sem.icl

   1 implementation module sem
   2
   3 import qualified Data.Map as Map
   4 from Data.Func import $
   5 import Data.Maybe
   6 import Data.Void
   7 import Data.Either
   8 import Data.Functor
   9 import Control.Applicative
  10 import Control.Monad
  11 import Control.Monad.State
  12 import Control.Monad.Identity
  13 import Math.Random
  14 import Control.Monad.Trans
  15 import StdMisc
  16 from StdFunc import id, const, o
  17 import StdString
  18 import StdTuple
  19 import StdList
  20 import StdBool
  21 import GenEq
  22
  23 from Text import class Text(concat), instance Text String
  24
  25 import AST
  26
  27 :: Gamma :== ('Map'.Map String Type, [String])
  28 :: Env a :== StateT Gamma (Either SemError) a
  29 //StateT (Gamma -> Either SemError (a, Gamma))
  30
  31 //we need to redefine this even though it is in Control.Monad.State
  32 instance MonadTrans (StateT Gamma) where
  33     liftT m = StateT \s-> m >>= \a-> return (a, s)
  34
  35 get :== gets id
  36
  37 sem :: AST -> SemOutput
  38 sem (AST vd fd) = case runStateT m ('Map'.newMap, getRandomStream 1) of
  39     Left e = Left [e]
  40     Right ((vds, fds), gamma) = Right ((AST vds fds), gamma)
  41 where
  42     m :: Env ([VarDecl], [FunDecl])
  43     m = mapM semVarDecl vd >>= \vd1 ->
  44         mapM semFunDecl fd >>= \fd1 ->
  45         mapM semVarDecl vd1 >>= \vd2 ->
  46         mapM semFunDecl fd1 >>= \fd2 ->
  47         mapM semVarDecl vd2 >>= \vd3 ->
  48         mapM semFunDecl fd2 >>= \fd3 ->
  49         mapM semVarDecl vd3 >>= \vd4 ->
  50         mapM semFunDecl fd3 >>= \fd4 ->  //Dit is puur om te proberen
  51         pure (vd4, fd4)
  52
  53 semFunDecl :: FunDecl -> Env FunDecl
  54 semFunDecl fd=:(FunDecl p f args mt vds stmts) =
  55     (case mt of
  56         Nothing = genType args >>= \infft->putIdent f infft >>| pure infft
  57         Just t = putIdent f t >>| pure t) >>= \ft ->
  58     saveGamma >>= \gamma ->
  59         matchFunctions args ft >>= \tres->
  60     mapM semVarDecl vds >>= \newvds->
  61     mapM (checkStmt tres) stmts >>= \newstmts->
  62         inferReturnType stmts >>= \returntype`->
  63         unify returntype` tres >>= \returntype->
  64         case mt of
  65                 Nothing = reconstructType args tres
  66                         >>= \ftype`->recoverType ftype`
  67                         >>= \ftype->restoreGamma gamma
  68                         >>| putIdent f ftype >>| pure (
  69                         FunDecl p f args (Just ftype) newvds newstmts)
  70                 Just t = restoreGamma gamma >>| updateFunType t returntype
  71                         >>= \tt-> pure (FunDecl p f args (Just tt) newvds newstmts)
  72
  73 recoverType :: Type -> Env Type
  74 recoverType (IdType ident) = gets (\(st, r)->'Map'.get ident st)
  75         >>= \mt->case mt of
  76                 Nothing = pure (IdType ident)
  77                 Just t = pure t
  78 recoverType (t1 ->> t2) = recoverType t1 >>= \t1`->recoverType t2
  79         >>= \t2`->pure (t1` ->> t2`)
  80 recoverType t = pure t
  81
  82 updateFunType :: Type Type -> Env Type
  83 updateFunType (t1 ->> t2) t3 = updateFunType t2 t3 >>= \t2`->pure $ t1 ->> t2`
  84 updateFunType t1 t2 = unify t1 t2
  85
  86 inferReturnType :: [Stmt] -> Env Type
  87 inferReturnType [] = pure VoidType
  88 inferReturnType [ReturnStmt (Just t):rest] = typeExpr t
  89         >>= \tx->inferReturnType rest >>= \ty->unify tx ty
  90 inferReturnType [ReturnStmt _:rest] =
  91         inferReturnType rest >>= \tx-> unify VoidType tx
  92 inferReturnType [_:rest] = inferReturnType rest
  93
  94 reconstructType :: [String] Type -> Env Type
  95 reconstructType [] t = pure t
  96 reconstructType [x:xs] t = gets (\(st, r)->'Map'.get x st)
  97         >>= \mtype->case mtype of
  98                 Nothing = liftT $ Left $ Error "Not used ????"
  99                 Just type = reconstructType xs t >>= \resttype->pure (type ->> resttype)
 100
 101 genType :: [String] -> Env Type
 102 genType [] = freshIdent >>= \fi->pure $ IdType fi
 103 genType [x:xs] = liftM2 (->>) (freshIdent >>= \fi->pure $ IdType fi)
 104         (genType xs)
 105
 106 matchFunctions :: [String] Type -> Env Type
 107 matchFunctions [] (_ ->> _) = liftT $ Left $
 108         ArgumentMisMatchError zero "Not enough arguments"
 109 matchFunctions _ (VoidType ->> _) = liftT $ Left $
 110         ArgumentMisMatchError zero "Void can't be a non return type"
 111 matchFunctions [x:xs] (t1 ->> t2) =
 112         modify (\(st, r)->('Map'.put x t1 st, r)) >>| matchFunctions xs t2
 113 matchFunctions [] t = pure t
 114 matchFunctions _ t = liftT $ Left $
 115         ArgumentMisMatchError zero "Too much argumnts"
 116
 117 semVarDecl :: VarDecl -> Env VarDecl
 118 semVarDecl (VarDecl pos type ident ex) = unify type ex
 119     >>= \t-> putIdent ident t >>| (pure $ VarDecl pos t ident ex)
 120
 121 checkStmt ::Type Stmt -> Env Stmt
 122 checkStmt t (IfStmt c st se) = unify BoolType c >>| mapM (checkStmt t) st
 123     >>= \st1-> mapM (checkStmt t) se >>= \se1-> pure (IfStmt c st1 se1)
 124 checkStmt t w=:(WhileStmt c et) = unify BoolType c >>| mapM (checkStmt t) et
 125     >>= \et1-> pure w
 126 checkStmt t a=:(AssStmt (VarDef ident fs) e) = gets (\(st, r)->'Map'.get ident st)
 127     >>= \mt->case mt of
 128         Nothing = liftT $ Left $ UndeclaredVariableError zero ident
 129         Just t = unify t fs >>= \t1 -> unify t1 e >>| pure a
 130 checkStmt t r=:(FunStmt (FunCall f es)) = typeFun f es >>| pure r
 131 checkStmt VoidType r=:(ReturnStmt Nothing) = pure r
 132 checkStmt t r=:(ReturnStmt (Just e)) = unify t e >>| pure r
 133
 134 typeExpr :: Expr -> Env Type
 135 typeExpr (IntExpr _ _) = pure IntType
 136 typeExpr (CharExpr _ _) = pure CharType
 137 typeExpr (BoolExpr _ _) = pure BoolType
 138 typeExpr (Op1Expr p UnNegation expr) = unify BoolType expr
 139 typeExpr (Op1Expr p UnMinus expr) = unify IntType expr
 140 typeExpr (TupleExpr p (e1, e2)) = typeExpr e1
 141     >>= \t1-> typeExpr e2 >>= \t2-> pure $ TupleType (t1, t2)
 142 typeExpr (Op2Expr p e1 op e2)
 143 | isMember op [BiPlus, BiMinus, BiTimes, BiDivide, BiMod] =
 144         typeOp2 e1 e2 op [IntType] IntType
 145 | isMember op [BiEquals, BiUnEqual] =
 146         typeOp2 e1 e2 op [IntType, BoolType, CharType] BoolType
 147 | isMember op [BiLesser, BiGreater, BiLesserEq, BiGreaterEq] =
 148         typeOp2 e1 e2 op [IntType, CharType] BoolType
 149 | isMember op [BiAnd, BiOr] =
 150         typeOp2 e1 e2 op [BoolType] BoolType
 151 | op == BiCons = typeExpr e1 >>= \t1-> typeExpr e2
 152         >>= \t2-> unify (ListType t1) t2
 153 typeExpr (EmptyListExpr p) = freshIdent >>= \frsh-> let t = IdType frsh in
 154     putIdent frsh t >>| pure t
 155 typeExpr (FunExpr p (FunCall f es)) = typeFun f es
 156 typeExpr (VarExpr p (VarDef ident fs)) = gets (\(st, r)->'Map'.get ident st)
 157     >>= \mt->case mt of
 158         Nothing = liftT $ Left $ UndeclaredVariableError p ident
 159         Just t = unify t fs
 160 typeOp2 :: Expr Expr Op2 [Type] Type -> Env Type
 161 typeOp2 e1 e2 op ts ret = typeExpr e1 >>= \t1-> typeExpr e2 >>= \t2->
 162     unify t1 t2 >>= \t3->if (isMember t3 [IdType "":ts]) (pure ret)
 163         (liftT $ Left $ OperatorError (extrPos e1) op t3)
 164
 165 buildFunctionType :: String [Expr] -> Env Type
 166 buildFunctionType frsh [] = let t = IdType frsh in putIdent frsh t >>| pure t
 167 buildFunctionType frsh [e:es] = (->>) <$> typeExpr e <*> buildFunctionType frsh es
 168
 169 unifyApp :: Type [Expr] -> Env Type
 170 unifyApp t [] = pure t
 171 unifyApp (tf1 ->> tf2) [t1:ts] = unify tf1 t1 >>| unifyApp tf2 ts
 172 unifyApp t1 t2 = liftT $ Left $ UnifyError zero t1 (IdType "[expressions, FIXME]")
 173
 174 typeFun :: String [Expr] -> Env Type
 175 typeFun f es = gets (\(st, r)->'Map'.get f st) >>= \mt-> case mt of
 176     Nothing = freshIdent >>= \frsh-> buildFunctionType frsh es
 177         >>= \ft-> putIdent f ft >>| (pure $ IdType frsh)
 178     Just t = unifyApp t es
 179
 180 resultType :: Type -> Type
 181 resultType (_ ->> t) = resultType t
 182 resultType t = t
 183
 184 class unify a :: Type a -> Env Type
 185
 186 instance unify [FieldSelector] where
 187     unify t [] = pure t
 188     unify (ListType t) [FieldHd:fs] = unify t fs
 189     unify t=:(ListType _) [FieldTl:fs] = unify t fs
 190     unify (TupleType (t, _)) [FieldFst:fs] = unify t fs
 191     unify (TupleType (_, t)) [FieldSnd:fs] = unify t fs
 192     unify t [fs:_] = liftT $ Left $ FieldSelectorError zero t fs
 193
 194 instance unify Expr where
 195         unify (_ ->> _) e = liftT $ Left $ ParseError (extrPos e)
 196                         "Expression cannot be a higher order function. Yet..."
 197         unify VoidType e = liftT $ Left $ ParseError (extrPos e)
 198                         "Expression cannot be a Void type."
 199 //      unify (IdType _) e = liftT $ Left $ ParseError (extrPos e)
 200 //                      "Expression cannot be an polymorf type."
 201     unify VarType e = typeExpr e
 202     //we have to cheat to decorate the error, can be done nicer?
 203         unify t=:(IdType id) e = typeExpr e >>= \tex->unify t tex
 204                 >>= \type->putIdent id type >>| pure type
 205     unify t e = StateT $ \s0 -> let res = runStateT m s0 in case res of
 206         Left err = Left $ decErr e err
 207         Right t = Right t //note, t :: (Type, Gamma)
 208     where m = typeExpr e >>= \tex-> unify t tex
 209
 210 instance unify Type where
 211         unify IntType IntType = pure IntType
 212         unify BoolType BoolType = pure BoolType
 213         unify CharType CharType = pure CharType
 214     unify (IdType i) t=:(IdType j) = replace i t >>| pure t
 215     unify t (IdType i) = unify (IdType i) t
 216     unify (IdType i) t = replace i t >>| pure t
 217     unify (ListType t1) (ListType t2) = unify t1 t2 >>| (pure $ ListType t1)
 218     unify (ta1 ->> ta2) (tb1 ->> tb2) = unify ta1 tb1 >>= \ta-> unify ta2 tb2
 219         >>= \tb-> pure (ta ->> tb)
 220     unify VoidType VoidType = pure VoidType
 221     unify VoidType t = pure t
 222     unify t VoidType = pure t
 223         unify t1 t2 = liftT $ Left $ UnifyError zero t1 t2
 224
 225 instance zero Pos where
 226         zero = {line=0,col=0}
 227
 228 decErr :: Expr SemError -> SemError
 229 decErr e (UnifyError _ t1 t2) = UnifyError (extrPos e) t1 t2
 230 decErr e (FieldSelectorError _ t fs) = FieldSelectorError (extrPos e) t fs
 231 decErr e (ParseError _ s) = ParseError (extrPos e) s
 232 decErr e err = err
 233
 234 dc2 :: Expr (Either SemError a) -> Either SemError a
 235 dc2 e (Right t) = Right t
 236 dc2 e (Left err) = Left err
 237
 238 extrPos :: Expr -> Pos
 239 extrPos (VarExpr p _) = p
 240 extrPos (Op2Expr p _ _ _) = p
 241 extrPos (Op1Expr p _ _) = p
 242 extrPos (IntExpr p _) = p
 243 extrPos (CharExpr p _) = p
 244 extrPos (BoolExpr p _) = p
 245 extrPos (FunExpr p _) = p
 246 extrPos (EmptyListExpr p) = p
 247 extrPos (TupleExpr p _) = p
 248
 249 instance toString Gamma where
 250         toString (mp, _) = concat
 251                 [concat [k, ": ", toString v, "\n"]\\(k, v) <- 'Map'.toList mp]
 252
 253 getRandomStream :: Int -> [String]
 254 getRandomStream i = genIdents $ filter (isAlpha o toChar) (genRandInt i)
 255     where
 256         genIdents r = let (ic, r2) = splitAt 5 r in [toString ic: genIdents r2]
 257
 258 freshIdent :: Env String
 259 freshIdent = get >>= \(st, [ident:rest])-> put (st, rest)
 260     >>| case 'Map'.get ident st of
 261         Nothing = pure ident
 262         _       = freshIdent
 263
 264 putIdent :: String Type -> Env Void
 265 putIdent i t = gets (\(st, r)->'Map'.get i st) >>= \mt -> case mt of
 266     Nothing = modify (\(st, r)->('Map'.put i t st, r))
 267     Just t2 = unify t t2 >>= \t3-> modify (\(st, r)->('Map'.put i t3 st, r))
 268
 269 replace :: String Type -> Env Void
 270 replace ident type = get >>= \(st, fr)->put ('Map'.fromList $
 271         map (itupdate ident type) ('Map'.toList st), fr)
 272     where
 273         itupdate :: String Type (String, Type) -> (String, Type)
 274         itupdate ident newtype ov=:(key, IdType type) = if (ident == type)
 275             (key, newtype) ov
 276         itupdate ident newtype (key, TupleType (t1, t2))
 277         # (_, t1) = itupdate ident newtype (key, t1)
 278         # (_, t2) = itupdate ident newtype (key, t2)
 279         = (key, TupleType (t1, t2))
 280         itupdate ident newtype (key, ListType t1)
 281         # (_, t1) = itupdate ident newtype (key, t1)
 282         = (key, ListType t1)
 283         itupdate _ _ k = k
 284
 285 instance toString SemError where
 286     toString (ParseError p e) = concat [toString p,
 287                 "SemError: ParseError: ", e]
 288     toString (UnifyError p t1 t2) = concat [ toString p,
 289         "SemError: Cannot unify types. Expected: ",
 290         toString t1, ". Given: ", toString t2]
 291     toString (FieldSelectorError p t fs) = concat [ toString p,
 292         "SemError: Cannot select ", toString fs, " from type: ",
 293         toString t]
 294     toString (OperatorError p o t) = concat [
 295         toString p,
 296         "SemError: No ", toString o, " for type ",
 297         toString t]
 298     toString (UndeclaredVariableError p ident) = concat [
 299         toString p, "SemError: identifier: ", ident, " undefined."]
 300     toString (ArgumentMisMatchError p s) = concat [toString p,
 301                 "SemError: Argument mismatch: ", s]
 302     toString (Error e) = "SemError: " +++ e
 303
 304 saveGamma :: Env Gamma
 305 saveGamma = get
 306
 307 restoreGamma :: Gamma -> Env Void
 308 restoreGamma (oldstate, _) = gets snd >>= \newr->put (oldstate, newr)
 309
 310 derive gEq Type
 311 instance == Type where
 312         (==) (IdType _) (IdType _) = True
 313         (==) o1 o2 = gEq{|*|} o1 o2