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))
+
+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
+//
+//typeExpr :: Expr -> Env Type
+//typeExpr (IntExpr _ _) = Right $ pure IntType
+//typeExpr (CharExpr _ _) = Right $ pure CharType
+//typeExpr (BoolExpr _ _) = Right $ pure BoolType
+//typeExpr (Op1Expr p UnNegation expr) = undef//typeExpr expr
+//// >>= \exprtype->case exprtype of
+//// Right BoolType = Right $ pure BoolType
+//// t = Left $ UnifyError p BoolType exprtype
+//typeExpr (Op1Expr p UnMinus expr) = undef// typeExpr expr
+//// >>= \exprtype->case exprtype of
+//// IntType = Right $ pure IntType
+//// t = Left $ UnifyError p IntType exprtype
+//// typeExpr (Op2Expr Pos Expr Op2 Expr) = undef
+////typeExpr (FunExpr Pos FunCall
+////typeExpr (EmptyListExpr Pos
+////typeExpr (TupleExpr Pos (Expr, Expr)
+////typeExpr (VarExpr Pos VarDef) = undef
+////
+//class unify a :: Type a -> Env a
+//
+//instance unify Type where
+// unify IntType IntType = Right $ pure IntType
+// unify BoolType BoolType = Right $ pure BoolType
+// unify CharType CharType = Right $ pure 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
+//
+//extrPos :: Expr -> Pos
+//extrPos (VarExpr p _) = p
+//extrPos (Op2Expr p _ _ _) = p
+//extrPos (Op1Expr p _ _) = p
+//extrPos (IntExpr p _) = p
+//extrPos (CharExpr p _) = p
+//extrPos (BoolExpr p _) = p
+//extrPos (FunExpr p _) = p
+//extrPos (EmptyListExpr p) = p
+//extrPos (TupleExpr p _) = p