Merge pull request 'Add initial typechecker for AST' (#2) from typedAST into master

Reviewed-on: #2

Test/TestByteCodeGenerator.hs

@@ -107,10 +107,12 @@ testBasicConstantPool = TestCase $ assertEqual "basic constant pool" expectedCla
 testFields = TestCase $ assertEqual "fields in constant pool" expectedClassWithFields $ classBuilder classWithFields emptyClassFile
 testMethodDescriptor = TestCase $ assertEqual "method descriptor" "(II)I" (methodDescriptor method)
 testMethodAssembly = TestCase $ assertEqual "method assembly" expectedClassWithMethod (classBuilder classWithMethod emptyClassFile)
+testFindMethodIndex = TestCase $ assertEqual "find method" (Just 0) (findMethodIndex expectedClassWithMethod "add_two_numbers")
 
 tests = TestList [
     TestLabel "Basic constant pool" testBasicConstantPool,
     TestLabel "Fields constant pool" testFields,
     TestLabel "Method descriptor building" testMethodDescriptor,
-    TestLabel "Method assembly" testMethodAssembly
+    TestLabel "Method assembly" testMethodAssembly,
+    TestLabel "Find method by name" testFindMethodIndex
     ]

Test/TestParser.hs

@@ -18,11 +18,286 @@ testBooleanField = TestCase $
 testIntField = TestCase $ 
     assertEqual "expect class with int field" [Class "WithInt" [] [VariableDeclaration "int" "value" Nothing]] $
     parse [CLASS,IDENTIFIER "WithInt",LBRACKET,INT,IDENTIFIER "value",SEMICOLON,RBRACKET]
+testCustomTypeField = TestCase $
+    assertEqual "expect class with foo field" [Class "WithFoo" [] [VariableDeclaration "Foo" "value" Nothing]] $
+    parse [CLASS,IDENTIFIER "WithFoo",LBRACKET,IDENTIFIER "Foo",IDENTIFIER "value",SEMICOLON,RBRACKET]
+testMultipleDeclarationSameLine = TestCase $
+    assertEqual "expect class with two int fields" [Class "TwoInts" [] [VariableDeclaration "int" "num1" Nothing, VariableDeclaration "int" "num2" Nothing]] $
+    parse [CLASS,IDENTIFIER "TwoInts",LBRACKET,INT,IDENTIFIER "num1",COMMA,IDENTIFIER "num2",SEMICOLON,RBRACKET]
+testMultipleDeclarations = TestCase $
+    assertEqual "expect class with int and char field" [Class "Multiple" [] [VariableDeclaration "int" "value" Nothing, VariableDeclaration "char" "letter" Nothing]] $
+    parse [CLASS,IDENTIFIER "Multiple",LBRACKET,INT,IDENTIFIER "value",SEMICOLON,CHAR,IDENTIFIER "letter",SEMICOLON,RBRACKET]
+testWithModifier = TestCase $
+    assertEqual "expect class with int field" [Class "WithInt" [] [VariableDeclaration "int" "value" Nothing]] $
+    parse [ABSTRACT,CLASS,IDENTIFIER "WithInt",LBRACKET,PUBLIC,INT,IDENTIFIER "value",SEMICOLON,RBRACKET]
+
+testEmptyMethod = TestCase $
+    assertEqual "expect class with method" [Class "WithMethod" [MethodDeclaration "int" "foo" [] (Block [])] []] $
+    parse [CLASS,IDENTIFIER "WithMethod",LBRACKET,INT,IDENTIFIER "foo",LBRACE,RBRACE,SEMICOLON,RBRACKET]
+testEmptyPrivateMethod = TestCase $ 
+    assertEqual "expect class with method" [Class "WithMethod" [MethodDeclaration "int" "foo" [] (Block [])] []] $
+    parse [CLASS,IDENTIFIER "WithMethod",LBRACKET,PRIVATE,INT,IDENTIFIER "foo",LBRACE,RBRACE,LBRACKET,RBRACKET,RBRACKET]
+testEmptyVoidMethod = TestCase $
+    assertEqual "expect class with method" [Class "WithMethod" [MethodDeclaration "void" "foo" [] (Block [])] []] $
+    parse [CLASS,IDENTIFIER "WithMethod",LBRACKET,VOID,IDENTIFIER "foo",LBRACE,RBRACE,LBRACKET,RBRACKET,RBRACKET]
+testEmptyMethodWithParam = TestCase $
+    assertEqual "expect class with method with param" [Class "WithParam" [MethodDeclaration "void" "foo" [ParameterDeclaration "int" "param"] (Block [])] []] $
+    parse [CLASS,IDENTIFIER "WithParam",LBRACKET,VOID,IDENTIFIER "foo",LBRACE,INT,IDENTIFIER "param",RBRACE,SEMICOLON,RBRACKET]
+testEmptyMethodWithParams = TestCase $
+    assertEqual "expect class with multiple params" [Class "WithParams" [MethodDeclaration "void" "foo" [ParameterDeclaration "int" "p1",ParameterDeclaration "Custom" "p2"] (Block [])] []] $
+    parse [CLASS,IDENTIFIER "WithParams",LBRACKET,VOID,IDENTIFIER "foo",LBRACE,INT,IDENTIFIER "p1",COMMA,IDENTIFIER "Custom",IDENTIFIER "p2",RBRACE,SEMICOLON,RBRACKET]
+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 "void" "<init>" [] (Block [])] []] $
+    parse [CLASS,IDENTIFIER "WithConstructor",LBRACKET,IDENTIFIER "WithConstructor",LBRACE,RBRACE,LBRACKET,RBRACKET,RBRACKET]
+testConstructorWithParams = TestCase $
+    assertEqual "expect constructor with params" [Class "WithParams" [MethodDeclaration "void" "<init>" [ParameterDeclaration "int" "p1"] (Block [])] []] $
+    parse [CLASS,IDENTIFIER "WithParams",LBRACKET,IDENTIFIER "WithParams",LBRACE,INT,IDENTIFIER "p1",RBRACE,LBRACKET,RBRACKET,RBRACKET]
+testConstructorWithStatements = TestCase $
+    assertEqual "expect constructor with statement" [Class "WithConstructor" [MethodDeclaration "void" "<init>" [] (Block [Return Nothing])] []] $
+    parse [CLASS,IDENTIFIER "WithConstructor",LBRACKET,IDENTIFIER "WithConstructor",LBRACE,RBRACE,LBRACKET,RETURN,SEMICOLON,RBRACKET,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]] $
+    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]] $
+    parseStatement [LBRACKET,INT,IDENTIFIER "var1",SEMICOLON,BOOLEAN,IDENTIFIER "var2",SEMICOLON,RBRACKET]
+testNestedBlocks = TestCase $
+    assertEqual "expect block with block inside" [Block [Block []]] $
+    parseStatement [LBRACKET,LBRACKET,RBRACKET,RBRACKET]
+testBlockWithEmptyStatement = TestCase $
+    assertEqual "expect empty block" [Block []] $
+    parseStatement [LBRACKET,SEMICOLON,SEMICOLON,RBRACKET]
+
+testExpressionIntLiteral = TestCase $
+    assertEqual "expect IntLiteral" (IntegerLiteral 3) $
+    parseExpression [INTEGERLITERAL 3]
+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]] $
+    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]] $
+    parseStatement [LBRACKET,RETURN,SEMICOLON,RBRACKET]
+
+testExpressionNot = TestCase $
+    assertEqual "expect expression not" (UnaryOperation Not (Reference "boar")) $
+    parseExpression [NOT,IDENTIFIER "boar"]
+testExpressionMinus = TestCase $
+    assertEqual "expect expression minus" (UnaryOperation Minus (Reference "boo")) $
+    parseExpression [MINUS,IDENTIFIER "boo"]
+testExpressionMultiplication = TestCase $
+    assertEqual "expect multiplication" (BinaryOperation Multiplication (Reference "bar") (IntegerLiteral 3)) $
+    parseExpression [IDENTIFIER "bar",TIMES,INTEGERLITERAL 3]
+testExpressionDivision = TestCase $
+    assertEqual "expect division" (BinaryOperation Division (Reference "bar") (IntegerLiteral 3)) $
+    parseExpression [IDENTIFIER "bar",DIV,INTEGERLITERAL 3]
+testExpressionModulo = TestCase $
+    assertEqual "expect modulo operation" (BinaryOperation Modulo (Reference "bar") (IntegerLiteral 3)) $
+    parseExpression [IDENTIFIER "bar",MODULO,INTEGERLITERAL 3]
+testExpressionAddition = TestCase $
+    assertEqual "expect addition" (BinaryOperation Addition (Reference "bar") (IntegerLiteral 3)) $
+    parseExpression [IDENTIFIER "bar",PLUS,INTEGERLITERAL 3]
+testExpressionSubtraction = TestCase $
+    assertEqual "expect subtraction" (BinaryOperation Subtraction (Reference "bar") (IntegerLiteral 3)) $
+    parseExpression [IDENTIFIER "bar",MINUS,INTEGERLITERAL 3]
+testExpressionLessThan = TestCase $
+    assertEqual "expect comparision less than" (BinaryOperation CompareLessThan (Reference "bar") (IntegerLiteral 3)) $
+    parseExpression [IDENTIFIER "bar",LESS,INTEGERLITERAL 3]
+testExpressionGreaterThan = TestCase $
+    assertEqual "expect comparision greater than" (BinaryOperation CompareGreaterThan (Reference "bar") (IntegerLiteral 3)) $
+    parseExpression [IDENTIFIER "bar",GREATER,INTEGERLITERAL 3]
+testExpressionLessThanEqual = TestCase $
+    assertEqual "expect comparision less than or equal" (BinaryOperation CompareLessOrEqual (Reference "bar") (IntegerLiteral 3)) $
+    parseExpression [IDENTIFIER "bar",LESSEQUAL,INTEGERLITERAL 3]
+testExpressionGreaterThanOrEqual = TestCase $
+    assertEqual "expect comparision greater than or equal" (BinaryOperation CompareGreaterOrEqual (Reference "bar") (IntegerLiteral 3)) $
+    parseExpression [IDENTIFIER "bar",GREATEREQUAL,INTEGERLITERAL 3]
+testExpressionEqual = TestCase $
+    assertEqual "expect comparison equal" (BinaryOperation CompareEqual (Reference "bar") (IntegerLiteral 3)) $
+    parseExpression [IDENTIFIER "bar",EQUAL,INTEGERLITERAL 3]
+testExpressionNotEqual = TestCase $
+    assertEqual "expect comparison equal" (BinaryOperation CompareNotEqual (Reference "bar") (IntegerLiteral 3)) $
+    parseExpression [IDENTIFIER "bar",NOTEQUAL,INTEGERLITERAL 3]
+testExpressionAnd = TestCase $
+    assertEqual "expect and expression" (BinaryOperation And (Reference "bar") (Reference "baz")) $
+    parseExpression [IDENTIFIER "bar",AND,IDENTIFIER "baz"]
+testExpressionXor = TestCase $
+    assertEqual "expect xor expression" (BinaryOperation BitwiseXor (Reference "bar") (Reference "baz")) $
+    parseExpression [IDENTIFIER "bar",XOR,IDENTIFIER "baz"]
+testExpressionOr = TestCase $
+    assertEqual "expect or expression" (BinaryOperation Or (Reference "bar") (Reference "baz")) $
+    parseExpression [IDENTIFIER "bar",OR,IDENTIFIER "baz"]
+testExpressionPostIncrement = TestCase $
+    assertEqual "expect PostIncrement" (StatementExpressionExpression $ PostIncrement (Reference "a")) $
+    parseExpression [IDENTIFIER "a",INCREMENT]
+testExpressionPostDecrement = TestCase $
+    assertEqual "expect PostDecrement" (StatementExpressionExpression $ PostDecrement (Reference "a")) $
+    parseExpression [IDENTIFIER "a",DECREMENT]
+testExpressionPreIncrement = TestCase $
+    assertEqual "expect PreIncrement" (StatementExpressionExpression $ PreIncrement (Reference "a")) $
+    parseExpression [INCREMENT,IDENTIFIER "a"]
+testExpressionPreDecrement = TestCase $
+    assertEqual "expect PreIncrement" (StatementExpressionExpression $ PreDecrement (Reference "a")) $
+    parseExpression [DECREMENT,IDENTIFIER "a"]
+testExpressionAssign = TestCase $
+    assertEqual "expect assign 5 to a" (StatementExpressionExpression (Assignment (Reference "a") (IntegerLiteral 5))) $
+    parseExpression [IDENTIFIER "a",ASSIGN,INTEGERLITERAL 5]
+testExpressionTimesEqual = TestCase $
+    assertEqual "expect assign and multiplication" (StatementExpressionExpression (Assignment (Reference "a") (BinaryOperation Multiplication (Reference "a") (IntegerLiteral 5)))) $
+    parseExpression [IDENTIFIER "a",TIMESEQUAL,INTEGERLITERAL 5]
+testExpressionDivideEqual = TestCase $
+    assertEqual "expect assign and division" (StatementExpressionExpression (Assignment (Reference "a") (BinaryOperation Division (Reference "a") (IntegerLiteral 5)))) $
+    parseExpression [IDENTIFIER "a",DIVEQUAL,INTEGERLITERAL 5]
+testExpressionPlusEqual = TestCase $
+    assertEqual "expect assign and addition" (StatementExpressionExpression (Assignment (Reference "a") (BinaryOperation Addition (Reference "a") (IntegerLiteral 5)))) $
+    parseExpression [IDENTIFIER "a",PLUSEQUAL,INTEGERLITERAL 5]
+testExpressionMinusEqual = TestCase $
+    assertEqual "expect assign and subtraction" (StatementExpressionExpression (Assignment (Reference "a") (BinaryOperation Subtraction (Reference "a") (IntegerLiteral 5)))) $
+    parseExpression [IDENTIFIER "a",MINUSEQUAL,INTEGERLITERAL 5]
+testExpressionThis = TestCase $
+    assertEqual "expect this" (Reference "this") $
+    parseExpression [THIS]
+testExpressionBraced = TestCase $
+    assertEqual "expect braced expresssion" (BinaryOperation Multiplication (Reference "b") (BinaryOperation Addition (Reference "a") (IntegerLiteral 3))) $
+    parseExpression [IDENTIFIER "b",TIMES,LBRACE,IDENTIFIER "a",PLUS,INTEGERLITERAL 3,RBRACE]
+
+testExpressionPrecedence = TestCase $
+    assertEqual "expect times to be inner expression" (BinaryOperation Addition (BinaryOperation Multiplication (Reference "b") (Reference "a")) (IntegerLiteral 3)) $
+    parseExpression [IDENTIFIER "b",TIMES,IDENTIFIER "a",PLUS,INTEGERLITERAL 3]
+
+testExpressionMethodCallNoParams = TestCase $
+    assertEqual "expect methodcall no params" (StatementExpressionExpression (MethodCall (Reference "this") "foo" [])) $
+    parseExpression [IDENTIFIER "foo",LBRACE,RBRACE]
+testExpressionMethodCallOneParam = TestCase $
+    assertEqual "expect methodcall one param" (StatementExpressionExpression (MethodCall (Reference "this") "foo" [Reference "a"])) $
+    parseExpression [IDENTIFIER "foo",LBRACE,IDENTIFIER "a",RBRACE]
+testExpressionMethodCallTwoParams = TestCase $
+    assertEqual "expect methocall two params" (StatementExpressionExpression (MethodCall (Reference "this") "foo" [Reference "a", IntegerLiteral 5])) $
+    parseExpression [IDENTIFIER "foo",LBRACE,IDENTIFIER "a",COMMA,INTEGERLITERAL 5,RBRACE]
+testExpressionThisMethodCall = TestCase $
+    assertEqual "expect this methocall" (StatementExpressionExpression (MethodCall (Reference "this") "foo" [])) $
+    parseExpression [THIS,DOT,IDENTIFIER "foo",LBRACE,RBRACE]
+testExpressionThisMethodCallParam = TestCase $
+    assertEqual "expect this methocall" (StatementExpressionExpression (MethodCall (Reference "this") "foo" [Reference "x"])) $
+    parseExpression [THIS,DOT,IDENTIFIER "foo",LBRACE,IDENTIFIER "x",RBRACE]
+testExpressionFieldAccess = TestCase $
+    assertEqual "expect NameResolution" (BinaryOperation NameResolution (Reference "this") (Reference "b")) $
+    parseExpression [THIS,DOT,IDENTIFIER "b"]
+testExpressionSimpleFieldAccess = TestCase $
+    assertEqual "expect Reference" (Reference "a") $
+    parseExpression [IDENTIFIER "a"]
+testExpressionFieldSubAccess = TestCase $
+    assertEqual "expect NameResolution without this" (BinaryOperation NameResolution (Reference "a") (Reference "b")) $
+    parseExpression [IDENTIFIER "a",DOT,IDENTIFIER "b"]
+testExpressionConstructorCall = TestCase $
+    assertEqual "expect constructor call" (StatementExpressionExpression (ConstructorCall "Foo" [])) $
+    parseExpression [NEW,IDENTIFIER "Foo",LBRACE,RBRACE]
+
+testStatementIfThen = TestCase $
+    assertEqual "expect empty ifthen" [If (Reference "a") (Block [Block []]) Nothing] $
+    parseStatement [IF,LBRACE,IDENTIFIER "a",RBRACE,LBRACKET,RBRACKET]
+testStatementIfThenElse = TestCase $
+    assertEqual "expect empty ifthen" [If (Reference "a") (Block [Block []]) (Just (Block [Block []]))] $
+    parseStatement [IF,LBRACE,IDENTIFIER "a",RBRACE,LBRACKET,RBRACKET,ELSE,LBRACKET,RBRACKET]
+testStatementWhile = TestCase $
+    assertEqual "expect while" [While (Reference "a") (Block [Block []])] $
+    parseStatement [WHILE,LBRACE,IDENTIFIER "a",RBRACE,LBRACKET,RBRACKET]
+testStatementAssign = TestCase $
+    assertEqual "expect assign 5" [StatementExpressionStatement (Assignment (Reference "a") (IntegerLiteral 5))] $
+    parseStatement [IDENTIFIER "a",ASSIGN,INTEGERLITERAL 5,SEMICOLON]
+
+testStatementMethodCallNoParams = TestCase $
+    assertEqual "expect methodcall statement no params" [StatementExpressionStatement (MethodCall (Reference "this") "foo" [])] $
+    parseStatement [IDENTIFIER "foo",LBRACE,RBRACE,SEMICOLON]
+testStatementConstructorCall = TestCase $
+    assertEqual "expect constructor call" [StatementExpressionStatement (ConstructorCall "Foo" [])] $
+    parseStatement [NEW,IDENTIFIER "Foo",LBRACE,RBRACE,SEMICOLON]
+testStatementConstructorCallWithArgs = TestCase $
+    assertEqual "expect constructor call" [StatementExpressionStatement (ConstructorCall "Foo" [Reference "b"])] $
+    parseStatement [NEW,IDENTIFIER "Foo",LBRACE,IDENTIFIER "b",RBRACE,SEMICOLON]
+
+testStatementPreIncrement = TestCase $
+    assertEqual "expect increment" [StatementExpressionStatement $ PostIncrement $ Reference "a"] $
+    parseStatement [IDENTIFIER "a",INCREMENT,SEMICOLON]
 
 
 tests = TestList [
     testSingleEmptyClass,
     testTwoEmptyClasses,
     testBooleanField,
-    testIntField
+    testIntField,
+    testCustomTypeField,
+    testMultipleDeclarations,
+    testWithModifier,
+    testEmptyMethod,
+    testEmptyPrivateMethod,
+    testEmptyVoidMethod,
+    testEmptyMethodWithParam,
+    testEmptyMethodWithParams,
+    testClassWithMethodAndField,
+    testClassWithConstructor,
+    testConstructorWithParams,
+    testConstructorWithStatements,
+    testEmptyBlock,
+    testBlockWithLocalVarDecl,
+    testBlockWithMultipleLocalVarDecls,
+    testNestedBlocks,
+    testBlockWithEmptyStatement,
+    testExpressionIntLiteral,
+    testFieldWithInitialization,
+    testLocalBoolWithInitialization,
+    testFieldNullWithInitialization,
+    testReturnVoid,
+    testExpressionNot,
+    testExpressionMinus,
+    testExpressionLessThan,
+    testExpressionGreaterThan,
+    testExpressionLessThanEqual,
+    testExpressionGreaterThanOrEqual,
+    testExpressionEqual,
+    testExpressionNotEqual,
+    testExpressionAnd,
+    testExpressionXor,
+    testExpressionOr,
+    testExpressionPostIncrement,
+    testExpressionPostDecrement,
+    testExpressionPreIncrement,
+    testExpressionPreDecrement,
+    testExpressionAssign,
+    testExpressionTimesEqual,
+    testExpressionTimesEqual,
+    testExpressionDivideEqual,
+    testExpressionPlusEqual,
+    testExpressionMinusEqual,
+    testExpressionBraced,
+    testExpressionThis,
+    testExpressionPrecedence,
+    testExpressionMethodCallNoParams,
+    testExpressionMethodCallOneParam,
+    testExpressionMethodCallTwoParams,
+    testExpressionThisMethodCall,
+    testExpressionThisMethodCallParam,
+    testExpressionFieldAccess,
+    testExpressionSimpleFieldAccess,
+    testExpressionFieldSubAccess,
+    testExpressionConstructorCall,
+    testStatementIfThen,
+    testStatementIfThenElse,
+    testStatementWhile,
+    testStatementAssign,
+    testStatementMethodCallNoParams,
+    testStatementConstructorCall,
+    testStatementConstructorCallWithArgs,
+    testStatementPreIncrement
     ]

project.cabal

@@ -12,18 +12,21 @@ executable compiler
                         utf8-string,
                         bytestring
     default-language:   Haskell2010
-    hs-source-dirs:     src,
-                        src/ByteCode,
-                        src/ByteCode/ClassFile
+    hs-source-dirs:     src
     build-tool-depends: alex:alex, happy:happy
     other-modules:      Parser.Lexer,
-                        Parser.JavaParser
+                        Parser.JavaParser,
                         Ast,
                         Example,
                         Typecheck,
                         ByteCode.ByteUtil,
                         ByteCode.ClassFile,
-                        ByteCode.ClassFile.Generator,
+                        ByteCode.Generation.Generator,
+                        ByteCode.Generation.Assembler.ExpressionAndStatement,
+                        ByteCode.Generation.Assembler.Method,
+                        ByteCode.Generation.Builder.Class,
+                        ByteCode.Generation.Builder.Field,
+                        ByteCode.Generation.Builder.Method,
                         ByteCode.Constants
 
 test-suite tests

src/Ast.hs

@@ -20,10 +20,14 @@ data Statement
   deriving (Show, Eq)
 
 data StatementExpression
-  = Assignment Identifier Expression
+  = Assignment Expression Expression
   | ConstructorCall DataType [Expression]
   | MethodCall Expression Identifier [Expression]
   | TypedStatementExpression DataType StatementExpression
+  | PostIncrement Expression
+  | PostDecrement Expression
+  | PreIncrement Expression
+  | PreDecrement Expression
   deriving (Show, Eq)
 
 data BinaryOperator
@@ -31,6 +35,7 @@ data BinaryOperator
   | Subtraction
   | Multiplication
   | Division
+  | Modulo
   | BitwiseAnd
   | BitwiseOr
   | BitwiseXor

src/ByteCode/ClassFile.hs

@@ -5,7 +5,8 @@ module ByteCode.ClassFile(
     ClassFile(..),
     Operation(..),
     serialize,
-    emptyClassFile
+    emptyClassFile,
+    opcodeEncodingLength
 ) where
 
 import Data.Word
@@ -31,6 +32,7 @@ data Operation = Opiadd
                | Opior
                | Opixor
                | Opineg
+               | Opdup
                | Opif_icmplt Word16
                | Opif_icmple Word16
                | Opif_icmpgt Word16
@@ -41,6 +43,8 @@ data Operation = Opiadd
                | Opreturn
                | Opireturn
                | Opareturn
+               | Opinvokespecial Word16
+               | Opgoto Word16
                | Opsipush Word16
                | Opldc_w Word16
                | Opaload Word16
@@ -48,7 +52,7 @@ data Operation = Opiadd
                | Opastore Word16
                | Opistore Word16
                | Opputfield Word16
-               | OpgetField Word16
+               | Opgetfield Word16
     deriving (Show, Eq)
 
 
@@ -87,6 +91,37 @@ emptyClassFile = ClassFile {
         attributes = []
     }
 
+opcodeEncodingLength :: Operation -> Word16
+opcodeEncodingLength Opiadd                 = 1
+opcodeEncodingLength Opisub                 = 1
+opcodeEncodingLength Opimul                 = 1
+opcodeEncodingLength Opidiv                 = 1
+opcodeEncodingLength Opiand                 = 1
+opcodeEncodingLength Opior                  = 1
+opcodeEncodingLength Opixor                 = 1
+opcodeEncodingLength Opineg                 = 1
+opcodeEncodingLength Opdup                  = 1
+opcodeEncodingLength (Opif_icmplt _)        = 3
+opcodeEncodingLength (Opif_icmple _)        = 3
+opcodeEncodingLength (Opif_icmpgt _)        = 3
+opcodeEncodingLength (Opif_icmpge _)        = 3
+opcodeEncodingLength (Opif_icmpeq _)        = 3
+opcodeEncodingLength (Opif_icmpne _)        = 3
+opcodeEncodingLength Opaconst_null          = 1
+opcodeEncodingLength Opreturn               = 1
+opcodeEncodingLength Opireturn              = 1
+opcodeEncodingLength Opareturn              = 1
+opcodeEncodingLength (Opinvokespecial _)    = 3
+opcodeEncodingLength (Opgoto _)             = 3
+opcodeEncodingLength (Opsipush _)           = 3
+opcodeEncodingLength (Opldc_w _)            = 3
+opcodeEncodingLength (Opaload _)            = 4
+opcodeEncodingLength (Opiload _)            = 4
+opcodeEncodingLength (Opastore _)           = 4
+opcodeEncodingLength (Opistore _)           = 4
+opcodeEncodingLength (Opputfield _)         = 3
+opcodeEncodingLength (Opgetfield _)         = 3
+
 class Serializable a where
     serialize :: a -> [Word8]
 
@@ -116,6 +151,7 @@ instance Serializable Operation where
     serialize Opior                     = [0x80]
     serialize Opixor                    = [0x82]
     serialize Opineg                    = [0x74]
+    serialize Opdup                     = [0x59]
     serialize (Opif_icmplt branch)      = 0xA1 : unpackWord16 branch
     serialize (Opif_icmple branch)      = 0xA4 : unpackWord16 branch
     serialize (Opif_icmpgt branch)      = 0xA3 : unpackWord16 branch
@@ -126,6 +162,8 @@ instance Serializable Operation where
     serialize Opreturn                  = [0xB1]
     serialize Opireturn                 = [0xAC]
     serialize Opareturn                 = [0xB0]
+    serialize (Opinvokespecial index)   = 0xB7 : unpackWord16 index
+    serialize (Opgoto index)            = 0xA7 : unpackWord16 index
     serialize (Opsipush index)          = 0x11 : unpackWord16 index
     serialize (Opldc_w index)           = 0x13 : unpackWord16 index
     serialize (Opaload index)           = [0xC4, 0x19] ++ unpackWord16 index
@@ -133,7 +171,7 @@ instance Serializable Operation where
     serialize (Opastore index)          = [0xC4, 0x3A] ++ unpackWord16 index
     serialize (Opistore index)          = [0xC4, 0x36] ++ unpackWord16 index
     serialize (Opputfield index)        = 0xB5 : unpackWord16 index
-    serialize (OpgetField index)   = 0xB4 : unpackWord16 index
+    serialize (Opgetfield index)        = 0xB4 : unpackWord16 index
 
 instance Serializable Attribute where
     serialize (CodeAttribute { attributeMaxStack = maxStack,
@@ -151,7 +189,7 @@ instance Serializable Attribute where
             ++ unpackWord16 0                                               -- attributes_count
 
 instance Serializable ClassFile where
-    serialize classfile  = unpackWord32 0xC0FEBABE                                           -- magic
+    serialize classfile  = unpackWord32 0xCAFEBABE                                           -- magic
                         ++ unpackWord16 0                                                    -- minor version
                         ++ unpackWord16 49                                                   -- major version
                         ++ unpackWord16 (fromIntegral (1 + length (constantPool classfile))) -- constant pool count

src/ByteCode/ClassFile/Generator.hs

@@ -1,169 +0,0 @@
-module ByteCode.ClassFile.Generator(
-    classBuilder,
-    datatypeDescriptor,
-    methodParameterDescriptor,
-    methodDescriptor,
-) where
-
-import ByteCode.Constants
-import ByteCode.ClassFile (ClassFile (..), ConstantInfo (..), MemberInfo(..), Operation(..), Attribute(..))
-import Ast
-import Data.Char
-
-
-type ClassFileBuilder a = a -> ClassFile -> ClassFile
-
-
-datatypeDescriptor :: String -> String
-datatypeDescriptor "void" = "V"
-datatypeDescriptor "int" = "I"
-datatypeDescriptor "char" = "C"
-datatypeDescriptor "boolean" = "B"
-datatypeDescriptor x = "L" ++ x
-
-methodParameterDescriptor :: String -> String
-methodParameterDescriptor "void" = "V"
-methodParameterDescriptor "int" = "I"
-methodParameterDescriptor "char" = "C"
-methodParameterDescriptor "boolean" = "B"
-methodParameterDescriptor x = "L" ++ x ++ ";"
-
-methodDescriptor :: MethodDeclaration -> String
-methodDescriptor (MethodDeclaration returntype _ parameters _) = let 
-        parameter_types = [datatype | ParameterDeclaration datatype _ <- parameters]
-    in
-        "("
-        ++ (concat (map methodParameterDescriptor parameter_types))
-        ++ ")"
-        ++ datatypeDescriptor returntype
-
-classBuilder :: ClassFileBuilder Class
-classBuilder (Class name methods fields) _ = let
-        baseConstants = [
-            ClassInfo 4,
-            MethodRefInfo 1 3,
-            NameAndTypeInfo 5 6,
-            Utf8Info "java/lang/Object",
-            Utf8Info "<init>",
-            Utf8Info "()V",
-            Utf8Info "Code"
-            ]
-        nameConstants = [ClassInfo 9, Utf8Info name]
-        nakedClassFile = ClassFile {
-            constantPool = baseConstants ++ nameConstants,
-            accessFlags = accessPublic,
-            thisClass = 8,
-            superClass = 1,
-            fields = [],
-            methods = [],
-            attributes = []
-        }
-    in
-        foldr methodBuilder (foldr fieldBuilder nakedClassFile fields) methods
-        
-        
-
-fieldBuilder :: ClassFileBuilder VariableDeclaration
-fieldBuilder (VariableDeclaration datatype name _) input = let
-        baseIndex = 1 + length (constantPool input)
-        constants = [
-                FieldRefInfo (fromIntegral (thisClass input)) (fromIntegral (baseIndex + 1)),
-                NameAndTypeInfo (fromIntegral (baseIndex + 2)) (fromIntegral (baseIndex + 3)),
-                Utf8Info name,
-                Utf8Info (datatypeDescriptor datatype)
-            ]
-        field = MemberInfo {
-            memberAccessFlags = accessPublic,
-            memberNameIndex = (fromIntegral (baseIndex + 2)),
-            memberDescriptorIndex = (fromIntegral (baseIndex + 3)),
-            memberAttributes = []
-            }
-    in
-        input {
-            constantPool = (constantPool input) ++ constants,
-            fields = (fields input) ++ [field]
-        }
-
-methodBuilder :: ClassFileBuilder MethodDeclaration
-methodBuilder (MethodDeclaration returntype name parameters statement) input = let
-        baseIndex = 1 + length (constantPool input)
-        constants = [
-                FieldRefInfo (fromIntegral (thisClass input)) (fromIntegral (baseIndex + 1)),
-                NameAndTypeInfo (fromIntegral (baseIndex + 2)) (fromIntegral (baseIndex + 3)),
-                Utf8Info name,
-                Utf8Info (methodDescriptor (MethodDeclaration returntype name parameters (Block [])))
-            ]
-        --code = assembleByteCode statement
-        method = MemberInfo {
-            memberAccessFlags = accessPublic,
-            memberNameIndex = (fromIntegral (baseIndex + 2)),
-            memberDescriptorIndex = (fromIntegral (baseIndex + 3)),
-            memberAttributes = [
-                   CodeAttribute {
-                        attributeMaxStack = 420,
-                        attributeMaxLocals = 420,
-                        attributeCode = [Opiadd]
-                    }
-                ]
-            }
-    in
-        input {
-            constantPool = (constantPool input) ++ constants,
-            methods = (fields input) ++ [method]
-        }
-
-type Assembler a = a -> ([ConstantInfo], [Operation]) -> ([ConstantInfo], [Operation])
-
-returnOperation :: DataType -> Operation
-returnOperation dtype
-    | elem dtype ["int", "char", "boolean"] = Opireturn
-    | otherwise                             = Opareturn
-
-binaryOperation :: BinaryOperator -> Operation
-binaryOperation Addition        = Opiadd
-binaryOperation Subtraction     = Opisub
-binaryOperation Multiplication  = Opimul
-binaryOperation Division        = Opidiv
-binaryOperation BitwiseAnd      = Opiand
-binaryOperation BitwiseOr       = Opior
-binaryOperation BitwiseXor      = Opixor
-
-assembleMethod :: Assembler MethodDeclaration
-assembleMethod (MethodDeclaration _ _ _ (Block statements)) (constants, ops) =
-    foldr assembleStatement (constants, ops) statements
-
-assembleStatement :: Assembler Statement
-assembleStatement (TypedStatement stype (Return expr)) (constants, ops) = case expr of
-    Nothing -> (constants, ops ++ [Opreturn])
-    Just expr -> let
-            (expr_constants, expr_ops) = assembleExpression expr (constants, ops)
-        in  
-            (expr_constants, expr_ops ++ [returnOperation stype])
-
-assembleExpression :: Assembler Expression
-assembleExpression (TypedExpression _ (BinaryOperation op a b)) (constants, ops)
-    | elem op [Addition, Subtraction, Multiplication, Division, BitwiseAnd, BitwiseOr, BitwiseXor] = let
-            (aConstants, aOps) = assembleExpression a (constants, ops)
-            (bConstants, bOps) = assembleExpression b (aConstants, aOps)
-        in
-            (bConstants, bOps ++ [binaryOperation op])
-assembleExpression (TypedExpression _ (CharacterLiteral literal)) (constants, ops) = 
-    (constants, ops ++ [Opsipush (fromIntegral (ord literal))])
-assembleExpression (TypedExpression _ (BooleanLiteral literal)) (constants, ops) = 
-    (constants, ops ++ [Opsipush (if literal then 1 else 0)])
-assembleExpression (TypedExpression _ (IntegerLiteral literal)) (constants, ops)
-    | literal <= 32767 && literal >= -32768 = (constants, ops ++ [Opsipush (fromIntegral literal)])
-    | otherwise = (constants ++ [IntegerInfo (fromIntegral literal)], ops ++ [Opldc_w (fromIntegral (1 + length constants))])
-assembleExpression (TypedExpression _ NullLiteral) (constants, ops) = 
-    (constants, ops ++ [Opaconst_null])
-assembleExpression (TypedExpression etype (UnaryOperation Not expr)) (constants, ops) = let
-        (exprConstants, exprOps) = assembleExpression expr (constants, ops)
-        newConstant = fromIntegral (1 + length exprConstants)
-    in case etype of
-        "int" -> (exprConstants ++ [IntegerInfo 0x7FFFFFFF], exprOps ++ [Opldc_w newConstant, Opixor])
-        "char" -> (exprConstants, exprOps ++ [Opsipush 0xFFFF, Opixor])
-        "boolean" -> (exprConstants, exprOps ++ [Opsipush 0x01, Opixor])
-assembleExpression (TypedExpression _ (UnaryOperation Minus expr)) (constants, ops) = let
-        (exprConstants, exprOps) = assembleExpression expr (constants, ops)
-    in
-        (exprConstants, exprOps ++ [Opineg])

src/ByteCode/Generation/Assembler/ExpressionAndStatement.hs

@@ -0,0 +1,228 @@
+module ByteCode.Generation.Assembler.ExpressionAndStatement where
+
+import Ast
+import ByteCode.ClassFile(ClassFile (..), ConstantInfo (..), MemberInfo(..), Operation(..), Attribute(..), opcodeEncodingLength)
+import ByteCode.Generation.Generator
+import Data.List
+import Data.Char
+import ByteCode.Generation.Builder.Field
+
+assembleExpression :: Assembler Expression
+assembleExpression (constants, ops, lvars) (TypedExpression _ (BinaryOperation op a b))
+    | elem op [Addition, Subtraction, Multiplication, Division, BitwiseAnd, BitwiseOr, BitwiseXor] = let
+            (aConstants, aOps, _) = assembleExpression (constants, ops, lvars) a
+            (bConstants, bOps, _) = assembleExpression (aConstants, aOps, lvars) b
+        in
+            (bConstants, bOps ++ [binaryOperation op], lvars)
+    | elem op [CompareEqual, CompareNotEqual, CompareLessThan, CompareLessOrEqual, CompareGreaterThan, CompareGreaterOrEqual] = let
+            (aConstants, aOps, _) = assembleExpression (constants, ops, lvars) a
+            (bConstants, bOps, _) = assembleExpression (aConstants, aOps, lvars) b
+            cmp_op = comparisonOperation op 9
+            cmp_ops = [cmp_op, Opsipush 0, Opgoto 6, Opsipush 1]
+        in
+            (bConstants, bOps ++ cmp_ops, lvars)
+
+assembleExpression (constants, ops, lvars) (TypedExpression _ (CharacterLiteral literal)) =
+    (constants, ops ++ [Opsipush (fromIntegral (ord literal))], lvars)
+
+assembleExpression (constants, ops, lvars) (TypedExpression _ (BooleanLiteral literal)) =
+    (constants, ops ++ [Opsipush (if literal then 1 else 0)], lvars)
+
+assembleExpression (constants, ops, lvars) (TypedExpression _ (IntegerLiteral literal))
+    | literal <= 32767 && literal >= -32768 = (constants, ops ++ [Opsipush (fromIntegral literal)], lvars)
+    | otherwise = (constants ++ [IntegerInfo (fromIntegral literal)], ops ++ [Opldc_w (fromIntegral (1 + length constants))], lvars)
+
+assembleExpression (constants, ops, lvars) (TypedExpression _ NullLiteral) =
+    (constants, ops ++ [Opaconst_null], lvars)
+
+assembleExpression (constants, ops, lvars) (TypedExpression etype (UnaryOperation Not expr)) = let
+        (exprConstants, exprOps, _) = assembleExpression (constants, ops, lvars) expr
+        newConstant = fromIntegral (1 + length exprConstants)
+    in case etype of
+        "int" -> (exprConstants ++ [IntegerInfo 0x7FFFFFFF], exprOps ++ [Opldc_w newConstant, Opixor], lvars)
+        "char" -> (exprConstants, exprOps ++ [Opsipush 0xFFFF, Opixor], lvars)
+        "boolean" -> (exprConstants, exprOps ++ [Opsipush 0x01, Opixor], lvars)
+
+assembleExpression (constants, ops, lvars) (TypedExpression _ (UnaryOperation Minus expr)) = let
+        (exprConstants, exprOps, _) = assembleExpression (constants, ops, lvars) expr
+    in
+        (exprConstants, exprOps ++ [Opineg], lvars)
+
+assembleExpression (constants, ops, lvars) (TypedExpression _ (FieldVariable name)) = let
+        fieldIndex = findFieldIndex constants name
+    in case fieldIndex of
+        Just index -> (constants, ops ++ [Opaload 0, Opgetfield (fromIntegral index)], lvars)
+        Nothing -> error ("No such field found in constant pool: " ++ name)
+
+assembleExpression (constants, ops, lvars) (TypedExpression dtype (LocalVariable name)) = let
+        localIndex = findIndex ((==) name) lvars
+        isPrimitive = elem dtype ["char", "boolean", "int"]
+    in case localIndex of
+        Just index -> (constants, ops ++ if isPrimitive then [Opiload (fromIntegral index)] else [Opaload (fromIntegral index)], lvars)
+        Nothing -> error ("No such local variable found in local variable pool: " ++ name)
+
+assembleExpression (constants, ops, lvars) (TypedExpression dtype (StatementExpressionExpression stmtexp)) =
+        assembleStatementExpression (constants, ops, lvars) stmtexp
+
+assembleExpression _ expr = error ("unimplemented: " ++ show expr)
+
+
+
+
+-- TODO untested
+assembleStatementExpression :: Assembler StatementExpression
+assembleStatementExpression
+    (constants, ops, lvars)
+    (TypedStatementExpression _ (Assignment (TypedExpression dtype (LocalVariable name)) expr)) = let
+        localIndex = findIndex ((==) name) lvars
+        (constants_a, ops_a, _) = assembleExpression (constants, ops, lvars) expr
+        isPrimitive = elem dtype ["char", "boolean", "int"]
+    in case localIndex of
+        Just index -> (constants_a, ops_a ++ if isPrimitive then [Opistore (fromIntegral index)] else [Opastore (fromIntegral index)], lvars)
+        Nothing -> error ("No such local variable found in local variable pool: " ++ name)
+
+assembleStatementExpression
+    (constants, ops, lvars)
+    (TypedStatementExpression _ (Assignment (TypedExpression dtype (FieldVariable name)) expr)) = let
+        fieldIndex = findFieldIndex constants name
+        (constants_a, ops_a, _) = assembleExpression (constants, ops ++ [Opaload 0], lvars) expr
+    in case fieldIndex of
+        Just index -> (constants_a, ops_a ++ [Opputfield (fromIntegral index)], lvars)
+        Nothing -> error ("No such field variable found in constant pool: " ++ name)
+
+
+assembleStatementExpression
+    (constants, ops, lvars)
+    (TypedStatementExpression _ (PreIncrement (TypedExpression dtype (LocalVariable name)))) = let
+        localIndex = findIndex ((==) name) lvars
+        expr = (TypedExpression dtype (LocalVariable name))
+        (exprConstants, exprOps, _) = assembleExpression (constants, ops, lvars) expr
+        incrOps = exprOps ++ [Opsipush 1, Opiadd, Opdup]
+    in case localIndex of
+        Just index -> (exprConstants, incrOps ++ [Opistore (fromIntegral index)], lvars)
+        Nothing -> error("No such local variable found in local variable pool: " ++ name)
+
+assembleStatementExpression
+    (constants, ops, lvars)
+    (TypedStatementExpression _ (PostIncrement (TypedExpression dtype (LocalVariable name)))) = let
+        localIndex = findIndex ((==) name) lvars
+        expr = (TypedExpression dtype (LocalVariable name))
+        (exprConstants, exprOps, _) = assembleExpression (constants, ops, lvars) expr
+        incrOps = exprOps ++ [Opdup, Opsipush 1, Opiadd]
+    in case localIndex of
+        Just index -> (exprConstants, incrOps ++ [Opistore (fromIntegral index)], lvars)
+        Nothing -> error("No such local variable found in local variable pool: " ++ name)
+
+assembleStatementExpression
+    (constants, ops, lvars)
+    (TypedStatementExpression _ (PreDecrement (TypedExpression dtype (LocalVariable name)))) = let
+        localIndex = findIndex ((==) name) lvars
+        expr = (TypedExpression dtype (LocalVariable name))
+        (exprConstants, exprOps, _) = assembleExpression (constants, ops, lvars) expr
+        incrOps = exprOps ++ [Opsipush 1, Opiadd, Opisub]
+    in case localIndex of
+        Just index -> (exprConstants, incrOps ++ [Opistore (fromIntegral index)], lvars)
+        Nothing -> error("No such local variable found in local variable pool: " ++ name)
+
+assembleStatementExpression
+    (constants, ops, lvars)
+    (TypedStatementExpression _ (PostDecrement (TypedExpression dtype (LocalVariable name)))) = let
+        localIndex = findIndex ((==) name) lvars
+        expr = (TypedExpression dtype (LocalVariable name))
+        (exprConstants, exprOps, _) = assembleExpression (constants, ops, lvars) expr
+        incrOps = exprOps ++ [Opdup, Opsipush 1, Opisub]
+    in case localIndex of
+        Just index -> (exprConstants, incrOps ++ [Opistore (fromIntegral index)], lvars)
+        Nothing -> error("No such local variable found in local variable pool: " ++ name)
+
+assembleStatementExpression
+    (constants, ops, lvars)
+    (TypedStatementExpression _ (PreIncrement (TypedExpression dtype (FieldVariable name)))) = let
+        fieldIndex = findFieldIndex constants name
+        expr = (TypedExpression dtype (FieldVariable name))
+        (exprConstants, exprOps, _) = assembleExpression (constants, ops ++ [Opaload 0], lvars) expr
+        incrOps = exprOps ++ [Opsipush 1, Opiadd, Opdup]
+    in case fieldIndex of
+        Just index -> (exprConstants, incrOps ++ [Opputfield (fromIntegral index)], lvars)
+        Nothing -> error("No such field variable found in field variable pool: " ++ name)
+
+assembleStatementExpression
+    (constants, ops, lvars)
+    (TypedStatementExpression _ (PostIncrement (TypedExpression dtype (FieldVariable name)))) = let
+        fieldIndex = findFieldIndex constants name
+        expr = (TypedExpression dtype (FieldVariable name))
+        (exprConstants, exprOps, _) = assembleExpression (constants, ops ++ [Opaload 0], lvars) expr
+        incrOps = exprOps ++ [Opdup, Opsipush 1, Opiadd]
+    in case fieldIndex of
+        Just index -> (exprConstants, incrOps ++ [Opputfield (fromIntegral index)], lvars)
+        Nothing -> error("No such field variable found in field variable pool: " ++ name)
+
+assembleStatementExpression
+    (constants, ops, lvars)
+    (TypedStatementExpression _ (PreDecrement (TypedExpression dtype (FieldVariable name)))) = let
+        fieldIndex = findFieldIndex constants name
+        expr = (TypedExpression dtype (FieldVariable name))
+        (exprConstants, exprOps, _) = assembleExpression (constants, ops ++ [Opaload 0], lvars) expr
+        incrOps = exprOps ++ [Opsipush 1, Opiadd, Opisub]
+    in case fieldIndex of
+        Just index -> (exprConstants, incrOps ++ [Opputfield (fromIntegral index)], lvars)
+        Nothing -> error("No such field variable found in field variable pool: " ++ name)
+
+assembleStatementExpression
+    (constants, ops, lvars)
+    (TypedStatementExpression _ (PostDecrement (TypedExpression dtype (FieldVariable name)))) = let
+        fieldIndex = findFieldIndex constants name
+        expr = (TypedExpression dtype (FieldVariable name))
+        (exprConstants, exprOps, _) = assembleExpression (constants, ops ++ [Opaload 0], lvars) expr
+        incrOps = exprOps ++ [Opdup, Opsipush 1, Opisub]
+    in case fieldIndex of
+        Just index -> (exprConstants, incrOps ++ [Opputfield (fromIntegral index)], lvars)
+        Nothing -> error("No such field variable found in field variable pool: " ++ name)
+
+
+
+
+
+assembleStatement :: Assembler Statement
+assembleStatement (constants, ops, lvars) (TypedStatement stype (Return expr)) = case expr of
+    Nothing -> (constants, ops ++ [Opreturn], lvars)
+    Just expr -> let
+            (expr_constants, expr_ops, _) = assembleExpression (constants, ops, lvars) expr
+        in
+            (expr_constants, expr_ops ++ [returnOperation stype], lvars)
+assembleStatement (constants, ops, lvars) (TypedStatement _ (Block statements)) =
+    foldl assembleStatement (constants, ops, lvars) statements
+assembleStatement (constants, ops, lvars) (TypedStatement _ (If expr if_stmt else_stmt)) = let
+        (constants_cmp, ops_cmp, _) = assembleExpression (constants, [], lvars) expr
+        (constants_ifa, ops_ifa, _) = assembleStatement (constants_cmp, [], lvars) if_stmt
+        (constants_elsea, ops_elsea, _) = case else_stmt of
+            Nothing -> (constants_ifa, [], lvars)
+            Just stmt -> assembleStatement (constants_ifa, [], lvars) stmt
+        -- +6 because we insert 2 gotos, one for if, one for else
+        if_length = sum (map opcodeEncodingLength ops_ifa) + 6
+        -- +3 because we need to account for the goto in the if statement.
+        else_length = sum (map opcodeEncodingLength ops_elsea) + 3
+    in
+        (constants_ifa, ops ++ ops_cmp ++ [Opsipush 0, Opif_icmpeq if_length] ++ ops_ifa ++ [Opgoto else_length] ++ ops_elsea, lvars)
+assembleStatement (constants, ops, lvars) (TypedStatement _ (While expr stmt)) = let
+        (constants_cmp, ops_cmp, _) = assembleExpression (constants, [], lvars) expr
+        (constants_stmta, ops_stmta, _) = assembleStatement (constants_cmp, [], lvars) stmt
+        -- +3 because we insert 2 gotos, one for the comparison, one for the goto back to the comparison
+        stmt_length = sum (map opcodeEncodingLength ops_stmta) + 6
+        entire_length = stmt_length + sum (map opcodeEncodingLength ops_cmp)
+    in
+        (constants_stmta, ops ++ ops_cmp ++ [Opsipush 0, Opif_icmpeq stmt_length] ++ ops_stmta ++ [Opgoto (-entire_length)], lvars)
+assembleStatement (constants, ops, lvars) (TypedStatement _ (LocalVariableDeclaration (VariableDeclaration dtype name expr))) = let
+        isPrimitive = elem dtype ["char", "boolean", "int"]
+        (constants_init, ops_init, _) = case expr of
+            Just exp -> assembleExpression (constants, ops, lvars) exp
+            Nothing -> (constants, ops ++ if isPrimitive then [Opsipush 0] else [Opaconst_null], lvars)
+        localIndex = fromIntegral (length lvars)
+        storeLocal = if isPrimitive then [Opistore localIndex] else [Opastore localIndex]
+    in
+        (constants_init, ops_init ++ storeLocal, lvars ++ [name])
+
+assembleStatement (constants, ops, lvars) (TypedStatement _ (StatementExpressionStatement expr)) =
+    assembleStatementExpression (constants, ops, lvars) expr
+
+assembleStatement _ stmt = error ("Not yet implemented: " ++ show stmt)

src/ByteCode/Generation/Assembler/Method.hs

@@ -0,0 +1,20 @@
+module ByteCode.Generation.Assembler.Method where
+
+import Ast
+import ByteCode.ClassFile(ClassFile (..), ConstantInfo (..), MemberInfo(..), Operation(..), Attribute(..), opcodeEncodingLength)
+import ByteCode.Generation.Generator
+import ByteCode.Generation.Assembler.ExpressionAndStatement
+
+assembleMethod :: Assembler MethodDeclaration
+assembleMethod (constants, ops, lvars) (MethodDeclaration _ name _ (TypedStatement _ (Block statements)))
+    | name == "<init>" = let
+            (constants_a, ops_a, lvars_a) = foldl assembleStatement (constants, ops, lvars) statements
+            init_ops = [Opaload 0, Opinvokespecial 2]
+        in
+            (constants_a, init_ops ++ ops_a ++ [Opreturn], lvars_a)
+    | otherwise = let
+            (constants_a, ops_a, lvars_a) = foldl assembleStatement (constants, ops, lvars) statements
+            init_ops = [Opaload 0]
+        in
+            (constants_a, init_ops ++ ops_a, lvars_a)
+assembleMethod _ (MethodDeclaration _ _ _ stmt) = error ("Block expected for method body, got: " ++ show stmt) 

src/ByteCode/Generation/Builder/Class.hs

@@ -0,0 +1,44 @@
+module ByteCode.Generation.Builder.Class where
+
+import ByteCode.Generation.Builder.Field
+import ByteCode.Generation.Builder.Method
+import ByteCode.Generation.Generator
+import Ast
+import ByteCode.ClassFile(ClassFile (..), ConstantInfo (..), MemberInfo(..), Operation(..), Attribute(..), opcodeEncodingLength)
+import ByteCode.Constants
+
+injectDefaultConstructor :: [MethodDeclaration] -> [MethodDeclaration]
+injectDefaultConstructor pre
+    | any (\(MethodDeclaration _ name _ _) -> name == "<init>") pre = pre
+    | otherwise = pre ++ [MethodDeclaration "void" "<init>" [] (TypedStatement "void" (Block []))]
+
+
+classBuilder :: ClassFileBuilder Class
+classBuilder (Class name methods fields) _ = let
+        baseConstants = [
+            ClassInfo 4,
+            MethodRefInfo 1 3,
+            NameAndTypeInfo 5 6,
+            Utf8Info "java/lang/Object",
+            Utf8Info "<init>",
+            Utf8Info "()V",
+            Utf8Info "Code"
+            ]
+        nameConstants = [ClassInfo 9, Utf8Info name]
+        nakedClassFile = ClassFile {
+            constantPool = baseConstants ++ nameConstants,
+            accessFlags = accessPublic,
+            thisClass = 8,
+            superClass = 1,
+            fields = [],
+            methods = [],
+            attributes = []
+        }
+
+        methodsWithInjectedConstructor = injectDefaultConstructor methods
+
+        classFileWithFields = foldr fieldBuilder nakedClassFile fields
+        classFileWithMethods = foldr methodBuilder classFileWithFields methodsWithInjectedConstructor
+        classFileWithAssembledMethods = foldr methodAssembler classFileWithMethods methodsWithInjectedConstructor
+    in
+        classFileWithAssembledMethods

src/ByteCode/Generation/Builder/Field.hs

@@ -0,0 +1,46 @@
+module ByteCode.Generation.Builder.Field where
+
+import Ast
+import ByteCode.ClassFile(ClassFile (..), ConstantInfo (..), MemberInfo(..), Operation(..), Attribute(..), opcodeEncodingLength)
+import ByteCode.Generation.Generator
+import ByteCode.Constants
+import Data.List
+
+findFieldIndex :: [ConstantInfo] -> String -> Maybe Int
+findFieldIndex constants name = let
+        fieldRefNameInfos = [
+                -- we only skip one entry to get the name since the Java constant pool
+                -- is 1-indexed (why)
+                (index, constants!!(fromIntegral index + 1))
+                | (index, FieldRefInfo _ _) <- (zip [1..] constants)
+            ]
+        fieldRefNames = map (\(index, nameInfo) -> case nameInfo of
+            Utf8Info fieldName -> (index, fieldName)
+            something_else -> error ("Expected UTF8Info but got" ++ show something_else))
+                fieldRefNameInfos
+        fieldIndex = find (\(index, fieldName) -> fieldName == name) fieldRefNames
+    in case fieldIndex of
+        Just (index, _) -> Just index
+        Nothing -> Nothing
+
+
+fieldBuilder :: ClassFileBuilder VariableDeclaration
+fieldBuilder (VariableDeclaration datatype name _) input = let
+        baseIndex = 1 + length (constantPool input)
+        constants = [
+                FieldRefInfo (fromIntegral (thisClass input)) (fromIntegral (baseIndex + 1)),
+                NameAndTypeInfo (fromIntegral (baseIndex + 2)) (fromIntegral (baseIndex + 3)),
+                Utf8Info name,
+                Utf8Info (datatypeDescriptor datatype)
+            ]
+        field = MemberInfo {
+            memberAccessFlags = accessPublic,
+            memberNameIndex = (fromIntegral (baseIndex + 2)),
+            memberDescriptorIndex = (fromIntegral (baseIndex + 3)),
+            memberAttributes = []
+            }
+    in
+        input {
+            constantPool = (constantPool input) ++ constants,
+            fields = (fields input) ++ [field]
+        }

src/ByteCode/Generation/Builder/Method.hs

@@ -0,0 +1,80 @@
+module ByteCode.Generation.Builder.Method where
+
+import Ast
+import ByteCode.ClassFile(ClassFile (..), ConstantInfo (..), MemberInfo(..), Operation(..), Attribute(..), opcodeEncodingLength)
+import ByteCode.Generation.Generator
+import ByteCode.Generation.Assembler.Method
+import ByteCode.Constants
+import Data.List
+
+methodDescriptor :: MethodDeclaration -> String
+methodDescriptor (MethodDeclaration returntype _ parameters _) = let
+        parameter_types = [datatype | ParameterDeclaration datatype _ <- parameters]
+    in
+        "("
+        ++ (concat (map methodParameterDescriptor parameter_types))
+        ++ ")"
+        ++ methodParameterDescriptor returntype
+
+methodParameterDescriptor :: String -> String
+methodParameterDescriptor "void" = "V"
+methodParameterDescriptor "int" = "I"
+methodParameterDescriptor "char" = "C"
+methodParameterDescriptor "boolean" = "B"
+methodParameterDescriptor x = "L" ++ x ++ ";"
+
+memberInfoIsMethod :: [ConstantInfo] -> MemberInfo -> Bool
+memberInfoIsMethod constants info = elem '(' (memberInfoDescriptor constants info)
+
+findMethodIndex :: ClassFile -> String -> Maybe Int
+findMethodIndex classFile name = let
+        constants = constantPool classFile
+    in
+        findIndex (\method -> ((memberInfoIsMethod constants method) && (memberInfoName constants method) == name)) (methods classFile)
+
+
+methodBuilder :: ClassFileBuilder MethodDeclaration
+methodBuilder (MethodDeclaration returntype name parameters statement) input = let
+        baseIndex = 1 + length (constantPool input)
+        constants = [
+                Utf8Info name,
+                Utf8Info (methodDescriptor (MethodDeclaration returntype name parameters (Block [])))
+            ]
+
+        method = MemberInfo {
+            memberAccessFlags = accessPublic,
+            memberNameIndex = (fromIntegral baseIndex),
+            memberDescriptorIndex = (fromIntegral (baseIndex + 1)),
+            memberAttributes = []
+            }
+    in 
+        input {
+            constantPool = (constantPool input) ++ constants,
+            methods = (methods input) ++ [method]
+        }
+        
+
+
+methodAssembler :: ClassFileBuilder MethodDeclaration
+methodAssembler (MethodDeclaration returntype name parameters statement) input = let
+        methodConstantIndex = findMethodIndex input name
+    in case methodConstantIndex of
+        Nothing -> error ("Cannot find method entry in method pool for method: " ++ name)
+        Just index -> let
+                declaration = MethodDeclaration returntype name parameters statement
+                paramNames = "this" : [name | ParameterDeclaration _ name <- parameters]
+                (pre, method : post) = splitAt index (methods input)
+                (_, bytecode, _) = assembleMethod (constantPool input, [], paramNames) declaration
+                assembledMethod = method {
+                    memberAttributes = [
+                        CodeAttribute {
+                            attributeMaxStack = 420,
+                            attributeMaxLocals = 420,
+                            attributeCode = bytecode
+                        }
+                    ]
+                }
+            in
+                input {
+                    methods = pre ++ (assembledMethod : post)
+                }

src/ByteCode/Generation/Generator.hs

@@ -0,0 +1,73 @@
+module ByteCode.Generation.Generator(
+    datatypeDescriptor,
+    memberInfoName,
+    memberInfoDescriptor,
+    returnOperation,
+    binaryOperation,
+    comparisonOperation,
+    ClassFileBuilder,
+    Assembler
+) where
+
+import ByteCode.Constants
+import ByteCode.ClassFile (ClassFile (..), ConstantInfo (..), MemberInfo(..), Operation(..), Attribute(..), opcodeEncodingLength)
+import Ast
+import Data.Char
+import Data.List
+import Data.Word
+
+type ClassFileBuilder a = a -> ClassFile -> ClassFile
+type Assembler a = ([ConstantInfo], [Operation], [String]) -> a -> ([ConstantInfo], [Operation], [String])
+
+datatypeDescriptor :: String -> String
+datatypeDescriptor "void" = "V"
+datatypeDescriptor "int" = "I"
+datatypeDescriptor "char" = "C"
+datatypeDescriptor "boolean" = "B"
+datatypeDescriptor x = "L" ++ x
+
+memberInfoDescriptor :: [ConstantInfo] -> MemberInfo -> String
+memberInfoDescriptor constants MemberInfo {
+    memberAccessFlags = _,
+    memberNameIndex = _,
+    memberDescriptorIndex = descriptorIndex,
+    memberAttributes = _ } = let
+            descriptor = constants!!((fromIntegral descriptorIndex) - 1)
+        in case descriptor of
+            Utf8Info descriptorText -> descriptorText
+            _ -> ("Invalid Item at Constant pool index " ++ show descriptorIndex)
+
+
+memberInfoName :: [ConstantInfo] -> MemberInfo -> String
+memberInfoName constants MemberInfo {
+    memberAccessFlags = _,
+    memberNameIndex = nameIndex,
+    memberDescriptorIndex = _,
+    memberAttributes = _ } = let
+            name = constants!!((fromIntegral nameIndex) - 1)
+        in case name of
+            Utf8Info nameText -> nameText
+            _ -> ("Invalid Item at Constant pool index " ++ show nameIndex)
+
+
+returnOperation :: DataType -> Operation
+returnOperation dtype
+    | elem dtype ["int", "char", "boolean"] = Opireturn
+    | otherwise                             = Opareturn
+
+binaryOperation :: BinaryOperator -> Operation
+binaryOperation Addition       = Opiadd
+binaryOperation Subtraction    = Opisub
+binaryOperation Multiplication = Opimul
+binaryOperation Division       = Opidiv
+binaryOperation BitwiseAnd     = Opiand
+binaryOperation BitwiseOr      = Opior
+binaryOperation BitwiseXor     = Opixor
+
+comparisonOperation :: BinaryOperator -> Word16 -> Operation
+comparisonOperation CompareEqual          branchLocation = Opif_icmpeq branchLocation
+comparisonOperation CompareNotEqual       branchLocation = Opif_icmpne branchLocation
+comparisonOperation CompareLessThan       branchLocation = Opif_icmplt branchLocation
+comparisonOperation CompareLessOrEqual    branchLocation = Opif_icmple branchLocation
+comparisonOperation CompareGreaterThan    branchLocation = Opif_icmpgt branchLocation
+comparisonOperation CompareGreaterOrEqual branchLocation = Opif_icmpge branchLocation

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 +89,30 @@ 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)
+
+exampleNullDeclaration :: Statement
+exampleNullDeclaration = LocalVariableDeclaration (VariableDeclaration "Person" "bob" (Just NullLiteral))
+
+exampleNullDeclarationFail :: Statement
+exampleNullDeclarationFail = LocalVariableDeclaration (VariableDeclaration "int" "a" (Just NullLiteral))
+
+exampleNullAssignment :: Statement
+exampleNullAssignment = StatementExpressionStatement (Assignment (Reference "a") NullLiteral)
+
+exampleIncrement :: Statement
+exampleIncrement = StatementExpressionStatement (PostIncrement (Reference "a"))
+
 testClasses :: [Class]
 testClasses = [
     Class "Person" [
@@ -113,10 +134,12 @@ 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 +174,7 @@ 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 +212,7 @@ 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 +224,44 @@ 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
+
+    catch (do
+        print "====================================================================================="
+        evaluatedNullDeclaration <- evaluate (typeCheckStatement exampleNullDeclaration [] sampleClasses)
+        printSuccess "Type checking of null declaration completed successfully"
+        printResult "Result Null Declaration:" evaluatedNullDeclaration
+        ) handleError
+
+    catch (do
+        print "====================================================================================="
+        evaluatedNullDeclarationFail <- evaluate (typeCheckStatement exampleNullDeclarationFail [] sampleClasses)
+        printSuccess "Type checking of null declaration failed"
+        printResult "Result Null Declaration:" evaluatedNullDeclarationFail
+        ) handleError
+
+    catch (do
+        print "====================================================================================="
+        evaluatedNullAssignment <- evaluate (typeCheckStatement exampleNullAssignment [("a", "Person")] sampleClasses)
+        printSuccess "Type checking of null assignment completed successfully"
+        printResult "Result Null Assignment:" evaluatedNullAssignment
+        ) handleError
+
+    catch (do
+        print "====================================================================================="
+        evaluatedIncrement <- evaluate (typeCheckStatement exampleIncrement [("a", "int")] sampleClasses)
+        printSuccess "Type checking of increment completed successfully"
+        printResult "Result Increment:" evaluatedIncrement
+        ) handleError

src/Main.hs

@@ -2,7 +2,19 @@ module Main where
 
 import Example
 import Typecheck
+import Parser.Lexer (alexScanTokens)
+import Parser.JavaParser
+import ByteCode.Generation.Generator
+import ByteCode.Generation.Builder.Class
+import ByteCode.ClassFile
+import Data.ByteString (pack, writeFile)
 
 main = do
-    Example.runTypeCheck
+    file <- readFile "Testklasse.java"
 
+    let untypedAST = parse $ alexScanTokens file
+    let typedAST = head (typeCheckCompilationUnit untypedAST)
+    let abstractClassFile = classBuilder typedAST emptyClassFile
+    let assembledClassFile = pack (serialize abstractClassFile)
+
+    Data.ByteString.writeFile "Testklasse.class" assembledClassFile

src/Parser/JavaParser.y

@@ -1,12 +1,15 @@
 {
-module Parser.JavaParser (parse) where
+module Parser.JavaParser (parse, parseStatement, parseExpression) where
 import Ast
 import Parser.Lexer
 }
 
 %name parse
+%name parseStatement statement
+%name parseExpression expression
 %tokentype { Token }
 %error { parseError }
+%errorhandlertype explist
   
 %token 
         BOOLEAN { BOOLEAN }
@@ -41,7 +44,6 @@ import Parser.Lexer
         JNULL { NULLLITERAL }
         BOOLLITERAL { BOOLLITERAL $$ }
         DIV { DIV }
-        LOGICALOR { OR }
         NOTEQUAL { NOTEQUAL }
         INSTANCEOF { INSTANCEOF }
         ANDEQUAL { ANDEQUAL }
@@ -80,17 +82,17 @@ compilationunit  : typedeclarations { $1 }
 typedeclarations : typedeclaration { [$1] }
                  | typedeclarations typedeclaration { $1 ++ [$2] }
 
-name             : qualifiedname { }
-                 | simplename { }
+name             : simplename { Reference $1 }
+                 | qualifiedname { $1 }
 
 typedeclaration  : classdeclaration { $1 }
 
-qualifiedname    : name  DOT IDENTIFIER { }
+qualifiedname    : name  DOT IDENTIFIER { BinaryOperation NameResolution $1 (Reference $3) }
 
-simplename       : IDENTIFIER { }
+simplename       : IDENTIFIER { $1 }
 
 classdeclaration : CLASS IDENTIFIER classbody { case $3 of (methods, fields) -> Class $2 methods fields }
-                --  | modifiers CLASS IDENTIFIER classbody { case $4 of (methods, fields) -> Class $3 methods fields }
+                 | modifiers CLASS IDENTIFIER classbody { case $4 of (methods, fields) -> Class $3 methods fields }
 
 classbody        : LBRACKET RBRACKET  { ([], []) }
                  | LBRACKET classbodydeclarations  RBRACKET { $2 }
@@ -103,11 +105,11 @@ classbodydeclarations :  classbodydeclaration {
                         MethodDecl method -> ([method], [])
                         FieldDecls fields -> ([], fields)
                         }
-                --  | classbodydeclarations classbodydeclaration {
-                --         case ($1, $2) of
-                --         ((methods, fields), MethodDecl method) -> ((methods ++ [method]), fields)
-                --         ((methods, fields), FieldDecl field) -> (methods, (fields ++ [field]))
-                --         }
+                 | classbodydeclarations classbodydeclaration {
+                        case ($1, $2) of
+                        ((methods, fields), MethodDecl method) -> ((methods ++ [method]), fields)
+                        ((methods, fields), FieldDecls newFields) -> (methods, (fields ++ newFields))
+                        }
 
 modifier         : PUBLIC { }
                  | PROTECTED { }
@@ -115,54 +117,54 @@ modifier         : PUBLIC { }
                  | STATIC { }
                  | ABSTRACT { }
 
-classtype        : classorinterfacetype{ }
+classtype        : classorinterfacetype { $1 }
 
 classbodydeclaration : classmemberdeclaration { $1 }
-                --  | constructordeclaration { FieldDecl $ VariableDeclaration "int" "a" Nothing }  -- TODO
+                 | constructordeclaration { $1 }
 
-classorinterfacetype : name{ }
+classorinterfacetype : simplename { $1 }
 
 classmemberdeclaration : fielddeclaration { $1 }
-                --  | methoddeclaration { }
+                 | methoddeclaration { $1 }
 
-constructordeclaration : constructordeclarator constructorbody { }
-                 |  modifiers constructordeclarator constructorbody { }
+constructordeclaration : constructordeclarator constructorbody { MethodDecl $ MethodDeclaration "void" "<init>" $1 $2 }
+                 |  modifiers constructordeclarator constructorbody { MethodDecl $ MethodDeclaration "void" "<init>" $2 $3 }
 
 fielddeclaration : type variabledeclarators  SEMICOLON { FieldDecls $ map (convertDeclarator $1) $2 }
-                --   | modifiers type variabledeclarators  SEMICOLON {}
+                 | modifiers type variabledeclarators  SEMICOLON { FieldDecls $ map (convertDeclarator $2) $3 }
 
-methoddeclaration : methodheader methodbody { }
+methoddeclaration : methodheader methodbody { case $1 of (returnType, (name, parameters)) -> MethodDecl (MethodDeclaration returnType name parameters $2) }
 
-block            : LBRACKET   RBRACKET { }
-                 | LBRACKET  blockstatements  RBRACKET { }
+block            : LBRACKET   RBRACKET { Block [] }
+                 | LBRACKET  blockstatements  RBRACKET { Block $2 }
 
-constructordeclarator :  simplename LBRACE  RBRACE  { }
-                 |  simplename LBRACE formalparameterlist RBRACE  { }
+constructordeclarator :  simplename LBRACE  RBRACE  { [] }
+                 |  simplename LBRACE formalparameterlist RBRACE  { $3 }
 
-constructorbody  : LBRACKET RBRACKET { }
-                 | LBRACKET explicitconstructorinvocation  RBRACKET { }
-                 | LBRACKET blockstatements  RBRACKET { }
-                 | LBRACKET explicitconstructorinvocation blockstatements RBRACKET { }
+constructorbody  : LBRACKET RBRACKET { Block [] }
+                --  | LBRACKET explicitconstructorinvocation  RBRACKET { }
+                 | LBRACKET blockstatements  RBRACKET { Block $2 }
+                --  | LBRACKET explicitconstructorinvocation blockstatements RBRACKET { }
 
-methodheader         : type methoddeclarator { }
-                 | modifiers type methoddeclarator { }
-                 | VOID methoddeclarator { }
-                 | modifiers VOID methoddeclarator { }
+methodheader     : type  methoddeclarator { ($1, $2) }
+                 | modifiers type methoddeclarator { ($2, $3) }
+                 | VOID methoddeclarator { ("void", $2) }
+                 | modifiers VOID methoddeclarator { ("void", $3)}
 
 type             : primitivetype { $1 }
-                --  | referencetype { }
+                 | referencetype { $1 }
 
 variabledeclarators : variabledeclarator { [$1] }
-                --  | variabledeclarators  COMMA  variabledeclarator { $1 ++ [$3] }
+                 | variabledeclarators  COMMA  variabledeclarator { $1 ++ [$3] }
 
-methodbody       : block { }
-                 | SEMICOLON { }
+methodbody       : block { $1 }
+                 | SEMICOLON { Block [] }
 
-blockstatements  : blockstatement { }
-                 | blockstatements blockstatement { }
+blockstatements  : blockstatement { $1 }
+                 | blockstatements blockstatement { $1 ++ $2}
 
-formalparameterlist : formalparameter { }
-                 | formalparameterlist  COMMA  formalparameter{ }
+formalparameterlist : formalparameter { [$1] }
+                 | formalparameterlist  COMMA  formalparameter { $1 ++ [$3] }
 
 explicitconstructorinvocation : THIS LBRACE  RBRACE   SEMICOLON  { }
                  | THIS LBRACE argumentlist  RBRACE   SEMICOLON  { }
@@ -170,192 +172,196 @@ explicitconstructorinvocation : THIS LBRACE  RBRACE   SEMICOLON  { }
 classtypelist    : classtype { }
                  | classtypelist  COMMA  classtype { }
 
-methoddeclarator : IDENTIFIER LBRACE  RBRACE  { }
-                 | IDENTIFIER LBRACE formalparameterlist  RBRACE  { }
+methoddeclarator : IDENTIFIER LBRACE  RBRACE  { ($1, []) }
+                 | IDENTIFIER LBRACE formalparameterlist  RBRACE  { ($1, $3) }
 
 primitivetype    : BOOLEAN { "boolean" }
                  | numerictype { $1 }
 
-referencetype    : classorinterfacetype { }
+referencetype    : classorinterfacetype { $1 }
 
 
 variabledeclarator : variabledeclaratorid { Declarator $1 Nothing }
-                --  | variabledeclaratorid ASSIGN variableinitializer { Declarator $1 Nothing } -- TODO
+                 | variabledeclaratorid ASSIGN variableinitializer { Declarator $1 (Just $3) }
 
-blockstatement         : localvariabledeclarationstatement { }
-                 | statement  { }
+blockstatement         : localvariabledeclarationstatement { $1 } -- expected type statement
+                 | statement  { $1 }
 
-formalparameter  : type variabledeclaratorid { }
+formalparameter  : type variabledeclaratorid { ParameterDeclaration $1 $2 }
 
-argumentlist     : expression { }
-                 | argumentlist  COMMA  expression { }
+argumentlist     : expression { [$1] }
+                 | argumentlist  COMMA  expression { $1 ++ [$3] }
 
 numerictype      : integraltype { $1 }
 
 variabledeclaratorid : IDENTIFIER { $1 }
 
-variableinitializer  : expression { }
+variableinitializer  : expression { $1 }
 
-localvariabledeclarationstatement : localvariabledeclaration  SEMICOLON  { }
+localvariabledeclarationstatement : localvariabledeclaration  SEMICOLON  { $1 }
 
-statement        : statementwithouttrailingsubstatement{ }
-                 | ifthenstatement { }
-                 | ifthenelsestatement { }
-                 | whilestatement { }
+statement        : statementwithouttrailingsubstatement{ $1 }  -- statement returns a list of statements
+                 | ifthenstatement { [$1] }
+                 | ifthenelsestatement { [$1] }
+                 | whilestatement { [$1] }
                                      
 
-expression       : assignmentexpression { }
+expression       : assignmentexpression { $1 }
 
 integraltype     : INT  { "int" }
                  | CHAR { "char" }
 
-localvariabledeclaration : type variabledeclarators { }
+localvariabledeclaration : type variabledeclarators { map LocalVariableDeclaration $ map (convertDeclarator $1) $2 }
 
-statementwithouttrailingsubstatement : block { }
-                 | emptystatement { }
-                 | expressionstatement { }
-                 | returnstatement { }
+statementwithouttrailingsubstatement : block { [$1] }
+                 | emptystatement { [] }
+                 | expressionstatement { [$1] }
+                 | returnstatement { [$1] }
 
-ifthenstatement  : IF LBRACE expression  RBRACE  statement { }
+ifthenstatement  : IF LBRACE expression  RBRACE  statement { If $3 (Block $5) Nothing }
 
-ifthenelsestatement : IF LBRACE expression  RBRACE statementnoshortif ELSE statement  { }
+ifthenelsestatement : IF LBRACE expression  RBRACE statementnoshortif ELSE statement { If $3 (Block $5)  (Just (Block $7)) }
 
-whilestatement   : WHILE LBRACE expression  RBRACE  statement { }
+whilestatement   : WHILE LBRACE expression  RBRACE  statement { While $3 (Block $5) }
 
-assignmentexpression : conditionalexpression { }
-                 |  assignment{ }
+assignmentexpression : conditionalexpression { $1 }
+                 | assignment { StatementExpressionExpression $1 }
 
-emptystatement         :  SEMICOLON  { }
+emptystatement         :  SEMICOLON  { Block [] }
 
-expressionstatement : statementexpression  SEMICOLON { }
+expressionstatement : statementexpression  SEMICOLON { StatementExpressionStatement $1 }
 
-returnstatement  : RETURN  SEMICOLON  { }
-                 | RETURN expression  SEMICOLON { }
+returnstatement  : RETURN  SEMICOLON  { Return Nothing }
+                 | RETURN expression  SEMICOLON { Return $ Just $2 }
 
-statementnoshortif : statementwithouttrailingsubstatement { }
-                 | ifthenelsestatementnoshortif { }
-                 | whilestatementnoshortif { }
+statementnoshortif : statementwithouttrailingsubstatement { $1 }
+                --  | ifthenelsestatementnoshortif { }
+                --  | whilestatementnoshortif { }
 
-conditionalexpression : conditionalorexpression { }
-                 | conditionalorexpression QUESMARK expression  COLON  conditionalexpression { }
+conditionalexpression : conditionalorexpression { $1 }
+                --  | conditionalorexpression QUESMARK expression  COLON  conditionalexpression { }
 
-assignment       :lefthandside assignmentoperator assignmentexpression { }
+assignment       : lefthandside assignmentoperator assignmentexpression {
+                        case $2 of
+                        Nothing -> Assignment $1 $3
+                        Just operator -> Assignment $1 (BinaryOperation operator $1 $3)
+                        }
         
 
-statementexpression : assignment { }
-                 | preincrementexpression { }
-                 | predecrementexpression { }
-                 | postincrementexpression { }
-                 | postdecrementexpression { }
-                 | methodinvocation { }
-                 | classinstancecreationexpression { }
+statementexpression : assignment { $1 }
+                 | preincrementexpression { $1 }
+                 | predecrementexpression { $1 }
+                 | postincrementexpression { $1 }
+                 | postdecrementexpression { $1 }
+                 | methodinvocation { $1 }
+                 | classinstancecreationexpression { $1 }
 
 ifthenelsestatementnoshortif :IF LBRACE expression  RBRACE  statementnoshortif
                               ELSE statementnoshortif  { }
 
 whilestatementnoshortif : WHILE LBRACE expression  RBRACE  statementnoshortif { }
 
-conditionalorexpression : conditionalandexpression { }
-                 | conditionalorexpression LOGICALOR conditionalandexpression{ }
+conditionalorexpression : conditionalandexpression { $1 }
+                --  | conditionalorexpression LOGICALOR conditionalandexpression{ }
 
-lefthandside     : name { }
+lefthandside     : name { $1 }
 
-assignmentoperator : ASSIGN{ }
-                 | TIMESEQUAL { }
-                 | DIVIDEEQUAL { }
-                 | MODULOEQUAL { }
-                 | PLUSEQUAL { }
-                 | MINUSEQUAL { }
-                 | SHIFTLEFTEQUAL { }
-                 | SIGNEDSHIFTRIGHTEQUAL { }
-                 | UNSIGNEDSHIFTRIGHTEQUAL { }
-                 | ANDEQUAL { }
-                 | XOREQUAL { }
-                 | OREQUAL{ }
+assignmentoperator : ASSIGN { Nothing }
+                 | TIMESEQUAL { Just Multiplication }
+                 | DIVIDEEQUAL { Just Division }
+                 | MODULOEQUAL { Just Modulo }
+                 | PLUSEQUAL { Just Addition }
+                 | MINUSEQUAL { Just Subtraction }
+                --  | SHIFTLEFTEQUAL { }
+                --  | SIGNEDSHIFTRIGHTEQUAL { }
+                --  | UNSIGNEDSHIFTRIGHTEQUAL { }
+                 | ANDEQUAL { Just BitwiseAnd }
+                 | XOREQUAL { Just BitwiseXor }
+                 | OREQUAL{ Just BitwiseOr }
 
-preincrementexpression : INCREMENT unaryexpression { }
+preincrementexpression : INCREMENT unaryexpression { PreIncrement $2 }
 
-predecrementexpression : DECREMENT unaryexpression { }
+predecrementexpression : DECREMENT unaryexpression { PreDecrement $2 }
 
-postincrementexpression : postfixexpression INCREMENT { }
+postincrementexpression : postfixexpression INCREMENT { PostIncrement $1 }
 
-postdecrementexpression : postfixexpression DECREMENT { }
+postdecrementexpression : postfixexpression DECREMENT { PostDecrement $1 }
 
-methodinvocation : name LBRACE   RBRACE  { }
-                 | name LBRACE argumentlist RBRACE { }
-                 | primary  DOT IDENTIFIER LBRACE RBRACE  { }
-                 | primary  DOT IDENTIFIER LBRACE argumentlist  RBRACE  { }
+methodinvocation : simplename LBRACE   RBRACE  { MethodCall (Reference "this") $1 []  }
+                 | simplename LBRACE argumentlist RBRACE { MethodCall (Reference "this") $1 $3 }
+                 | primary  DOT IDENTIFIER LBRACE RBRACE  { MethodCall $1 $3 [] }
+                 | primary  DOT IDENTIFIER LBRACE argumentlist  RBRACE  { MethodCall $1 $3 $5 }
      
-classinstancecreationexpression : NEW classtype LBRACE   RBRACE  { }
-                 | NEW classtype LBRACE  argumentlist  RBRACE  { }
+classinstancecreationexpression : NEW classtype LBRACE   RBRACE  { ConstructorCall $2 [] }
+                 | NEW classtype LBRACE  argumentlist  RBRACE  { ConstructorCall $2 $4 }
 
-conditionalandexpression : inclusiveorexpression { }
+conditionalandexpression : inclusiveorexpression { $1 }
 
-fieldaccess      : primary  DOT IDENTIFIER { }
+fieldaccess      : primary  DOT IDENTIFIER { BinaryOperation NameResolution $1 (Reference $3) }
 
-unaryexpression         : preincrementexpression { }
-                 | predecrementexpression { }
-                 | PLUS unaryexpression { }
-                 | MINUS unaryexpression { }
-                 | unaryexpressionnotplusminus { }
+unaryexpression         : unaryexpressionnotplusminus { $1 }
+                 | predecrementexpression { StatementExpressionExpression $1 }
+                 | PLUS unaryexpression { $2 }
+                 | MINUS unaryexpression { UnaryOperation Minus $2 }
+                 | preincrementexpression { StatementExpressionExpression $1 }
 
-postfixexpression : primary { }
-                 | name { }
-                 | postincrementexpression { }
-                 | postdecrementexpression{ }
+postfixexpression : primary { $1 }
+                 | name { $1 }
+                 | postincrementexpression { StatementExpressionExpression $1 }
+                 | postdecrementexpression { StatementExpressionExpression $1 }
 
-primary                 : primarynonewarray { }
+primary                 : primarynonewarray { $1 }
 
-inclusiveorexpression : exclusiveorexpression { }
-                 | inclusiveorexpression OR exclusiveorexpression { }
+inclusiveorexpression : exclusiveorexpression { $1 }
+                 | inclusiveorexpression OR exclusiveorexpression { BinaryOperation Or $1 $3 }
 
-primarynonewarray : literal { }
-                 | THIS { }
-                 | LBRACE expression RBRACE  { }
-                 | classinstancecreationexpression { }
-                 | fieldaccess { }
-                 | methodinvocation { }
+primarynonewarray : literal { $1 }
+                 | THIS { Reference "this" }
+                 | LBRACE expression RBRACE  { $2 }
+                 | classinstancecreationexpression { StatementExpressionExpression $1 }
+                 | fieldaccess { $1 }
+                 | methodinvocation { StatementExpressionExpression $1 }
 
-unaryexpressionnotplusminus : postfixexpression { }
-                 | TILDE unaryexpression { }
-                 | EXCLMARK unaryexpression { }
-                 | castexpression{ }
+unaryexpressionnotplusminus : postfixexpression { $1 }
+                --  | TILDE unaryexpression { }
+                 | EXCLMARK unaryexpression { UnaryOperation Not $2 }
+                --  | castexpression{ }
 
-exclusiveorexpression : andexpression { }
-                 | exclusiveorexpression XOR andexpression { }
+exclusiveorexpression : andexpression { $1 }
+                 | exclusiveorexpression XOR andexpression { BinaryOperation BitwiseXor $1 $3 }
 
-literal          : INTLITERAL { }
-                 | BOOLLITERAL { }
-                 | CHARLITERAL { }
-                 | JNULL { }
+literal          : INTLITERAL { IntegerLiteral $1 }
+                 | BOOLLITERAL { BooleanLiteral $1 }
+                 | CHARLITERAL { CharacterLiteral $1 }
+                 | JNULL { NullLiteral }
 
 castexpression         : LBRACE  primitivetype  RBRACE  unaryexpression { }
                   | LBRACE  expression  RBRACE  unaryexpressionnotplusminus{ }
 
-andexpression    : equalityexpression { }
-                 | andexpression AND equalityexpression { }
+andexpression    : equalityexpression { $1 }
+                 | andexpression AND equalityexpression { BinaryOperation And $1 $3 }
 
-equalityexpression : relationalexpression { }
-                 | equalityexpression EQUAL relationalexpression { }
-                 | equalityexpression NOTEQUAL relationalexpression { }
+equalityexpression : relationalexpression { $1 }
+                 | equalityexpression EQUAL relationalexpression { BinaryOperation CompareEqual $1 $3 }
+                 | equalityexpression NOTEQUAL relationalexpression { BinaryOperation CompareNotEqual $1 $3 }
 
-relationalexpression : shiftexpression { }
-                 | relationalexpression LESS shiftexpression { }
-                 | relationalexpression GREATER shiftexpression { }
-                 | relationalexpression LESSEQUAL shiftexpression { }
-                 | relationalexpression GREATEREQUAL shiftexpression { }
-                 | relationalexpression INSTANCEOF referencetype { }
+relationalexpression : shiftexpression { $1 }
+                 | relationalexpression LESS shiftexpression { BinaryOperation CompareLessThan $1 $3 }
+                 | relationalexpression GREATER shiftexpression { BinaryOperation CompareGreaterThan $1 $3 }
+                 | relationalexpression LESSEQUAL shiftexpression { BinaryOperation CompareLessOrEqual $1 $3 }
+                 | relationalexpression GREATEREQUAL shiftexpression { BinaryOperation CompareGreaterOrEqual $1 $3 }
+                --  | relationalexpression INSTANCEOF referencetype { }
 
-shiftexpression         : additiveexpression { }
+shiftexpression         : additiveexpression { $1 }
 
-additiveexpression : multiplicativeexpression { }
-                 | additiveexpression PLUS multiplicativeexpression { }
-                 | additiveexpression MINUS multiplicativeexpression { }
+additiveexpression : multiplicativeexpression { $1 }
+                 | additiveexpression PLUS multiplicativeexpression { BinaryOperation Addition $1 $3 }
+                 | additiveexpression MINUS multiplicativeexpression { BinaryOperation Subtraction $1 $3 }
 
-multiplicativeexpression : unaryexpression { }
-                 | multiplicativeexpression MUL unaryexpression { }
-                 | multiplicativeexpression DIV unaryexpression { }
-                 | multiplicativeexpression MOD unaryexpression { }
+multiplicativeexpression : unaryexpression { $1 }
+                 | multiplicativeexpression MUL unaryexpression { BinaryOperation Multiplication $1 $3 }
+                 | multiplicativeexpression DIV unaryexpression { BinaryOperation Division $1 $3 }
+                 | multiplicativeexpression MOD unaryexpression { BinaryOperation Modulo $1 $3 }
 
 
 {
@@ -365,13 +371,13 @@ data MethodOrFieldDeclaration = MethodDecl MethodDeclaration
 
 data Declarator = Declarator Identifier (Maybe Expression)
 
--- convertDeclaratorList :: [DataType] -> MethodOrFieldDeclaration
--- convertDeclaratorList = FieldDecls $ map 
-
 convertDeclarator :: DataType -> Declarator -> VariableDeclaration
 convertDeclarator dataType (Declarator id assigment) = VariableDeclaration dataType id assigment
 
-parseError :: [Token] -> a
-parseError msg = error ("Parse error: " ++ show msg)
+data StatementWithoutSub =  Statement
+
+
+parseError :: ([Token], [String]) -> a
+parseError (errortoken, expected) = error ("parse error on token: " ++ show errortoken ++ "\nexpected one of:      " ++ show expected)
 
 }

src/Parser/Lexer.x

@@ -72,7 +72,7 @@ tokens :-
     -- end keywords
     $JavaLetter$JavaLetterOrDigit*  { \s -> IDENTIFIER s }
     -- Literals
-    [1-9]([0-9\_]*[0-9])* { \s -> case readMaybe $ filter ((/=) '_') s of Just a -> INTEGERLITERAL a; Nothing -> error ("failed to parse INTLITERAL " ++ s) }
+    [0-9]([0-9\_]*[0-9])* { \s -> case readMaybe $ filter ((/=) '_') s of Just a -> INTEGERLITERAL a; Nothing -> error ("failed to parse INTLITERAL " ++ s) }
     "'"."'" { \s -> case (s) of _ : c : _ -> CHARLITERAL c; _ -> error ("failed to parse CHARLITERAL " ++ s) }
     -- separators
     "(" { \_ -> LBRACE }

src/Typecheck.hs

@@ -9,25 +9,42 @@ typeCheckCompilationUnit classes = map (`typeCheckClass` classes) classes
 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]
-        methodEntries = [(methodName, className) | MethodDeclaration _ methodName _ _ <- methods]
-        initalSymTab = ("this", className) : classFields ++ methodEntries
+        -- Fields and methods dont need to be added to the symtab because they are looked upon automatically under "this" 
+        -- if its not a declared local variable. Also shadowing wouldnt be possible then.
+        initalSymTab = [("this", className)]
         checkedMethods = map (\method -> typeCheckMethodDeclaration method initalSymTab classes) methods
-    in Class className checkedMethods fields
+        checkedFields = map (\field -> typeCheckVariableDeclaration field initalSymTab classes) fields
+    in Class className checkedMethods checkedFields
 
 typeCheckMethodDeclaration :: MethodDeclaration -> [(Identifier, DataType)] -> [Class] -> MethodDeclaration
-typeCheckMethodDeclaration (MethodDeclaration retType name params body) classFields classes =
+typeCheckMethodDeclaration (MethodDeclaration retType name params body) symtab classes =
     let
-        -- Combine class fields with method parameters to form the initial symbol table for the method
         methodParams = [(identifier, dataType) | ParameterDeclaration dataType identifier <- params]
-        initialSymtab = classFields ++ methodParams
+        initialSymtab = ("thisMeth", retType) : symtab ++ methodParams
         checkedBody = typeCheckStatement body initialSymtab classes
         bodyType = getTypeFromStmt checkedBody
-        -- Check if the type of the body matches the declared return type
-    in if bodyType == retType || (bodyType == "void" && retType == "void")
+    in if bodyType == retType || (bodyType == "void" && retType == "void") || (bodyType == "null" && isObjectType retType) || isSubtype bodyType retType classes
        then MethodDeclaration retType name params checkedBody
-       else error $ "Return type mismatch in method " ++ name ++ ": expected " ++ retType ++ ", found " ++ bodyType
+       else error $ "Method Declaration: Return type mismatch in method " ++ name ++ ": expected " ++ retType ++ ", found " ++ bodyType
+
+typeCheckVariableDeclaration :: VariableDeclaration -> [(Identifier, DataType)] -> [Class] -> VariableDeclaration
+typeCheckVariableDeclaration (VariableDeclaration dataType identifier maybeExpr) symtab classes =
+    let
+        -- Ensure the type is valid (either a primitive type or a valid class name)
+        validType = dataType `elem` ["int", "boolean", "char"] || isUserDefinedClass dataType classes
+        -- Ensure no redefinition in the same scope
+        redefined = any ((== identifier) . snd) symtab
+        -- Type check the initializer expression if it exists
+        checkedExpr = fmap (\expr -> typeCheckExpression expr symtab classes) maybeExpr
+        exprType = fmap getTypeFromExpr checkedExpr
+    in case (validType, redefined, exprType) of
+        (False, _, _) -> error $ "Type '" ++ dataType ++ "' is not a valid type for variable '" ++ identifier ++ "'"
+        (_, True, _) -> error $ "Variable '" ++ identifier ++ "' is redefined in the same scope"
+        (_, _, Just t)
+            | t == "null" && isObjectType dataType -> VariableDeclaration dataType identifier checkedExpr
+            | t /= dataType -> error $ "Type mismatch in declaration of '" ++ identifier ++ "': expected " ++ dataType ++ ", found " ++ t
+            | otherwise -> VariableDeclaration dataType identifier checkedExpr
+        (_, _, Nothing) -> VariableDeclaration dataType identifier checkedExpr
 
 -- ********************************** Type Checking: Expressions **********************************
 
@@ -37,118 +54,47 @@ 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
-   in TypedExpression type' (Reference id)
+  case lookup id symtab of
+    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]
+              -- this case only happens when its a field of its own class so the implicit this will be converted to explicit this
+              in case fieldTypes of
+                [fieldType] -> TypedExpression fieldType (BinaryOperation NameResolution (TypedExpression className (LocalVariable "this")) (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 ->
-          if type1 == "int" && type2 == "int"
-            then
-              TypedExpression "int" (BinaryOperation op expr1' expr2')
-            else
-              error "Addition operation requires two operands of type int"
-        Subtraction ->
-          if type1 == "int" && type2 == "int"
-            then
-              TypedExpression "int" (BinaryOperation op expr1' expr2')
-            else
-              error "Subtraction operation requires two operands of type int"
-        Multiplication ->
-          if type1 == "int" && type2 == "int"
-            then
-              TypedExpression "int" (BinaryOperation op expr1' expr2')
-            else
-              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"
+        Addition -> checkArithmeticOperation op expr1' expr2' type1 type2 resultType
+        Subtraction -> checkArithmeticOperation op expr1' expr2' type1 type2 resultType
+        Multiplication -> checkArithmeticOperation op expr1' expr2' type1 type2 resultType
+        Division -> checkArithmeticOperation op expr1' expr2' type1 type2 resultType
+        Modulo -> checkArithmeticOperation op expr1' expr2' type1 type2 resultType
+        BitwiseAnd -> checkBitwiseOperation op expr1' expr2' type1 type2
+        BitwiseOr -> checkBitwiseOperation op expr1' expr2' type1 type2
+        BitwiseXor -> checkBitwiseOperation op expr1' expr2' type1 type2
+        CompareLessThan -> checkComparisonOperation op expr1' expr2' type1 type2
+        CompareLessOrEqual -> checkComparisonOperation op expr1' expr2' type1 type2
+        CompareGreaterThan -> checkComparisonOperation op expr1' expr2' type1 type2
+        CompareGreaterOrEqual -> checkComparisonOperation op expr1' expr2' type1 type2
+        CompareEqual -> checkEqualityOperation op expr1' expr2' type1 type2
+        CompareNotEqual -> checkEqualityOperation op expr1' expr2' type1 type2
+        And -> checkLogicalOperation op expr1' expr2' type1 type2
+        Or -> checkLogicalOperation op expr1' expr2' type1 type2
+        NameResolution -> resolveNameResolution expr1' expr2 symtab classes
 
 typeCheckExpression (UnaryOperation op expr) symtab classes =
   let expr' = typeCheckExpression expr symtab classes
@@ -161,11 +107,11 @@ typeCheckExpression (UnaryOperation op expr) symtab classes =
             else
               error "Logical NOT operation requires an operand of type boolean"
         Minus ->
-          if type' == "int"
+          if type' == "int" || type' == "char"
             then
-              TypedExpression "int" (UnaryOperation op expr')
+              TypedExpression type' (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"
 
 typeCheckExpression (StatementExpressionExpression stmtExpr) symtab classes =
   let stmtExpr' = typeCheckStatementExpression stmtExpr symtab classes
@@ -174,23 +120,29 @@ 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
-   in if type' == type''
-        then
-          TypedStatementExpression type' (Assignment id expr')
+      type'' = getTypeFromExpr ref'
+  in
+    if type'' == type' || (type' == "null" && isObjectType type'') then
+      TypedStatementExpression type'' (Assignment ref' expr')
     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
     Nothing -> error $ "Class '" ++ className ++ "' not found."
     Just (Class _ methods fields) ->
-      -- Constructor needs the same name as the class
-      case find (\(MethodDeclaration retType name params _) -> name == className && retType == className) methods of
-        Nothing -> error $ "No valid constructor found for class '" ++ className ++ "'."
+      -- Find constructor matching the class name with void return type
+      case find (\(MethodDeclaration retType name params _) -> name == "<init>" && retType == "void") methods of
+        -- If no constructor is found, assume standard constructor with no parameters
+        Nothing ->
+          if null args then
+            TypedStatementExpression className (ConstructorCall className args)
+          else
+            error $ "No valid constructor found for class '" ++ className ++ "', but arguments were provided."
         Just (MethodDeclaration _ _ params _) ->
           let
             args' = map (\arg -> typeCheckExpression arg symtab classes) args
@@ -234,20 +186,62 @@ typeCheckStatementExpression (MethodCall expr methodName args) symtab classes =
                 Nothing -> error $ "Class for object type '" ++ objType ++ "' not found."
         _ -> error "Invalid object type for method call. Object must have a class type."
 
+typeCheckStatementExpression (PostIncrement expr) symtab classes =
+  let expr' = typeCheckExpression expr symtab classes
+      type' = getTypeFromExpr expr'
+   in if type' == "int" || type' == "char"
+        then
+          TypedStatementExpression type' (PostIncrement expr')
+        else
+          error "Post-increment operation requires an operand of type int or char"
+
+typeCheckStatementExpression (PostDecrement expr) symtab classes =
+  let expr' = typeCheckExpression expr symtab classes
+      type' = getTypeFromExpr expr'
+   in if type' == "int" || type' == "char"
+        then
+          TypedStatementExpression type' (PostDecrement expr')
+        else
+          error "Post-decrement operation requires an operand of type int or char"
+
+typeCheckStatementExpression (PreIncrement expr) symtab classes =
+  let expr' = typeCheckExpression expr symtab classes
+      type' = getTypeFromExpr expr'
+   in if type' == "int" || type' == "char"
+        then
+          TypedStatementExpression type' (PreIncrement expr')
+        else
+          error "Pre-increment operation requires an operand of type int or char"
+
+typeCheckStatementExpression (PreDecrement expr) symtab classes =
+  let expr' = typeCheckExpression expr symtab classes
+      type' = getTypeFromExpr expr'
+   in if type' == "int" || type' == "char"
+        then
+          TypedStatementExpression type' (PreDecrement expr')
+        else
+          error "Pre-decrement operation requires an operand of type int or char"
+
 -- ********************************** Type Checking: Statements **********************************
 
 typeCheckStatement :: Statement -> [(Identifier, DataType)] -> [Class] -> Statement
 typeCheckStatement (If cond thenStmt elseStmt) symtab classes =
-  let cond' = typeCheckExpression cond symtab classes
+  let
+    cond' = typeCheckExpression cond symtab classes
     thenStmt' = typeCheckStatement thenStmt symtab classes
-      elseStmt' = case elseStmt of
-        Just stmt -> Just (typeCheckStatement stmt symtab classes)
-        Nothing   -> Nothing
+    elseStmt' = fmap (\stmt -> typeCheckStatement stmt symtab classes) elseStmt
+
+    thenType = getTypeFromStmt thenStmt'
+    elseType = maybe "void" getTypeFromStmt elseStmt'
+
+    ifType = if thenType == "void" || elseType == "void"
+             then "void"
+             else unifyReturnTypes thenType elseType
+
   in if getTypeFromExpr cond' == "boolean"
-        then
-          TypedStatement (getTypeFromStmt thenStmt') (If cond' thenStmt' elseStmt')
-        else
-          error "If condition must be of type boolean"
+       then TypedStatement ifType (If cond' thenStmt' elseStmt')
+       else error "If condition must be of type boolean"
+
 
 typeCheckStatement (LocalVariableDeclaration (VariableDeclaration dataType identifier maybeExpr)) symtab classes =
     -- Check for redefinition in the current scope
@@ -258,8 +252,12 @@ typeCheckStatement (LocalVariableDeclaration (VariableDeclaration dataType ident
         let checkedExpr = fmap (\expr -> typeCheckExpression expr symtab classes) maybeExpr
             exprType = fmap getTypeFromExpr checkedExpr
         in case exprType of
-            Just t | t /= dataType -> error $ "Type mismatch in declaration of '" ++ identifier ++ "': expected " ++ dataType ++ ", found " ++ t
-            _ -> TypedStatement dataType (LocalVariableDeclaration (VariableDeclaration dataType identifier checkedExpr))
+            Just t
+                | t == "null" && isObjectType dataType ->
+                    TypedStatement dataType (LocalVariableDeclaration (VariableDeclaration dataType identifier checkedExpr))
+                | t /= dataType -> error $ "Type mismatch in declaration of '" ++ identifier ++ "': expected " ++ dataType ++ ", found " ++ t
+                | otherwise -> TypedStatement dataType (LocalVariableDeclaration (VariableDeclaration dataType identifier checkedExpr))
+            Nothing -> TypedStatement dataType (LocalVariableDeclaration (VariableDeclaration dataType identifier checkedExpr))
 
 typeCheckStatement (While cond stmt) symtab classes =
   let cond' = typeCheckExpression cond symtab classes
@@ -273,36 +271,46 @@ typeCheckStatement (While cond stmt) symtab classes =
 typeCheckStatement (Block statements) symtab classes =
     let
         processStatements (accSts, currentSymtab, types) stmt =
+            case stmt of
+                LocalVariableDeclaration (VariableDeclaration dataType identifier maybeExpr) ->
+                    let
+                        alreadyDefined = any (\(id, _) -> id == identifier) currentSymtab
+                        newSymtab = if alreadyDefined
+                                    then error ("Variable " ++ identifier ++ " already defined in this scope.")
+                                    else (identifier, dataType) : currentSymtab
+                        checkedExpr = fmap (\expr -> typeCheckExpression expr currentSymtab classes) maybeExpr
+                        checkedStmt = typeCheckStatement stmt newSymtab classes
+                    in (accSts ++ [checkedStmt], newSymtab, types)
+
+                _ ->
                     let
                         checkedStmt = typeCheckStatement stmt currentSymtab classes
                         stmtType = getTypeFromStmt checkedStmt
                     in case stmt of
-                LocalVariableDeclaration (VariableDeclaration dataType identifier maybeExpr) ->
-                    let
-                        checkedExpr = fmap (\expr -> typeCheckExpression expr currentSymtab classes) maybeExpr
-                        newSymtab = (identifier, dataType) : currentSymtab
-                    in (accSts ++ [checkedStmt], newSymtab, types)
-
                         If {} -> (accSts ++ [checkedStmt], currentSymtab, if stmtType /= "void" then types ++ [stmtType] else types)
                         While _ _ -> (accSts ++ [checkedStmt], currentSymtab, if stmtType /= "void" then types ++ [stmtType] else types)
                         Return _ -> (accSts ++ [checkedStmt], currentSymtab, if stmtType /= "void" then types ++ [stmtType] else types)
+                        Block _ -> (accSts ++ [checkedStmt], currentSymtab, if stmtType /= "void" then types ++ [stmtType] else types)
                         _ -> (accSts ++ [checkedStmt], currentSymtab, types)
 
         -- Initial accumulator: empty statements list, initial symbol table, empty types list
         (checkedStatements, finalSymtab, collectedTypes) = foldl processStatements ([], symtab, []) statements
 
-        -- Determine the block's type: unify all collected types, default to "Void" if none
+        -- Determine the block's type: unify all collected types, default to "void" if none (UpperBound)
         blockType = if null collectedTypes then "void" else foldl1 unifyReturnTypes collectedTypes
 
     in TypedStatement blockType (Block checkedStatements)
 
+
 typeCheckStatement (Return expr) symtab classes =
-  let expr' = case expr of
+  let methodReturnType = fromMaybe (error "Method return type not found in symbol table") (lookup "thisMeth" symtab)
+      expr' = case expr of
         Just e  -> Just (typeCheckExpression e symtab classes)
         Nothing -> Nothing
-   in case expr' of
-        Just e' -> TypedStatement (getTypeFromExpr e') (Return (Just e'))
-        Nothing -> TypedStatement "Void" (Return Nothing)
+      returnType = maybe "void" getTypeFromExpr expr'
+  in if returnType == methodReturnType || isSubtype returnType methodReturnType classes
+       then TypedStatement returnType (Return expr')
+       else error $ "Return: Return type mismatch: expected " ++ methodReturnType ++ ", found " ++ returnType
 
 typeCheckStatement (StatementExpressionStatement stmtExpr) symtab classes =
   let stmtExpr' = typeCheckStatementExpression stmtExpr symtab classes
@@ -310,6 +318,20 @@ typeCheckStatement (StatementExpressionStatement stmtExpr) symtab classes =
 
 -- ********************************** Type Checking: Helpers **********************************
 
+isSubtype :: DataType -> DataType -> [Class] -> Bool
+isSubtype subType superType classes
+  | subType == superType = True
+  | subType == "null" && isObjectType superType = True
+  | superType == "Object" && isObjectType subType = True
+  | superType == "Object" && isUserDefinedClass subType classes = True
+  | otherwise = False
+
+isUserDefinedClass :: DataType -> [Class] -> Bool
+isUserDefinedClass dt classes = dt `elem` map (\(Class name _ _) -> name) classes
+
+isObjectType :: DataType -> Bool
+isObjectType dt = dt /= "int" && dt /= "boolean" && dt /= "char"
+
 getTypeFromExpr :: Expression -> DataType
 getTypeFromExpr (TypedExpression t _) = t
 getTypeFromExpr _ = error "Untyped expression found where typed was expected"
@@ -325,10 +347,59 @@ getTypeFromStmtExpr _ = error "Untyped statement expression found where typed wa
 unifyReturnTypes :: DataType -> DataType -> DataType
 unifyReturnTypes dt1 dt2
   | dt1 == dt2 = dt1
+  | dt1 == "null" = dt2
+  | dt2 == "null" = dt1
   | otherwise = "Object"
 
-lookupType :: Identifier -> [(Identifier, DataType)] -> DataType
-lookupType id symtab =
-  case lookup id symtab of
-    Just t  -> t
-    Nothing -> error ("Identifier " ++ id ++ " not found in symbol table")
+resolveResultType :: DataType -> DataType -> DataType
+resolveResultType "char" "char" = "char"
+resolveResultType "int" "int" = "int"
+resolveResultType "char" "int" = "int"
+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 or char"
+
+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"