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gyehoek-hs/src/Gyehoek/CPS/Eval.hs
T
2026-09-06 00:00:30 -06:00

304 lines
8.1 KiB
Haskell

{-# LANGUAGE ViewPatterns #-}
{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE OverloadedLists #-}
module Gyehoek.CPS.Eval
( evalProgram
, module Gyehoek.CPS.Syntax
, evalExp
, eGrammar
) where
import Gyehoek.CPS.Syntax hiding (Hob(..), Obj(..), cont)
import Gyehoek.Sexp qualified as S
import Control.Lens hiding (assign)
import Data.Maybe (fromMaybe, isJust)
import Text.Show.Functions ()
import qualified Data.HashMap.Strict as H
import Gyehoek.Prelude hiding (assign)
import Debug.Pretty.Simple
import Gyehoek.Jalmot
import Control.Monad.Cont
import Gyehoek.Sexp qualified as S
import GHC.Generics (Generically(..))
import Gyehoek.Sexp ((:-)(..))
import Data.List (nub, mapAccumR, compareLength)
import Data.HashSet.Lens (setOf)
import Data.IntMap.Strict (IntMap)
import Data.IntMap.Strict qualified as IM
import Data.Monoid
import Control.Monad.State
import Data.Traversable (for)
import Data.Foldable (traverse_, foldrM)
newtype Loc = MkLoc { getLoc :: Int }
deriving stock (Generic, Data)
deriving newtype (Show, Eq, Ord, Enum)
data Store = MkStore
{ nextLoc :: Loc
, heap :: IntMap E
}
deriving stock (Show, Generic)
type instance Index Store = Loc
type instance IxValue Store = E
instance Ixed Store where ix (MkLoc j) = #heap . ix j
instance At Store where at (MkLoc j) = #heap . at j
emptyStore :: Store
emptyStore = MkStore
{ nextLoc = MkLoc 0
, heap = mempty
}
newtype Env = MkEnv { getEnv :: HashMap Name Loc }
deriving stock (Show, Generic, Data)
deriving newtype (Semigroup, Monoid)
emptyEnv :: Env
emptyEnv = mempty
type instance Index Env = Name
type instance IxValue Env = Loc
instance Ixed Env where ix j = #getEnv . ix j
instance At Env where at j = #getEnv . at j
update :: Loc -> E -> Store -> Store
update (MkLoc loc) v = #heap %~ IM.alter f loc
where
f (Just _) = Just v
f Nothing = error "segfault lol"
updates :: Foldable f => f (Loc, E) -> Store -> Store
updates = alaf Endo foldMap (uncurry update)
fetch :: Loc -> M r E
fetch (MkLoc loc) = gets (^?! #heap . ix loc)
new :: M r Loc
new = state \st -> (st.nextLoc, st & #nextLoc %~ succ)
new' :: E -> M r Loc
new' e = state \st ->
( st.nextLoc
, st & #nextLoc %~ succ & at st.nextLoc ?~ e
)
defines :: Traversable t => t (Name, E) -> M Answer Env
defines = alaf Ap foldMap \(name,e) -> do
l <- new' e
pure $ bind name l
var :: HasCallStack => Env -> Name -> M Answer Loc
var g x = case g ^. at x of
Just l -> pure l
Nothing -> wrong [i|unbound variable #{x}|]
type CmdCont = Store -> Answer
type ExpCont = List E -> CmdCont
type M r = ContT r (State Store)
data Answer
= AnswerValues (List E)
| AnswerError AJalmot
deriving (Show, Generic)
data Mutability
= Mut
| NoMut
deriving (Show, Generic, Data, Eq)
wrong :: Text -> M Answer a
wrong s = ContT \_ -> pure . AnswerError . EvalError $ s
orWrong
:: Getting (First a) s a
-> Text -> s -> M Answer a
orWrong p msg s = case getFirst . getConst $ p (Const . First . Just) s of
Nothing -> wrong msg
Just x -> pure x
bind :: Name -> Loc -> Env
bind k = MkEnv . H.singleton k
extends :: Foldable f => f (Name, Loc) -> Env -> Env
extends xs g = g <> foldMap (uncurry bind) xs
assign :: Loc -> E -> M Answer ()
assign l e = do
use (at l) >>= \case
Just _ -> at l ?= e
Nothing -> wrong [i|#{e}에서 #{l}이라는 주소는 없다|]
-- | The denotation of an expressed value.
data E
= ESymbol Text
| ECharacter Char
| EInt Int
| EBool Bool
| EUndefined
| EUnspecified
| ENull
| EPair Mutability Loc Loc
| EVec Mutability (List Loc)
| EString Mutability (List Loc)
| EProcedure Procedure
deriving stock (Show, Generic)
type Procedure = List E -> DynPoints -> M Answer (List E)
eGrammar :: Store -> S.DatumGrammar E
eGrammar st = S.partialOsi (const . Left $ mempty) go
where
gofetch x = go $ st ^?! ix x
go = \case
ESymbol s -> S.Symbol s
ECharacter c -> S.Character c
EInt n -> S.Number (fromIntegral n)
EBool b -> S.Boolean b
EUndefined -> S.Unreadable "#<undefined>"
EUnspecified -> S.Unreadable "#<unspecified>"
EProcedure _ -> S.Unreadable "#<procedure>"
ENull -> S.List []
EPair _mut car cdr -> S.DotList [gofetch car] (gofetch cdr)
EVec _mut xs -> S.Vector . fmap gofetch $ xs
EString _mut xs -> S.String _
data DynPoints = MkDynPoints
deriving (Generic, Data)
truthy :: E -> Bool
truthy (EBool False) = False
truthy _ = True
evalVal :: Env -> Val -> M Answer E
evalVal g (ValVar x) = var g x >>= fetch
evalVal g (ValImm imm) = case imm of
ImmLabel (MkLabel l) -> var g l >>= fetch
ImmInt n -> pure $ EInt n
ImmBool b -> pure $ EBool b
ImmUndefined -> pure EUndefined
evalKexp :: Env -> Kexp -> M Answer E
evalKexp g (KexpVar x) = var g x >>= fetch
evalKexp g (KexpKappa kap) = evalAbs g (AbsKappa kap)
evalAbs :: Env -> Abs -> M Answer E
evalAbs g (MkAbs formals ktail e) = pure . EProcedure $ \xs dps ->
let
formals' = formals ++ foldMap (:[]) ktail
lformals = length formals'
lxs = length xs
in if lformals /= lxs
then wrong [i|함수는 #{lformals}개의 인자를 필요로 하는데 #{lxs} 받았다.|]
else do
ls <- xs & traverse new'
let g' = g & extends (zip formals' ls)
eval g' dps e
eval :: Env -> DynPoints -> Exp -> M Answer (List E)
eval g dps (ExpJump f xs ktail) = do
f' <- evalVal g f
xs' <- traverse (evalVal g) xs
ktail' <- traverse (evalKexp g) (ktail ^.. _Just)
case f' of
EProcedure p -> p (xs' ++ ktail') dps
_ -> wrong "bad procedure"
eval g dps (ExpLetRec bs e) = do
ls <- for bs . const $ new' EUndefined
let g' = g & extends (zip (bs ^.. each . _1) ls)
bs' <- forOf (each . _2) bs (evalAbs g')
traverse_ (uncurry assign) $ zip ls (bs' ^.. each . _2)
eval g' dps e
eval g dps (ExpPrim (PrimCallCC withcc) k) = do
withcc' <- evalVal g withcc >>= orWrong #_EProcedure
[i|call/cc: 함수가 아닌 것을 받았다|]
k' <- evalKexp g k
kproc <- orWrong #_EProcedure [i|call/cc: 몰라...|] k'
let cc = EProcedure \xs dps -> case unsnoc xs of
Just (xs',_) -> kproc xs' dps
Nothing -> wrong [i|call/cc: 잘못하는데!|]
withcc' [cc,k'] dps
eval g dps (ExpPrim p k) = do
p' <- evalPrim g dps =<< traverse (evalVal g) p
evalKexp g k >>= \case
EProcedure fp -> fp p' dps
_ -> wrong [i|prim(#{p}) 계속을 나쁘다|]
eval g dps (ExpIf c t f) = do
c' <- evalVal g c
let b = if truthy c' then t else f
var g b >>= fetch >>= \case
EProcedure fp -> fp [] dps
_ -> wrong [i|if의 계속을 나쁘다|]
eval g dps e = error [i|unimplemented #{e}|]
evalPrim :: Env -> DynPoints -> Prim E -> M Answer (List E)
evalPrim g dps = \case
PrimAdd x y -> arith2 (+) x y
PrimMul x y -> arith2 (*) x y
PrimSub x y -> arith2 (-) x y
PrimDiv x y -> arith2 div x y
PrimZeroP x -> pure1 . EBool . isJust $ x ^? #EInt . only 0
PrimCons x y -> pcons x y >>= pure1
PrimCar p -> cr p _2
PrimCdr p -> cr p _3
PrimPairP p -> pure1 . EBool . maybe False (const True) $
p ^? #_EPair
PrimValues xs -> pure xs
PrimList xs -> foldrM pcons ENull xs >>= pure1
p -> wrong [i|prim(#{p}) 벌써 나지 않다|]
where
pure1 x = pure [x]
pcons x y = do
(x',y') <- traverseOf both new' (x,y)
pure $ EPair Mut x' y'
arith2 f (EInt x) (EInt y) = pure [EInt $ f x y]
arith2 f x y = wrong [i|나쁜 인자: #{x}, #{y}|]
cr p l = orWrong (#_EPair . l) [i|car/cdr는 pair을 받지 않다|] p
>>= fmap (:[]) . fetch
evalExp :: Jalmot :> es => Exp -> Eff es _
evalExp e = _
evalProgram :: Jalmot :> es => Program -> Eff es (List S.Datum)
evalProgram (MkProgram lam) = case run (pure . AnswerValues) of
(AnswerError jm, _) -> throwError jm
(AnswerValues vs, st) -> traverse (S.toDatum $ eGrammar st) vs
where
run f = (`runState` emptyStore) . (`runContT` f) $ do
g <- setup
eval g MkDynPoints (ExpLetRec
[("_start",AbsLambda lam)]
(ExpApply (ValVar "_start") [] (KexpVar "halt")))
setup :: M Answer Env
setup = defines @List
[ ("halt", EProcedure prim_halt)
]
prim_halt :: Procedure
prim_halt xs _dps = ContT \_ -> pure $ AnswerValues xs