Test/TestParser.hs

@@ -50,23 +50,23 @@ testClassWithMethodAndField = TestCase $
     assertEqual "expect class with method and field" [Class "WithMethodAndField" [MethodDeclaration "void" "foo" [] (Block []), MethodDeclaration "int" "bar" [] (Block [])] [VariableDeclaration "int" "value" Nothing]] $
     parse [CLASS,IDENTIFIER "WithMethodAndField",LBRACKET,VOID,IDENTIFIER "foo",LBRACE,RBRACE,LBRACKET,RBRACKET,INT,IDENTIFIER "value",SEMICOLON,INT,IDENTIFIER "bar",LBRACE,RBRACE,SEMICOLON,RBRACKET]
 testClassWithConstructor = TestCase $
-    assertEqual "expect class with constructor" [Class "WithConstructor" [MethodDeclaration "WithConstructor" "<init>" [] (Block [])] []] $
+    assertEqual "expect class with constructor" [Class "WithConstructor" [MethodDeclaration "void" "<init>" [] (Block [])] []] $
     parse [CLASS,IDENTIFIER "WithConstructor",LBRACKET,IDENTIFIER "WithConstructor",LBRACE,RBRACE,LBRACKET,RBRACKET,RBRACKET]
 
 
-testEmptyBlock = TestCase $ assertEqual "expect empty block" (Block []) $ parseBlock [LBRACKET,RBRACKET]
+testEmptyBlock = TestCase $ assertEqual "expect empty block" [Block []] $ parseStatement [LBRACKET,RBRACKET]
 testBlockWithLocalVarDecl = TestCase $
-    assertEqual "expect block with local var delcaration" (Block [LocalVariableDeclaration $ VariableDeclaration "int" "localvar" Nothing]) $
+    assertEqual "expect block with local var delcaration" [Block [LocalVariableDeclaration $ VariableDeclaration "int" "localvar" Nothing]] $
-    parseBlock [LBRACKET,INT,IDENTIFIER "localvar",SEMICOLON,RBRACKET]
+    parseStatement [LBRACKET,INT,IDENTIFIER "localvar",SEMICOLON,RBRACKET]
 testBlockWithMultipleLocalVarDecls = TestCase $
-    assertEqual "expect block with multiple local var declarations" (Block [LocalVariableDeclaration $ VariableDeclaration "int" "var1" Nothing, LocalVariableDeclaration $ VariableDeclaration "boolean" "var2" Nothing]) $
+    assertEqual "expect block with multiple local var declarations" [Block [LocalVariableDeclaration $ VariableDeclaration "int" "var1" Nothing, LocalVariableDeclaration $ VariableDeclaration "boolean" "var2" Nothing]] $
-    parseBlock [LBRACKET,INT,IDENTIFIER "var1",SEMICOLON,BOOLEAN,IDENTIFIER "var2",SEMICOLON,RBRACKET]
+    parseStatement [LBRACKET,INT,IDENTIFIER "var1",SEMICOLON,BOOLEAN,IDENTIFIER "var2",SEMICOLON,RBRACKET]
 testNestedBlocks = TestCase $
-    assertEqual "expect block with block inside" (Block [Block []]) $
+    assertEqual "expect block with block inside" [Block [Block []]] $
-    parseBlock [LBRACKET,LBRACKET,RBRACKET,RBRACKET]
+    parseStatement [LBRACKET,LBRACKET,RBRACKET,RBRACKET]
 testBlockWithEmptyStatement = TestCase $
-    assertEqual "expect empty block" (Block []) $
+    assertEqual "expect empty block" [Block []] $
-    parseBlock [LBRACKET,SEMICOLON,SEMICOLON,RBRACKET]
+    parseStatement [LBRACKET,SEMICOLON,SEMICOLON,RBRACKET]
 
 testExpressionIntLiteral = TestCase $
     assertEqual "expect IntLiteral" (IntegerLiteral 3) $
@@ -75,14 +75,14 @@ testFieldWithInitialization = TestCase $
     assertEqual "expect Class with initialized field" [Class "WithInitField" [] [VariableDeclaration "int" "number" $ Just $ IntegerLiteral 3]] $
     parse [CLASS,IDENTIFIER "WithInitField",LBRACKET,INT,IDENTIFIER "number",ASSIGN,INTEGERLITERAL 3,SEMICOLON,RBRACKET]
 testLocalBoolWithInitialization = TestCase $
-    assertEqual "expect block with with initialized local var" (Block [LocalVariableDeclaration $ VariableDeclaration "boolean" "b" $ Just $ BooleanLiteral False]) $
+    assertEqual "expect block with with initialized local var" [Block [LocalVariableDeclaration $ VariableDeclaration "boolean" "b" $ Just $ BooleanLiteral False]] $
-    parseBlock [LBRACKET,BOOLEAN,IDENTIFIER "b",ASSIGN,BOOLLITERAL False,SEMICOLON,RBRACKET]
+    parseStatement [LBRACKET,BOOLEAN,IDENTIFIER "b",ASSIGN,BOOLLITERAL False,SEMICOLON,RBRACKET]
 testFieldNullWithInitialization = TestCase $
     assertEqual "expect Class with initialized field" [Class "WithInitField" [] [VariableDeclaration "Object" "bar" $ Just NullLiteral]] $
     parse [CLASS,IDENTIFIER "WithInitField",LBRACKET,IDENTIFIER "Object",IDENTIFIER "bar",ASSIGN,NULLLITERAL,SEMICOLON,RBRACKET]
 testReturnVoid = TestCase $
-    assertEqual "expect block with return nothing" (Block [Return Nothing]) $
+    assertEqual "expect block with return nothing" [Block [Return Nothing]] $
-    parseBlock [LBRACKET,RETURN,SEMICOLON,RBRACKET]
+    parseStatement [LBRACKET,RETURN,SEMICOLON,RBRACKET]
 
 testExpressionNot = TestCase $
     assertEqual "expect expression not" (UnaryOperation Not (Reference "boar")) $
@@ -132,6 +132,18 @@ testExpressionXor = TestCase $
 testExpressionOr = TestCase $
     assertEqual "expect or expression" (BinaryOperation Or (Reference "bar") (Reference "baz")) $
     parseExpression [IDENTIFIER "bar",OR,IDENTIFIER "baz"]
+testExpressionPostIncrement = TestCase $
+    assertEqual "expect PostIncrement" (UnaryOperation PostIncrement (Reference "a")) $
+    parseExpression [IDENTIFIER "a",INCREMENT]
+testExpressionPostDecrement = TestCase $
+    assertEqual "expect PostDecrement" (UnaryOperation PostDecrement (Reference "a")) $
+    parseExpression [IDENTIFIER "a",DECREMENT]
+testExpressionPreIncrement = TestCase $
+    assertEqual "expect PreIncrement" (UnaryOperation PreIncrement (Reference "a")) $
+    parseExpression [INCREMENT,IDENTIFIER "a"]
+testExpressionPreDecrement = TestCase $
+    assertEqual "expect PreIncrement" (UnaryOperation PreDecrement (Reference "a")) $
+    parseExpression [DECREMENT,IDENTIFIER "a"]
 
 
 tests = TestList [
@@ -169,5 +181,9 @@ tests = TestList [
     testExpressionNotEqual,
     testExpressionAnd,
     testExpressionXor,
-    testExpressionOr
+    testExpressionOr,
+    testExpressionPostIncrement,
+    testExpressionPostDecrement,
+    testExpressionPreIncrement,
+    testExpressionPreDecrement
     ]

src/Ast.hs

@@ -20,7 +20,7 @@ data Statement
   deriving (Show, Eq)
 
 data StatementExpression
-  = Assignment Identifier Expression
+  = Assignment Expression Expression
   | ConstructorCall DataType [Expression]
   | MethodCall Expression Identifier [Expression]
   | TypedStatementExpression DataType StatementExpression
@@ -49,6 +49,10 @@ data BinaryOperator
 data UnaryOperator
   = Not
   | Minus
+  | PostIncrement
+  | PostDecrement
+  | PreIncrement
+  | PreDecrement
   deriving (Show, Eq)
 
 data Expression

src/Example.hs

@@ -49,7 +49,7 @@ exampleExpression :: Expression
 exampleExpression = BinaryOperation NameResolution (Reference "bob") (Reference "age")
 
 exampleAssignment :: Expression
-exampleAssignment = StatementExpressionExpression (Assignment "a" (IntegerLiteral 30))
+exampleAssignment = StatementExpressionExpression (Assignment (Reference "a") (IntegerLiteral 30))
 
 exampleMethodCall :: Statement
 exampleMethodCall = StatementExpressionStatement (MethodCall (Reference "this") "setAge" [IntegerLiteral 30])
@@ -58,7 +58,7 @@ exampleConstructorCall :: Statement
 exampleConstructorCall = LocalVariableDeclaration (VariableDeclaration "Person" "bob" (Just (StatementExpressionExpression  (ConstructorCall "Person" [IntegerLiteral 30]))))
 
 exampleNameResolution :: Expression
-exampleNameResolution = BinaryOperation NameResolution (Reference "b") (Reference "age")
+exampleNameResolution = BinaryOperation NameResolution (Reference "bob2") (Reference "age")
 
 exampleBlockResolution :: Statement
 exampleBlockResolution = Block [
@@ -80,7 +80,7 @@ exampleMethodCallAndAssignment = Block [
     LocalVariableDeclaration (VariableDeclaration "int" "age" (Just (StatementExpressionExpression (MethodCall (Reference "bob") "getAge" [])))),
     StatementExpressionStatement (MethodCall (Reference "bob") "setAge" [IntegerLiteral 30]),
     LocalVariableDeclaration (VariableDeclaration "int" "a" Nothing),
-    StatementExpressionStatement (Assignment "a" (Reference "age"))
+    StatementExpressionStatement (Assignment (Reference "a") (Reference "age"))
     ]
 
 
@@ -89,9 +89,18 @@ exampleMethodCallAndAssignmentFail = Block [
     LocalVariableDeclaration (VariableDeclaration "Person" "bob" (Just (StatementExpressionExpression  (ConstructorCall "Person" [IntegerLiteral 30])))),
     LocalVariableDeclaration (VariableDeclaration "int" "age" (Just (StatementExpressionExpression (MethodCall (Reference "bob") "getAge" [])))),
     StatementExpressionStatement (MethodCall (Reference "bob") "setAge" [IntegerLiteral 30]),
-    StatementExpressionStatement (Assignment "a" (Reference "age"))
+    StatementExpressionStatement (Assignment (Reference "a") (Reference "age"))
     ]
 
+exampleNameResolutionAssignment :: Statement
+exampleNameResolutionAssignment = Block [
+    LocalVariableDeclaration (VariableDeclaration "Person" "bob" (Just (StatementExpressionExpression  (ConstructorCall "Person" [IntegerLiteral 30])))),
+    StatementExpressionStatement (Assignment (BinaryOperation NameResolution (Reference "bob") (Reference "age")) (IntegerLiteral 30))
+    ]
+
+exampleCharIntOperation :: Expression
+exampleCharIntOperation = BinaryOperation Addition (CharacterLiteral 'a') (IntegerLiteral 1)
+
 testClasses :: [Class]
 testClasses = [
     Class "Person" [
@@ -113,10 +122,12 @@ testClasses = [
         (Block [
             LocalVariableDeclaration (VariableDeclaration "Person" "bob" (Just (StatementExpressionExpression (ConstructorCall "Person" [IntegerLiteral 25])))),
             StatementExpressionStatement (MethodCall (Reference "bob") "setAge" [IntegerLiteral 30]),
-            LocalVariableDeclaration (VariableDeclaration "int" "bobAge" (Just (StatementExpressionExpression (MethodCall (Reference "bob") "getAge" [])))),
+            LocalVariableDeclaration (VariableDeclaration "int" "bobAge" (Just (StatementExpressionExpression (MethodCall (Reference "bob2") "getAge" [])))),
             Return (Just (Reference "bobAge"))
         ])
-    ] []
+    ] [
+        VariableDeclaration "Person" "bob2" Nothing
+    ]
  ]
 
 runTypeCheck :: IO ()
@@ -151,7 +162,7 @@ runTypeCheck = do
 
     catch (do
         print "====================================================================================="
-        evaluatedNameResolution <- evaluate (typeCheckExpression exampleNameResolution [("b", "Person")] sampleClasses)
+        evaluatedNameResolution <- evaluate (typeCheckExpression exampleNameResolution [("this", "Main")] testClasses)
         printSuccess "Type checking of name resolution completed successfully"
         printResult "Result Name Resolution:" evaluatedNameResolution
       ) handleError
@@ -189,7 +200,7 @@ runTypeCheck = do
         let mainClass = fromJust $ find (\(Class className _ _) -> className == "Main") testClasses
         case mainClass of
             Class _ [mainMethod] _ -> do
-                let result = typeCheckMethodDeclaration mainMethod [] testClasses
+                let result = typeCheckMethodDeclaration mainMethod [("this", "Main")] testClasses
                 printSuccess "Full program type checking completed successfully."
                 printResult "Main method result:" result
       ) handleError
@@ -201,3 +212,17 @@ runTypeCheck = do
         printResult "Typed Program:" typedProgram
         ) handleError
     
+    catch (do
+        print "====================================================================================="
+        typedAssignment <- evaluate (typeCheckStatement exampleNameResolutionAssignment [] sampleClasses)
+        printSuccess "Type checking of name resolution assignment completed successfully"
+        printResult "Result Name Resolution Assignment:" typedAssignment
+        ) handleError
+
+    catch (do
+        print "====================================================================================="
+        evaluatedCharIntOperation <- evaluate (typeCheckExpression exampleCharIntOperation [] sampleClasses)
+        printSuccess "Type checking of char int operation completed successfully"
+        printResult "Result Char Int Operation:" evaluatedCharIntOperation
+        ) handleError
+

src/Parser/JavaParser.y

@@ -1,11 +1,11 @@
 {
-module Parser.JavaParser (parse, parseBlock, parseExpression) where
+module Parser.JavaParser (parse, parseStatement, parseExpression) where
 import Ast
 import Parser.Lexer
 }
 
 %name parse
-%name parseBlock block
+%name parseStatement statement
 %name parseExpression expression
 %tokentype { Token }
 %error { parseError }
@@ -127,8 +127,8 @@ classorinterfacetype : name { $1 }
 classmemberdeclaration : fielddeclaration { $1 }
                  | methoddeclaration { $1 }
 
-constructordeclaration : constructordeclarator constructorbody { case $1 of (classname, parameters) -> MethodDecl $ MethodDeclaration classname "<init>" parameters $2 }
+constructordeclaration : constructordeclarator constructorbody { case $1 of (classname, parameters) -> MethodDecl $ MethodDeclaration "void" "<init>" parameters $2 }
-                 |  modifiers constructordeclarator constructorbody { case $2 of (classname, parameters) -> MethodDecl $ MethodDeclaration classname "<init>" parameters $3 }
+                 |  modifiers constructordeclarator constructorbody { case $2 of (classname, parameters) -> MethodDecl $ MethodDeclaration "void" "<init>" parameters $3 }
 
 fielddeclaration : type variabledeclarators  SEMICOLON { FieldDecls $ map (convertDeclarator $1) $2 }
                  | modifiers type variabledeclarators  SEMICOLON { FieldDecls $ map (convertDeclarator $2) $3 }
@@ -275,13 +275,13 @@ assignmentoperator : ASSIGN{ }
                 --  | XOREQUAL { }
                 --  | OREQUAL{ }
 
-preincrementexpression : INCREMENT unaryexpression { }
+preincrementexpression : INCREMENT unaryexpression { UnaryOperation PreIncrement $2 }
 
-predecrementexpression : DECREMENT unaryexpression { }
+predecrementexpression : DECREMENT unaryexpression { UnaryOperation PreDecrement $2 }
 
-postincrementexpression : postfixexpression INCREMENT { }
+postincrementexpression : postfixexpression INCREMENT { UnaryOperation PostIncrement $1 }
 
-postdecrementexpression : postfixexpression DECREMENT { }
+postdecrementexpression : postfixexpression DECREMENT { UnaryOperation PostDecrement $1 }
 
 methodinvocation : name LBRACE   RBRACE  { }
                  | name LBRACE argumentlist RBRACE { }
@@ -296,15 +296,15 @@ conditionalandexpression : inclusiveorexpression { $1 }
 fieldaccess      : primary  DOT IDENTIFIER { }
 
 unaryexpression         : unaryexpressionnotplusminus { $1 }
-                --  | predecrementexpression { }
+                 | predecrementexpression { $1 }
                  | PLUS unaryexpression { $2 }
                  | MINUS unaryexpression { UnaryOperation Minus $2 }
-                --  | preincrementexpression { $1 }
+                 | preincrementexpression { $1 }
 
 postfixexpression : primary { $1 }
                  | name { Reference $1 }
-                --  | postincrementexpression { }
+                 | postincrementexpression { $1 }
-                --  | postdecrementexpression{ }
+                 | postdecrementexpression{ $1 }
 
 primary                 : primarynonewarray { $1 }
 

src/Typecheck.hs

@@ -10,9 +10,9 @@ typeCheckClass :: Class -> [Class] -> Class
 typeCheckClass (Class className methods fields) classes =
     let
         -- Create a symbol table from class fields and method entries
-        classFields = [(id, dt) | VariableDeclaration dt id _ <- fields]
+        -- TODO: Maybe remove method entries from the symbol table?
         methodEntries = [(methodName, className) | MethodDeclaration _ methodName _ _ <- methods]
-        initalSymTab = ("this", className) : classFields ++ methodEntries
+        initalSymTab = ("this", className) : methodEntries
         checkedMethods = map (\method -> typeCheckMethodDeclaration method initalSymTab classes) methods
     in Class className checkedMethods fields
 
@@ -37,118 +37,46 @@ typeCheckExpression (CharacterLiteral c) _ _ = TypedExpression "char" (Character
 typeCheckExpression (BooleanLiteral b) _ _ = TypedExpression "boolean" (BooleanLiteral b)
 typeCheckExpression NullLiteral _ _ = TypedExpression "null" NullLiteral
 typeCheckExpression (Reference id) symtab classes =
-  let type' = lookupType id symtab
+  case lookup id symtab of
-   in TypedExpression type' (Reference id)
+    Just t -> TypedExpression t (LocalVariable id)
+    Nothing ->
+      case lookup "this" symtab of
+        Just className ->
+          let classDetails = find (\(Class name _ _) -> name == className) classes
+          in case classDetails of
+            Just (Class _ _ fields) ->
+              let fieldTypes = [dt | VariableDeclaration dt fieldId _ <- fields, fieldId == id]
+              in case fieldTypes of
+                [fieldType] -> TypedExpression fieldType (FieldVariable id)
+                [] -> error $ "Field '" ++ id ++ "' not found in class '" ++ className ++ "'"
+                _ -> error $ "Ambiguous reference to field '" ++ id ++ "' in class '" ++ className ++ "'"
+            Nothing -> error $ "Class '" ++ className ++ "' not found for 'this'"
+        Nothing -> error $ "Context for 'this' not found in symbol table, unable to resolve '" ++ id ++ "'"
+
 typeCheckExpression (BinaryOperation op expr1 expr2) symtab classes =
   let expr1' = typeCheckExpression expr1 symtab classes
       expr2' = typeCheckExpression expr2 symtab classes
       type1 = getTypeFromExpr expr1'
       type2 = getTypeFromExpr expr2'
+      resultType = resolveResultType type1 type2
    in case op of
-        Addition ->
+        Addition -> checkArithmeticOperation op expr1' expr2' type1 type2 resultType
-          if type1 == "int" && type2 == "int"
+        Subtraction -> checkArithmeticOperation op expr1' expr2' type1 type2 resultType
-            then
+        Multiplication -> checkArithmeticOperation op expr1' expr2' type1 type2 resultType
-              TypedExpression "int" (BinaryOperation op expr1' expr2')
+        Division -> checkArithmeticOperation op expr1' expr2' type1 type2 resultType
-            else
+        Modulo -> checkArithmeticOperation op expr1' expr2' type1 type2 resultType
-              error "Addition operation requires two operands of type int"
+        BitwiseAnd -> checkBitwiseOperation op expr1' expr2' type1 type2
-        Subtraction ->
+        BitwiseOr -> checkBitwiseOperation op expr1' expr2' type1 type2
-          if type1 == "int" && type2 == "int"
+        BitwiseXor -> checkBitwiseOperation op expr1' expr2' type1 type2
-            then
+        CompareLessThan -> checkComparisonOperation op expr1' expr2' type1 type2
-              TypedExpression "int" (BinaryOperation op expr1' expr2')
+        CompareLessOrEqual -> checkComparisonOperation op expr1' expr2' type1 type2
-            else
+        CompareGreaterThan -> checkComparisonOperation op expr1' expr2' type1 type2
-              error "Subtraction operation requires two operands of type int"
+        CompareGreaterOrEqual -> checkComparisonOperation op expr1' expr2' type1 type2
-        Multiplication ->
+        CompareEqual -> checkEqualityOperation op expr1' expr2' type1 type2
-          if type1 == "int" && type2 == "int"
+        CompareNotEqual -> checkEqualityOperation op expr1' expr2' type1 type2
-            then
+        And -> checkLogicalOperation op expr1' expr2' type1 type2
-              TypedExpression "int" (BinaryOperation op expr1' expr2')
+        Or -> checkLogicalOperation op expr1' expr2' type1 type2
-            else
+        NameResolution -> resolveNameResolution expr1' expr2 symtab classes
-              error "Multiplication operation requires two operands of type int"
-        Division ->
-          if type1 == "int" && type2 == "int"
-            then
-              TypedExpression "int" (BinaryOperation op expr1' expr2')
-            else
-              error "Division operation requires two operands of type int"
-        BitwiseAnd ->
-          if type1 == "int" && type2 == "int"
-            then
-              TypedExpression "int" (BinaryOperation op expr1' expr2')
-            else
-              error "Bitwise AND operation requires two operands of type int"
-        BitwiseOr ->
-          if type1 == "int" && type2 == "int"
-            then
-              TypedExpression "int" (BinaryOperation op expr1' expr2')
-            else
-              error "Bitwise OR operation requires two operands of type int"
-        BitwiseXor ->
-          if type1 == "int" && type2 == "int"
-            then
-              TypedExpression "int" (BinaryOperation op expr1' expr2')
-            else
-              error "Bitwise XOR operation requires two operands of type int"
-        CompareLessThan ->
-          if type1 == "int" && type2 == "int"
-            then
-              TypedExpression "boolean" (BinaryOperation op expr1' expr2')
-            else
-              error "Less than operation requires two operands of type int"
-        CompareLessOrEqual ->
-          if type1 == "int" && type2 == "int"
-            then
-              TypedExpression "boolean" (BinaryOperation op expr1' expr2')
-            else
-              error "Less than or equal operation requires two operands of type int"
-        CompareGreaterThan ->
-          if type1 == "int" && type2 == "int"
-            then
-              TypedExpression "boolean" (BinaryOperation op expr1' expr2')
-            else
-              error "Greater than operation requires two operands of type int"
-        CompareGreaterOrEqual ->
-          if type1 == "int" && type2 == "int"
-            then
-              TypedExpression "boolean" (BinaryOperation op expr1' expr2')
-            else
-              error "Greater than or equal operation requires two operands of type int"
-        CompareEqual ->
-          if type1 == type2
-            then
-              TypedExpression "boolean" (BinaryOperation op expr1' expr2')
-            else
-              error "Equality operation requires two operands of the same type"
-        CompareNotEqual ->
-          if type1 == type2
-            then
-              TypedExpression "boolean" (BinaryOperation op expr1' expr2')
-            else
-              error "Inequality operation requires two operands of the same type"
-        And ->
-          if type1 == "boolean" && type2 == "boolean"
-            then
-              TypedExpression "boolean" (BinaryOperation op expr1' expr2')
-            else
-              error "Logical AND operation requires two operands of type boolean"
-        Or ->
-          if type1 == "boolean" && type2 == "boolean"
-            then
-              TypedExpression "boolean" (BinaryOperation op expr1' expr2')
-            else
-              error "Logical OR operation requires two operands of type boolean"
-        NameResolution ->
-          case (expr1', expr2) of
-              (TypedExpression t1 (Reference obj), Reference member) ->
-                  let objectType = lookupType obj symtab
-                      classDetails = find (\(Class className _ _) -> className == objectType) classes
-                  in case classDetails of
-                      Just (Class _ _ fields) ->
-                          let fieldTypes = [dt | VariableDeclaration dt id _ <- fields, id == member]
-                          in case fieldTypes of
-                              [resolvedType] -> TypedExpression resolvedType (BinaryOperation NameResolution expr1' (TypedExpression resolvedType expr2))
-                              [] -> error $ "Field '" ++ member ++ "' not found in class '" ++ objectType ++ "'"
-                              _ -> error $ "Ambiguous reference to field '" ++ member ++ "' in class '" ++ objectType ++ "'"
-                      Nothing -> error $ "Object '" ++ obj ++ "' does not correspond to a known class"
-              _ -> error "Name resolution requires object reference and field name"
 
 typeCheckExpression (UnaryOperation op expr) symtab classes =
   let expr' = typeCheckExpression expr symtab classes
@@ -164,8 +92,47 @@ typeCheckExpression (UnaryOperation op expr) symtab classes =
           if type' == "int"
             then
               TypedExpression "int" (UnaryOperation op expr')
+          else if type' == "char"
+            then
+              TypedExpression "char" (UnaryOperation op expr')
             else
-              error "Unary minus operation requires an operand of type int"
+              error "Unary minus operation requires an operand of type int or char"
+        PostIncrement ->
+          if type' == "int"
+            then
+              TypedExpression "int" (UnaryOperation op expr')
+          else if type' == "char"
+            then
+              TypedExpression "char" (UnaryOperation op expr')
+            else
+              error "Post-increment operation requires an operand of type int or char"
+        PostDecrement ->
+          if type' == "int"
+            then
+              TypedExpression "int" (UnaryOperation op expr')
+          else if type' == "char"
+            then
+              TypedExpression "char" (UnaryOperation op expr')
+            else
+              error "Post-decrement operation requires an operand of type int or char"
+        PreIncrement ->
+          if type' == "int"
+            then
+              TypedExpression "int" (UnaryOperation op expr')
+          else if type' == "char"
+            then
+              TypedExpression "char" (UnaryOperation op expr')
+            else
+              error "Pre-increment operation requires an operand of type int or char"
+        PreDecrement ->
+          if type' == "int"
+            then
+              TypedExpression "int" (UnaryOperation op expr')
+          else if type' == "char"
+            then
+              TypedExpression "char" (UnaryOperation op expr')
+            else
+              error "Pre-decrement operation requires an operand of type int or char"
 
 typeCheckExpression (StatementExpressionExpression stmtExpr) symtab classes =
   let stmtExpr' = typeCheckStatementExpression stmtExpr symtab classes
@@ -174,15 +141,16 @@ typeCheckExpression (StatementExpressionExpression stmtExpr) symtab classes =
 -- ********************************** Type Checking: StatementExpressions **********************************
 
 typeCheckStatementExpression :: StatementExpression -> [(Identifier, DataType)] -> [Class] -> StatementExpression
-typeCheckStatementExpression (Assignment id expr) symtab classes =
+typeCheckStatementExpression (Assignment ref expr) symtab classes =
   let expr' = typeCheckExpression expr symtab classes
+      ref' = typeCheckExpression ref symtab classes
       type' = getTypeFromExpr expr'
-      type'' = lookupType id symtab
+      type'' = getTypeFromExpr ref'
-   in if type' == type''
+    in
-        then
+      if type'' == type' then
-          TypedStatementExpression type' (Assignment id expr')
+        TypedStatementExpression type' (Assignment ref' expr')
-        else
+      else
-          error "Assignment type mismatch"
+        error $ "Type mismatch in assignment to variable: expected " ++ type'' ++ ", found " ++ type'
 
 typeCheckStatementExpression (ConstructorCall className args) symtab classes =
   case find (\(Class name _ _) -> name == className) classes of
@@ -327,8 +295,55 @@ unifyReturnTypes dt1 dt2
     | dt1 == dt2 = dt1
     | otherwise  = "Object"
 
-lookupType :: Identifier -> [(Identifier, DataType)] -> DataType
+resolveResultType :: DataType -> DataType -> DataType
-lookupType id symtab =
+resolveResultType "char" "char" = "char"
-  case lookup id symtab of
+resolveResultType "int" "int" = "int"
-    Just t  -> t
+resolveResultType "char" "int" = "int"
-    Nothing -> error ("Identifier " ++ id ++ " not found in symbol table")
+resolveResultType "int" "char" = "int"
+resolveResultType t1 t2
+  | t1 == t2 = t1
+  | otherwise = error $ "Incompatible types: " ++ t1 ++ " and " ++ t2
+
+checkArithmeticOperation :: BinaryOperator -> Expression -> Expression -> DataType -> DataType -> DataType -> Expression
+checkArithmeticOperation op expr1' expr2' type1 type2 resultType
+  | (type1 == "int" || type1 == "char") && (type2 == "int" || type2 == "char") =
+      TypedExpression resultType (BinaryOperation op expr1' expr2')
+  | otherwise = error $ "Arithmetic operation " ++ show op ++ " requires operands of type int or char"
+
+checkBitwiseOperation :: BinaryOperator -> Expression -> Expression -> DataType -> DataType -> Expression
+checkBitwiseOperation op expr1' expr2' type1 type2
+  | type1 == "int" && type2 == "int" =
+      TypedExpression "int" (BinaryOperation op expr1' expr2')
+  | otherwise = error $ "Bitwise operation " ++ show op ++ " requires operands of type int"
+
+checkComparisonOperation :: BinaryOperator -> Expression -> Expression -> DataType -> DataType -> Expression
+checkComparisonOperation op expr1' expr2' type1 type2
+  | (type1 == "int" || type1 == "char") && (type2 == "int" || type2 == "char") =
+      TypedExpression "boolean" (BinaryOperation op expr1' expr2')
+  | otherwise = error $ "Comparison operation " ++ show op ++ " requires operands of type int or char"
+
+checkEqualityOperation :: BinaryOperator -> Expression -> Expression -> DataType -> DataType -> Expression
+checkEqualityOperation op expr1' expr2' type1 type2
+  | type1 == type2 =
+      TypedExpression "boolean" (BinaryOperation op expr1' expr2')
+  | otherwise = error $ "Equality operation " ++ show op ++ " requires operands of the same type"
+
+checkLogicalOperation :: BinaryOperator -> Expression -> Expression -> DataType -> DataType -> Expression
+checkLogicalOperation op expr1' expr2' type1 type2
+  | type1 == "boolean" && type2 == "boolean" =
+      TypedExpression "boolean" (BinaryOperation op expr1' expr2')
+  | otherwise = error $ "Logical operation " ++ show op ++ " requires operands of type boolean"
+
+resolveNameResolution :: Expression -> Expression -> [(Identifier, DataType)] -> [Class] -> Expression
+resolveNameResolution expr1' (Reference ident2) symtab classes =
+  case getTypeFromExpr expr1' of
+    objType ->
+      case find (\(Class className _ _) -> className == objType) classes of
+        Just (Class _ _ fields) ->
+          let fieldTypes = [dt | VariableDeclaration dt id _ <- fields, id == ident2]
+          in case fieldTypes of
+            [resolvedType] -> TypedExpression resolvedType (BinaryOperation NameResolution expr1' (TypedExpression resolvedType (FieldVariable ident2)))
+            [] -> error $ "Field '" ++ ident2 ++ "' not found in class '" ++ objType ++ "'"
+            _ -> error $ "Ambiguous reference to field '" ++ ident2 ++ "' in class '" ++ objType ++ "'"
+        Nothing -> error $ "Class '" ++ objType ++ "' not found"
+resolveNameResolution _ _ _ _ = error "Name resolution requires object reference and field name"