From a363f872ee96379d8b0b9b14cb6faec9d74e7e92 Mon Sep 17 00:00:00 2001
From: Mart Lubbers <mart@martlubbers.net>
Date: Fri, 8 Apr 2016 20:03:33 +0200
Subject: [PATCH] added some type checking stuff. vardecl now works for
 basictypes and unary operators

---
 examples/example.spl | 11 ++++++--
 sem.dcl              |  1 +
 sem.icl              | 66 ++++++++++++++++++++++++++------------------
 spl.icl              |  3 +-
 4 files changed, 49 insertions(+), 32 deletions(-)

diff --git a/examples/example.spl b/examples/example.spl
index 4a55e35..e71c216 100644
--- a/examples/example.spl
+++ b/examples/example.spl
@@ -2,9 +2,14 @@
 	Three ways to implement the f acto rial function in SPL.
 	First the recursive version .
 */
-var r = 1;
-var facN = 1;
-var ok = True;
+Int r = 1;
+Char r = 1;
+Int r = -1;
+Void r = 0;
+Bool r = !True;
+Bool r = -True;
+//var facN = 1;
+//var ok = True;
 
 facR(n) :: Int -> Int {
 	if (n < 2) {
diff --git a/sem.dcl b/sem.dcl
index 6351c04..b34bbc3 100644
--- a/sem.dcl
+++ b/sem.dcl
@@ -7,6 +7,7 @@ from StdOverloaded import class toString
 :: SemError 
 	= ParseError Pos String 
 	| UnifyError Pos Type Type 
+	| UnifyErrorStub Type Type 
 	| Error String
 :: SemOutput :== Either [SemError] AST
 
diff --git a/sem.icl b/sem.icl
index 667b6eb..7132135 100644
--- a/sem.icl
+++ b/sem.icl
@@ -35,6 +35,7 @@ instance toString SemError where
 	toString (ParseError p e) = concat [
 		toString p,"SemError: ParseError: ", e]
 	toString (Error e) = "SemError: " +++ e
+	toString (UnifyErrorStub t1 t2) = toString (UnifyError {line=0,col=0} t1 t2)
 	toString (UnifyError p t1 t2) = concat [
 		toString p,
 		"SemError: Cannot unify types. Expected: ",
@@ -59,18 +60,15 @@ semFunDecl :: FunDecl -> Env FunDecl
 semFunDecl f = pure $ Right f
 
 semVarDecl :: VarDecl -> Env VarDecl
-semVarDecl v = pure $ Right v
+semVarDecl vd=:(VarDecl pos type ident ex) = unify type ex
+	>>= \et->pure (
+		et >>= \t->pure $ VarDecl pos t ident ex)
 //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
+typeOp1 p expr rtype = unify rtype expr
 
 typeExpr :: Expr -> Env Type
 typeExpr (IntExpr _ _) = pure $ Right IntType
@@ -81,10 +79,6 @@ 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
@@ -92,23 +86,41 @@ typeExpr (TupleExpr p (e1, e2)) = typeExpr e1
 
 class unify a :: Type a -> Env Type
 
+instance unify Expr where
+	unify (_ ->> _) e = pure $ Left $ ParseError (extrPos e)
+			"Expression cannot be a higher order function. Yet..."
+	unify VoidType e = pure $ Left $ ParseError (extrPos e)
+			"Expression cannot be a Void type."
+	unify (IdType _) e = pure $ Left $ ParseError (extrPos e)
+			"Expression cannot be an polymorf type."
+	unify t e = typeExpr e
+		>>= \eithertype->case eithertype of
+			Left e = pure $ Left e
+			Right tex = unify t tex >>= \eitherun->case eitherun of
+				Left err = pure $ Left $ decErr e err
+				Right t = pure $ Right t
+
 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
+	unify t1 t2 = pure $ Left $ UnifyError zero t1 t2
+
+instance zero Pos where
+	zero = {line=0,col=0}
+
+decErr :: Expr SemError -> SemError
+decErr e (UnifyError _ t1 t2) = UnifyError (extrPos e) t1 t2
+decErr e (ParseError _ s) = ParseError (extrPos e) s
+decErr e err = err
+
+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
diff --git a/spl.icl b/spl.icl
index 240de63..1690d71 100644
--- a/spl.icl
+++ b/spl.icl
@@ -66,8 +66,7 @@ Start w
 			# stdin = if (not args.parse) stdin (
 				stdin <<<  "//PARSER\n" <<< toString parseOut <<< "//PARSER\n")
 			= case sem parseOut of
-				(Left e) = snd $ fclose (stdin <<< "SEMERRORS: " <<<
-					join "\n" (map toString e)) w
+				(Left e) = snd $ fclose (stdin <<< join "\n" (map toString e)) w
 				(Right semOut)
 				# stdin = if (not args.sem) stdin (
 					stdin <<<  "//SEM\n" <<< toString semOut <<< "//SEM\n")
-- 
2.20.1