _ xs) = M.unionsWith (+) $ map varOccurs xs
varOccurs (VarI idx _) = M.singleton idx 1
varOccurs _ = M.empty
variablizePrlg :: Int -> StrTable -> PrlgInt -> PrlgInt
variablizePrlg void (StrTable _ _ itos) = go
where
go (CallI i ps) = CallI i $ map go ps
go (AtomI i)
| i == void = VoidI
| varname (itos M.! i) = VarI i i
| otherwise = AtomI i
go x = x
renumVars :: (Int -> Maybe PrlgInt) -> PrlgInt -> PrlgInt
renumVars rename = go
where
go (CallI i ps) = CallI i $ map go ps
go (VarI idx i)
| Just new <- rename idx = new
go x = x
squashVars :: PrlgInt -> PrlgInt
squashVars x =
let occurs = M.assocs (varOccurs x)
m' =
M.fromList $
[(idx, VoidI) | (idx, n) <- occurs, n <= 1] ++
[(idx, VarI idx' 0) | ((idx, n), idx') <- zip occurs [1 ..], n > 1]
in renumVars (m' M.!?) x
compileGoals :: Int -> Int -> PrlgInt -> [Code]
compileGoals andop cut = go'
where
go' = go . struct2goal
go p@(CallI x args@[_, _])
| x == andop = concatMap go' args
go p@(CallI x [])
| x == cut = [[Cut]]
go x = [compileGoal x]
compileGoal :: PrlgInt -> Code
compileGoal = compileArg . struct2goal
compileArg :: PrlgInt -> Code
compileArg (CallI i args) =
U (Struct Id {str = i, arity = length args}) : concatMap compileArg args
compileArg (AtomI s) = [U (Atom s)]
compileArg (NumI s) = [U (Number s)]
compileArg (VarI x _) = [U (LocalRef x)]
compileArg (VoidI) = [U VoidRef]
seqGoals :: [Code] -> Code
seqGoals [] = [NoGoal]
seqGoals [[Cut]] = [Cut, NoGoal]
seqGoals [x] = [Goal] ++ x ++ [LastCall]
seqGoals [x, [Cut]] = [Goal] ++ x ++ [LastCall, Cut]
seqGoals ([Cut]:xs) = [Cut] ++ seqGoals xs
seqGoals (x:xs) = [Goal] ++ x ++ [Call] ++ seqGoals xs
heapStructPrlgInt :: Monad m => m PrlgInt -> Heap -> Int -> m PrlgInt
heapStructPrlgInt heaperr heap ref = heapStruct atom struct hrec heap ref
where
atom (Atom s) = pure $ AtomI s
atom (Number n) = pure $ NumI n
atom VoidRef = pure $ VoidI
struct (Struct s) args = pure $ CallI (str s) args
hrec (HeapRef r) ref
| r == ref = pure $ VarI r 0
| otherwise = heaperr
-- TODO check if this is used
goal2struct :: PrlgInt -> PrlgInt
goal2struct (CallI s []) = AtomI s
goal2struct x = x
struct2goal :: PrlgInt -> PrlgInt
struct2goal (AtomI s) = CallI s []
struct2goal x = x
|
