either binds ftw

[cc1516.git] / sem.icl

diff --git a/sem.icl b/sem.icl
index 2003038..667b6eb 100644 (file)
--- a/sem.icl
+++ b/sem.icl
@@ -1,6 +1,114 @@
 implementation module sem
 
+import qualified Data.Map as Map
+from Data.Func import $
+import Data.Maybe
+import Data.Either
+import Data.Functor
+import Control.Applicative
+import Control.Monad
+import Control.Monad.State
+import Control.Monad.Identity
 import StdMisc
+from StdFunc import id, const
+import StdString
+import StdList
 
-semanticAnalysis :: AST -> Either Error AST
-semanticAnalysis a = 
+from Text import class Text(concat), instance Text String
+
+import AST
+from parse import :: ParserOutput, :: Error
+
+:: Gamma :== 'Map'.Map String Type
+:: Env a :== (State Gamma (Either SemError a))
+
+get = state $ \s -> (s,s)
+
+putIdent :: String Type -> Env Void
+putIdent i t = gets ('Map'.get i) >>= \mt -> case mt of
+    Nothing = pure <$> modify ('Map'.put i t)
+    Just t2 = unify t t2 >>= \r -> case r of
+        Left e  = pure $ Left e
+        Right t3 = pure <$> modify ('Map'.put i t3)
+
+instance toString SemError where
+       toString (ParseError p e) = concat [
+               toString p,"SemError: ParseError: ", e]
+       toString (Error e) = "SemError: " +++ e
+       toString (UnifyError p t1 t2) = concat [
+               toString p,
+               "SemError: Cannot unify types. Expected: ",
+               toString t1, ". Given: ", toString t2]
+
+sem :: AST -> SemOutput
+sem (AST vd fd)
+# (eithervds, gamma) = runState (mapM semVarDecl vd) 'Map'.newMap
+# (eitherfds, gamma) = runState (mapM semFunDecl fd) gamma
+= case splitEithers eithervds of
+       (Left errs) = Left $ errs ++ [x\\(Left x)<-eitherfds]
+       (Right vds) = case splitEithers eitherfds of
+               (Left errs) = Left errs
+               (Right fds) = Right $ AST vds fds
+
+splitEithers :: [Either a b] -> Either [a] [b]
+splitEithers [] = Right []
+splitEithers [Right x:xs] = splitEithers xs >>= \rest->Right [x:rest]
+splitEithers xs = Left $ [x\\(Left x)<-xs]
+
+semFunDecl :: FunDecl -> Env FunDecl
+semFunDecl f = pure $ Right f
+
+semVarDecl :: VarDecl -> Env VarDecl
+semVarDecl v = pure $ Right v
+//Right v
+//semVarDecl vd=:(VarDecl pos type ident expr) = case unify type expr of //    Left e = Left e
+//     //TODO ident in de environment
+//     Right e = Right $ pure vd
+
+typeOp1 :: Pos Expr Type -> Env Type
+typeOp1 p expr rtype = typeExpr expr >>= \exprtype->case exprtype of
+       Left e = pure $ Left e
+       Right rtype = pure $ Right rtype
+       Right (IdType ident) = putIdent ident rtype >>| pure (Right rtype)
+       Right t = pure $ Left $ UnifyError p rtype t
+
+typeExpr :: Expr -> Env Type
+typeExpr (IntExpr _ _) = pure $ Right IntType
+typeExpr (CharExpr _ _) = pure $ Right CharType
+typeExpr (BoolExpr _ _) = pure $ Right BoolType
+typeExpr (Op1Expr p UnNegation expr) = typeOp1 p expr BoolType
+typeExpr (Op1Expr p UnMinus expr) = typeOp1 p expr IntType
+typeExpr (TupleExpr p (e1, e2)) = typeExpr e1 
+       >>= \ete1->typeExpr e2 >>= \ete2->pure (
+               ete1 >>= \te1->ete2 >>= \te2->Right $ TupleType (te1, te2))
+//typeExpr (Op1Expr p UnMinus expr) = typeExpr expr 
+//     >>= \exprtype->case exprtype of
+//             IntType = pure $ Right IntType
+//             t = Left $ UnifyError p IntType exprtype
+//typeExpr (Op2Expr Pos Expr Op2 Expr) = undef
+//typeExpr (FunExpr Pos FunCall) = undef
+//typeExpr (EmptyListExpr Pos) = undef
+//typeExpr (VarExpr Pos VarDef) = undef
+
+class unify a :: Type a -> Env Type
+
+instance unify Type where
+       unify IntType IntType = pure $ Right IntType
+       unify BoolType BoolType = pure $ Right BoolType
+       unify CharType CharType = pure $ Right CharType
+       unify _ _ = undef
+//
+//instance unify Expr where
+//     unify type expr = case type of
+//             _ ->> _ = Left $ ParseError (extrPos expr)
+//                     "Expression cannot be a higher order function. Yet..."
+//             VoidType = Left $ ParseError (extrPos expr)
+//                     "Expression cannot be a Void type."
+//             IdType _ = Left $ ParseError (extrPos expr)
+//                     "Expression cannot be an polymorf type."
+//             TupleType (_, _) = undef
+//             ListType _ = undef
+//             IntType = undef
+//             BoolType = undef
+//             CharType = undef
+//             VarType = undef