diff --git a/.gitignore b/.gitignore
index 94ff068..b46f74d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,8 @@
+# ingnore files without extension
+*
+!*.*
+!*/
+
 .DS_Store
 .vscode/settings.json
 
@@ -7,3 +12,4 @@ build/
 
 # brb build artifiacts
 *.o
+*.asm
\ No newline at end of file
diff --git a/.vscode/tasks.json b/.vscode/tasks.json
index 0fc81a3..99f9dd4 100644
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -3,12 +3,17 @@
     "tasks": [
         {
             "label": "Build Bits Runner Builder (Debug)",
-            "type": "cmake",
-            "command": "build",
+            "type": "shell",
+            "command": "cmake -B build && cmake --build build --config Debug",
             "group": {
                 "kind": "build",
                 "isDefault": true
             }
+        },
+        {
+            "label": "Clean",
+            "type": "shell",
+            "command": "rm -rf build *.o *.asm; find ./ -perm +100 -type f -maxdepth 1 -delete"
         }
     ]
 }
\ No newline at end of file
diff --git a/samples/fib.brc b/samples/fib.brc
index 11fd516..9835c85 100644
--- a/samples/fib.brc
+++ b/samples/fib.brc
@@ -1,6 +1,6 @@
-@extern putchar fun: character sint32 -> sint32
+@extern putchar fun: character u32 -> u32
 
-fib fun: number sint32 -> sint32
+fib fun: number u32 -> u32
     ret if number < 2:
         number
     else
@@ -8,13 +8,13 @@ fib fun: number sint32 -> sint32
     ;
 ;
 
-printNum fun: number sint32
-    biggest sint32 <- 10
+printNum fun: number u32
+    biggest u32 <- 10
     rep biggest <= number: biggest <- biggest * 10
     biggest <- biggest / 10
 
     rep biggest > 0:
-        digit sint32 <- number / biggest
+        digit u32 <- number / biggest
         putchar(digit + '0')
         number <- number % biggest
         biggest <- biggest / 10
@@ -22,9 +22,9 @@ printNum fun: number sint32
 ;
 
 // Print first 20 fibonaci numbers
-main fun -> sint32
-    rep i sint32 <- 0, i < 20:
-        res sint32 <- fib(i)
+main fun -> u32
+    rep i u32 <- 0, i < 20:
+        res u32 <- fib(i)
         printNum(res)
         putchar('\n')
         i <- i + 1
diff --git a/samples/hello.brc b/samples/hello.brc
index b8fa9d7..e93c560 100644
--- a/samples/hello.brc
+++ b/samples/hello.brc
@@ -1,9 +1,9 @@
-@extern putchar fun: character sint32 -> sint32
+@extern putchar fun: character u32 -> u32
 
-main fun -> sint32
-    text data<sint32> <- "Hello, world!\n"
+main fun -> u32
+    text data<u32> <- "Hello, world!\n"
     
-    rep i sint32 <- 0, text[i] != 0:
+    rep i u32 <- 0, text[i] != 0:
         putchar(text[i])
         i <- i + 1
     ;
diff --git a/samples/test.brc b/samples/test.brc
index 21321d7..baa3e8f 100644
--- a/samples/test.brc
+++ b/samples/test.brc
@@ -1,4 +1,4 @@
-@extern putchar fun: character sint32 -> sint32
+//@extern putchar fun: character sint32 -> sint32
 
 // ./build/brb samples/test.brc -S -x86-asm-syntax=intel
 
@@ -28,10 +28,10 @@ i u32 <- 0, rep text[i] != 0:
     ret num1 + num2
 ;*/
 
-rawAdd raw<"=r,r,r">: num1 sint32, num2 sint32 -> sint32
+/*rawAdd raw<"=r,r,r">: num1 sint32, num2 sint32 -> sint32
     add $1, $2
     mov $0, $1
-;
+;*/
 
 /*rawAdd raw: num1 sint32, num2 sint32 -> sint32
     add $1, $2
@@ -48,13 +48,14 @@ rawAdd raw<"=r,r,r">: num1 sint32, num2 sint32 -> sint32
 
 ;*/
 
-main fun -> sint32
-    /*a sint32 <- 4
-    b sint32 <- 5
+main fun -> u32
+    num1 u8 <- 42
+    num2 s8 <- 3 - +15
+    num3 u32 <- 1234123
+    num4 s32 <- -345345
+    num5 r32 <- -42.58
 
-    res sint32 <- rawAdd(4, 5)*/
-    putchar('@')
-    putchar('\n')
+    num5 + num3
 
     ret 0
 ;
\ No newline at end of file
diff --git a/src/Compiler/ModuleBuilder.cpp b/src/Compiler/ModuleBuilder.cpp
index 525652c..4fdd0d8 100644
--- a/src/Compiler/ModuleBuilder.cpp
+++ b/src/Compiler/ModuleBuilder.cpp
@@ -11,6 +11,7 @@
 #include "Parser/Expression/ExpressionCall.h"
 #include "Parser/Expression/ExpressionIfElse.h"
 #include "Parser/Expression/ExpressionBinary.h"
+#include "Parser/Expression/ExpressionUnary.h"
 #include "Parser/Expression/ExpressionBlock.h"
 
 #include "Parser/Statement/StatementFunction.h"
@@ -32,8 +33,11 @@ moduleName(moduleName), sourceFileName(sourceFileName), statements(statements) {
 
     typeVoid = llvm::Type::getVoidTy(*context);
     typeBool = llvm::Type::getInt1Ty(*context);
-    typeSint32 = llvm::Type::getInt32Ty(*context);
-    typeReal32 = llvm::Type::getFloatTy(*context);
+    typeU8 = llvm::Type::getInt8Ty(*context);
+    typeU32 = llvm::Type::getInt32Ty(*context);
+    typeS8 = llvm::Type::getInt8Ty(*context);
+    typeS32 = llvm::Type::getInt32Ty(*context);
+    typeR32 = llvm::Type::getFloatTy(*context);
 }
 
 shared_ptr<llvm::Module> ModuleBuilder::getModule() {
@@ -93,9 +97,15 @@ void ModuleBuilder::buildStatement(shared_ptr<Statement> statement) {
 void ModuleBuilder::buildFunction(shared_ptr<StatementFunction> statement) {
     // function types
     llvm::Type *returnType = typeForValueType(statement->getReturnValueType());
+    if (returnType == nullptr)
+        return;
     vector<llvm::Type *> argTypes;
-    for (pair<string, shared_ptr<ValueType>> &arg : statement->getArguments())
-        argTypes.push_back(typeForValueType(arg.second));
+    for (pair<string, shared_ptr<ValueType>> &arg : statement->getArguments()) {
+        llvm::Type *argType = typeForValueType(arg.second);
+        if (argType == nullptr)
+            return;
+        argTypes.push_back(argType);
+    }
 
     // build function declaration
     llvm::FunctionType *funType = llvm::FunctionType::get(returnType, argTypes, false);
@@ -169,6 +179,8 @@ void ModuleBuilder::buildVarDeclaration(shared_ptr<StatementVariable> statement)
         }
     } else {
         llvm::Value *value = valueForExpression(statement->getExpression());
+        if (value == nullptr)
+            return;
         llvm::AllocaInst *alloca = builder->CreateAlloca(typeForValueType(statement->getValueType(), 0), nullptr, statement->getName());
 
         if (!setAlloca(statement->getName(), alloca))
@@ -268,7 +280,10 @@ void ModuleBuilder::buildMetaExternFunction(shared_ptr<StatementMetaExternFuncti
     }
 
     // build function declaration
-    llvm::FunctionType *funType = llvm::FunctionType::get(typeForValueType(statement->getReturnValueType()), types, false);
+    llvm::Type *returnType = typeForValueType(statement->getReturnValueType());
+    if (returnType == nullptr)
+        return;
+    llvm::FunctionType *funType = llvm::FunctionType::get(returnType, types, false);
     llvm::Function *fun = llvm::Function::Create(funType, llvm::GlobalValue::ExternalLinkage, statement->getName(), module.get());
     if (!setFun(statement->getName(), fun))
         return;
@@ -294,6 +309,8 @@ llvm::Value *ModuleBuilder::valueForExpression(shared_ptr<Expression> expression
             return valueForExpression(dynamic_pointer_cast<ExpressionGrouping>(expression)->getExpression());
         case ExpressionKind::BINARY:
             return valueForBinary(dynamic_pointer_cast<ExpressionBinary>(expression));
+        case ExpressionKind::UNARY:
+            return valueForUnary(dynamic_pointer_cast<ExpressionUnary>(expression));
         case ExpressionKind::IF_ELSE:
             return valueForIfElse(dynamic_pointer_cast<ExpressionIfElse>(expression));
         case ExpressionKind::VAR:
@@ -325,10 +342,16 @@ llvm::Value *ModuleBuilder::valueForLiteral(shared_ptr<ExpressionLiteral> expres
             return llvm::UndefValue::get(typeVoid);
         case ValueTypeKind::BOOL:
             return llvm::ConstantInt::get(typeBool, expression->getBoolValue(), true);
-        case ValueTypeKind::SINT32:
-            return llvm::ConstantInt::get(typeSint32, expression->getSint32Value(), true);
-        case ValueTypeKind::REAL32:
-            return llvm::ConstantInt::get(typeReal32, expression->getReal32Value(), true);
+        case ValueTypeKind::U8:
+            return llvm::ConstantInt::get(typeU8, expression->getU8Value(), true);
+        case ValueTypeKind::U32:
+            return llvm::ConstantInt::get(typeU32, expression->getU32Value(), true);
+        case ValueTypeKind::S8:
+            return llvm::ConstantInt::get(typeS8, expression->getS8Value(), true);
+        case ValueTypeKind::S32:
+            return llvm::ConstantInt::get(typeS32, expression->getS32Value(), true);
+        case ValueTypeKind::R32:
+            return llvm::ConstantFP::get(typeR32, expression->getR32Value());
     }
 }
 
@@ -355,9 +378,11 @@ llvm::Value *ModuleBuilder::valueForBinary(shared_ptr<ExpressionBinary> expressi
 
     if (type == typeBool) {
         return valueForBinaryBool(expression->getOperation(), leftValue, rightValue);
-    } else if (type == typeSint32 || type == typeVoid) {
-        return valueForBinaryInteger(expression->getOperation(), leftValue, rightValue);
-    } else if (type == typeReal32) {
+    } else if (type == typeU8 || type == typeU32) {
+        return valueForBinaryUnsignedInteger(expression->getOperation(), leftValue, rightValue);
+    } else if (type == typeS8 || type == typeS32) {
+        return valueForBinarySignedInteger(expression->getOperation(), leftValue, rightValue);
+    } else if (type == typeR32) {
         return valueForBinaryReal(expression->getOperation(), leftValue, rightValue);
     }
 
@@ -372,35 +397,62 @@ llvm::Value *ModuleBuilder::valueForBinaryBool(ExpressionBinaryOperation operati
     case ExpressionBinaryOperation::NOT_EQUAL:
         return builder->CreateICmpNE(leftValue, rightValue);
     default:
-        markError(0, 0, "Unexpecgted operation for boolean operands");
+        markError(0, 0, "Unexpected operation for boolean operands");
         return nullptr;
     }
 }
 
-llvm::Value *ModuleBuilder::valueForBinaryInteger(ExpressionBinaryOperation operation, llvm::Value *leftValue, llvm::Value *rightValue) {
+llvm::Value *ModuleBuilder::valueForBinaryUnsignedInteger(ExpressionBinaryOperation operation, llvm::Value *leftValue, llvm::Value *rightValue) {
     switch (operation) {
-    case ExpressionBinaryOperation::EQUAL:
-        return builder->CreateICmpEQ(leftValue, rightValue);
-    case ExpressionBinaryOperation::NOT_EQUAL:
-        return builder->CreateICmpNE(leftValue, rightValue);
-    case ExpressionBinaryOperation::LESS:
-        return builder->CreateICmpSLT(leftValue, rightValue);
-    case ExpressionBinaryOperation::LESS_EQUAL:
-        return builder->CreateICmpSLE(leftValue, rightValue);
-    case ExpressionBinaryOperation::GREATER:
-        return builder->CreateICmpSGT(leftValue, rightValue);
-    case ExpressionBinaryOperation::GREATER_EQUAL:
-        return builder->CreateICmpSGE(leftValue, rightValue);
-    case ExpressionBinaryOperation::ADD:
-        return builder->CreateNSWAdd(leftValue, rightValue);
-    case ExpressionBinaryOperation::SUB:
-        return builder->CreateNSWSub(leftValue, rightValue);
-    case ExpressionBinaryOperation::MUL:
-        return builder->CreateNSWMul(leftValue, rightValue);
-    case ExpressionBinaryOperation::DIV:
-        return builder->CreateSDiv(leftValue, rightValue);
-    case ExpressionBinaryOperation::MOD:
-        return builder->CreateSRem(leftValue, rightValue);
+        case ExpressionBinaryOperation::EQUAL:
+            return builder->CreateICmpEQ(leftValue, rightValue);
+        case ExpressionBinaryOperation::NOT_EQUAL:
+            return builder->CreateICmpNE(leftValue, rightValue);
+        case ExpressionBinaryOperation::LESS:
+            return builder->CreateICmpSLT(leftValue, rightValue);
+        case ExpressionBinaryOperation::LESS_EQUAL:
+            return builder->CreateICmpSLE(leftValue, rightValue);
+        case ExpressionBinaryOperation::GREATER:
+            return builder->CreateICmpSGT(leftValue, rightValue);
+        case ExpressionBinaryOperation::GREATER_EQUAL:
+            return builder->CreateICmpSGE(leftValue, rightValue);
+        case ExpressionBinaryOperation::ADD:
+            return builder->CreateNUWAdd(leftValue, rightValue);
+        case ExpressionBinaryOperation::SUB:
+            return builder->CreateNUWSub(leftValue, rightValue);
+        case ExpressionBinaryOperation::MUL:
+            return builder->CreateNUWMul(leftValue, rightValue);
+        case ExpressionBinaryOperation::DIV:
+            return builder->CreateUDiv(leftValue, rightValue);
+        case ExpressionBinaryOperation::MOD:
+            return builder->CreateURem(leftValue, rightValue);
+    }
+}
+
+llvm::Value *ModuleBuilder::valueForBinarySignedInteger(ExpressionBinaryOperation operation, llvm::Value *leftValue, llvm::Value *rightValue) {
+    switch (operation) {
+        case ExpressionBinaryOperation::EQUAL:
+            return builder->CreateICmpEQ(leftValue, rightValue);
+        case ExpressionBinaryOperation::NOT_EQUAL:
+            return builder->CreateICmpNE(leftValue, rightValue);
+        case ExpressionBinaryOperation::LESS:
+            return builder->CreateICmpSLT(leftValue, rightValue);
+        case ExpressionBinaryOperation::LESS_EQUAL:
+            return builder->CreateICmpSLE(leftValue, rightValue);
+        case ExpressionBinaryOperation::GREATER:
+            return builder->CreateICmpSGT(leftValue, rightValue);
+        case ExpressionBinaryOperation::GREATER_EQUAL:
+            return builder->CreateICmpSGE(leftValue, rightValue);
+        case ExpressionBinaryOperation::ADD:
+            return builder->CreateNSWAdd(leftValue, rightValue);
+        case ExpressionBinaryOperation::SUB:
+            return builder->CreateNSWSub(leftValue, rightValue);
+        case ExpressionBinaryOperation::MUL:
+            return builder->CreateNSWMul(leftValue, rightValue);
+        case ExpressionBinaryOperation::DIV:
+            return builder->CreateSDiv(leftValue, rightValue);
+        case ExpressionBinaryOperation::MOD:
+            return builder->CreateSRem(leftValue, rightValue);
     }
 }
 
@@ -431,6 +483,26 @@ llvm::Value *ModuleBuilder::valueForBinaryReal(ExpressionBinaryOperation operati
     }
 }
 
+llvm::Value *ModuleBuilder::valueForUnary(shared_ptr<ExpressionUnary> expression) {
+    llvm::Value *value = valueForExpression(expression->getExpression());
+    llvm::Type *type = value->getType();
+
+    // do nothing for plus
+    if (expression->getOperation() == ExpressionUnaryOperation::PLUS)
+        return value;
+
+    if (type == typeU8 || type == typeU32) {
+        return builder->CreateNeg(value);
+    } else if (type == typeS8 || type == typeS32) {
+        return builder->CreateNSWNeg(value);
+    } else if (type == typeR32) {
+        return builder->CreateFNeg(value);
+    }
+
+    markError(0, 0, "Unexpected operation");
+    return nullptr;
+}
+
 llvm::Value *ModuleBuilder::valueForIfElse(shared_ptr<ExpressionIfElse> expression) {
     shared_ptr<Expression> conditionExpression = expression->getCondition();
 
@@ -600,22 +672,32 @@ llvm::InlineAsm *ModuleBuilder::getRawFun(string name) {
 }
 
 llvm::Type *ModuleBuilder::typeForValueType(shared_ptr<ValueType> valueType, int count) {
+    if (valueType == nullptr) {
+        markError(0, 0, "Missing type");
+        return nullptr;
+    }
+
     switch (valueType->getKind()) {
         case ValueTypeKind::NONE:
             return typeVoid;
         case ValueTypeKind::BOOL:
             return typeBool;
-        case ValueTypeKind::SINT32:
-            return typeSint32;
-        case ValueTypeKind::REAL32:
-            return typeReal32;
+        case ValueTypeKind::U8:
+            return typeU8;
+        case ValueTypeKind::U32:
+            return typeU32;
+        case ValueTypeKind::S8:
+            return typeS8;
+        case ValueTypeKind::S32:
+            return typeS32;
+        case ValueTypeKind::R32:
+            return typeR32;
         case ValueTypeKind::DATA: {
             if (valueType->getSubType() == nullptr)
                 return nullptr;
             if (valueType->getValueArg() > 0)
                 count = valueType->getValueArg();
             return llvm::ArrayType::get(typeForValueType(valueType->getSubType(), count), count);
-            return nullptr;
         }
     }
 }
diff --git a/src/Compiler/ModuleBuilder.h b/src/Compiler/ModuleBuilder.h
index 3378856..872b4ad 100644
--- a/src/Compiler/ModuleBuilder.h
+++ b/src/Compiler/ModuleBuilder.h
@@ -23,6 +23,7 @@ class ExpressionVariable;
 class ExpressionCall;
 class ExpressionIfElse;
 class ExpressionBinary;
+class ExpressionUnary;
 enum class ExpressionBinaryOperation;
 
 class Statement;
@@ -56,8 +57,11 @@ private:
 
     llvm::Type *typeVoid;
     llvm::Type *typeBool;
-    llvm::IntegerType *typeSint32;
-    llvm::Type *typeReal32;
+    llvm::IntegerType *typeU8;
+    llvm::IntegerType *typeU32;
+    llvm::IntegerType *typeS8;
+    llvm::IntegerType *typeS32;
+    llvm::Type *typeR32;
 
     vector<shared_ptr<Statement>> statements;
     stack<Scope> scopes;
@@ -80,8 +84,10 @@ private:
     llvm::Value *valueForGrouping(shared_ptr<ExpressionGrouping> expression);
     llvm::Value *valueForBinary(shared_ptr<ExpressionBinary> expression);
     llvm::Value *valueForBinaryBool(ExpressionBinaryOperation operation, llvm::Value *leftValue, llvm::Value *rightValue);
-    llvm::Value *valueForBinaryInteger(ExpressionBinaryOperation operation, llvm::Value *leftValue, llvm::Value *rightValue);
+    llvm::Value *valueForBinaryUnsignedInteger(ExpressionBinaryOperation operation, llvm::Value *leftValue, llvm::Value *rightValue);
+    llvm::Value *valueForBinarySignedInteger(ExpressionBinaryOperation operation, llvm::Value *leftValue, llvm::Value *rightValue);
     llvm::Value *valueForBinaryReal(ExpressionBinaryOperation operation, llvm::Value *leftValue, llvm::Value *rightValue);
+    llvm::Value *valueForUnary(shared_ptr<ExpressionUnary> expression);
     llvm::Value *valueForIfElse(shared_ptr<ExpressionIfElse> expression);
     llvm::Value *valueForVar(shared_ptr<ExpressionVariable> expression);
     llvm::Value *valueForCall(shared_ptr<ExpressionCall> expression);
diff --git a/src/Lexer/Token.cpp b/src/Lexer/Token.cpp
index 5fcc1df..2adddfe 100644
--- a/src/Lexer/Token.cpp
+++ b/src/Lexer/Token.cpp
@@ -4,21 +4,30 @@ vector<TokenKind> Token::tokensEquality = {
     TokenKind::EQUAL,
     TokenKind::NOT_EQUAL
 };
+
 vector<TokenKind> Token::tokensComparison = {
     TokenKind::LESS,
     TokenKind::LESS_EQUAL,
     TokenKind::GREATER,
     TokenKind::GREATER_EQUAL
 };
+
 vector<TokenKind> Token::tokensTerm = {
     TokenKind::PLUS,
     TokenKind::MINUS
 };
+
 vector<TokenKind> Token::tokensFactor = {
     TokenKind::STAR,
     TokenKind::SLASH,
     TokenKind::PERCENT
 };
+
+vector<TokenKind> Token::tokensUnary = {
+    TokenKind::PLUS,
+    TokenKind::MINUS
+};
+
 vector<TokenKind> Token::tokensBinary = {
     TokenKind::EQUAL,
     TokenKind::NOT_EQUAL,
@@ -35,6 +44,7 @@ vector<TokenKind> Token::tokensBinary = {
     TokenKind::SLASH,
     TokenKind::PERCENT
 };
+
 vector<TokenKind> Token::tokensLiteral = {
     TokenKind::BOOL,
     TokenKind::INTEGER_DEC,
diff --git a/src/Lexer/Token.h b/src/Lexer/Token.h
index c6ee86a..4b1ab57 100644
--- a/src/Lexer/Token.h
+++ b/src/Lexer/Token.h
@@ -65,6 +65,7 @@ public:
     static vector<TokenKind> tokensComparison;
     static vector<TokenKind> tokensTerm;
     static vector<TokenKind> tokensFactor;
+    static vector<TokenKind> tokensUnary;
     static vector<TokenKind> tokensBinary;
     static vector<TokenKind> tokensLiteral;
 
diff --git a/src/Logger.cpp b/src/Logger.cpp
index 98dd04e..d5ca83d 100644
--- a/src/Logger.cpp
+++ b/src/Logger.cpp
@@ -20,6 +20,7 @@
 
 #include "Parser/Expression/Expression.h"
 #include "Parser/Expression/ExpressionBinary.h"
+#include "Parser/Expression/ExpressionUnary.h"
 #include "Parser/Expression/ExpressionIfElse.h"
 #include "Parser/Expression/ExpressionVariable.h"
 #include "Parser/Expression/ExpressionGrouping.h"
@@ -202,15 +203,24 @@ string Logger::toString(TokenKind tokenKind) {
 }
 
 string Logger::toString(shared_ptr<ValueType> valueType) {
+    if (valueType == nullptr)
+        return "{INVALID}";
+
     switch (valueType->getKind()) {
         case ValueTypeKind::NONE:
             return "NONE";
         case ValueTypeKind::BOOL:
             return "BOOL";
-        case ValueTypeKind::SINT32:
-            return "SINT32";
-        case ValueTypeKind::REAL32:
-            return "REAL32";
+        case ValueTypeKind::U8:
+            return "U8";
+        case ValueTypeKind::U32:
+            return "U32";
+        case ValueTypeKind::S8:
+            return "S8";
+        case ValueTypeKind::S32:
+            return "S32";
+        case ValueTypeKind::R32:
+            return "R32";
         case ValueTypeKind::DATA:
             return "[]";
     }
@@ -338,7 +348,9 @@ string Logger::toString(shared_ptr<StatementExpression> statement) {
 string Logger::toString(shared_ptr<Expression> expression) {
     switch (expression->getKind()) {
         case ExpressionKind::BINARY:
-            return toString(dynamic_pointer_cast<ExpressionBinary>(expression));
+        return toString(dynamic_pointer_cast<ExpressionBinary>(expression));
+        case ExpressionKind::UNARY:
+            return toString(dynamic_pointer_cast<ExpressionUnary>(expression));
         case ExpressionKind::IF_ELSE:
             return toString(dynamic_pointer_cast<ExpressionIfElse>(expression));
         case ExpressionKind::VAR:
@@ -385,6 +397,17 @@ string Logger::toString(shared_ptr<ExpressionBinary> expression) {
     }
 }
 
+string Logger::toString(shared_ptr<ExpressionUnary> expression) {
+    switch (expression->getOperation()) {
+        case ExpressionUnaryOperation::PLUS:
+            return "+" + toString(expression->getExpression());
+        case ExpressionUnaryOperation::MINUS:
+            return "-" + toString(expression->getExpression());
+        case ExpressionUnaryOperation::INVALID:
+            return "{INVALID}";
+    }
+}
+
 string Logger::toString(shared_ptr<ExpressionIfElse> expression) {
     string text;
 
@@ -420,10 +443,16 @@ string Logger::toString(shared_ptr<ExpressionLiteral> expression) {
             return "NONE";
         case ValueTypeKind::BOOL:
             return expression->getBoolValue() ? "true" : "false";
-        case ValueTypeKind::SINT32:
-            return to_string(expression->getSint32Value());
-        case ValueTypeKind::REAL32:
-            return to_string(expression->getReal32Value());
+        case ValueTypeKind::U8:
+            return to_string(expression->getU8Value());
+        case ValueTypeKind::U32:
+            return to_string(expression->getU32Value());
+        case ValueTypeKind::S8:
+            return to_string(expression->getS8Value());
+        case ValueTypeKind::S32:
+            return to_string(expression->getS32Value());
+        case ValueTypeKind::R32:
+            return to_string(expression->getR32Value());
         default:
             return "?";
     }
diff --git a/src/Logger.h b/src/Logger.h
index 3101911..72e6746 100644
--- a/src/Logger.h
+++ b/src/Logger.h
@@ -20,6 +20,7 @@ class StatementExpression;
 
 class Expression;
 class ExpressionBinary;
+class ExpressionUnary;
 class ExpressionIfElse;
 class ExpressionVariable;
 class ExpressionGrouping;
@@ -51,6 +52,7 @@ private:
 
     static string toString(shared_ptr<Expression> expression);
     static string toString(shared_ptr<ExpressionBinary> expression);
+    static string toString(shared_ptr<ExpressionUnary> expression);
     static string toString(shared_ptr<ExpressionIfElse> expression);
     static string toString(shared_ptr<ExpressionVariable> expression);
     static string toString(shared_ptr<ExpressionGrouping> expression);
diff --git a/src/Parser/Expression/Expression.h b/src/Parser/Expression/Expression.h
index 66bd170..a335052 100644
--- a/src/Parser/Expression/Expression.h
+++ b/src/Parser/Expression/Expression.h
@@ -12,6 +12,7 @@ enum class ExpressionKind {
     LITERAL,
     ARRAY_LITERAL,
     GROUPING,
+    UNARY,
     BINARY,
     IF_ELSE,
     VAR,
diff --git a/src/Parser/Expression/ExpressionBinary.h b/src/Parser/Expression/ExpressionBinary.h
index 0c5bb4c..56b31fa 100644
--- a/src/Parser/Expression/ExpressionBinary.h
+++ b/src/Parser/Expression/ExpressionBinary.h
@@ -1,4 +1,7 @@
-#include "Parser/Expression/Expression.h"
+#ifndef EXPRESSION_BINARY_H
+#define EXPRESSION_BINARY_H
+
+#include "Expression.h"
 
 enum class ExpressionBinaryOperation {
     EQUAL,
@@ -26,4 +29,6 @@ public:
     ExpressionBinaryOperation getOperation();
     shared_ptr<Expression> getLeft();
     shared_ptr<Expression> getRight();
-};
\ No newline at end of file
+};
+
+#endif
\ No newline at end of file
diff --git a/src/Parser/Expression/ExpressionLiteral.cpp b/src/Parser/Expression/ExpressionLiteral.cpp
index 648046e..4675d40 100644
--- a/src/Parser/Expression/ExpressionLiteral.cpp
+++ b/src/Parser/Expression/ExpressionLiteral.cpp
@@ -15,14 +15,14 @@ shared_ptr<ExpressionLiteral> ExpressionLiteral::expressionLiteralForToken(share
         case TokenKind::INTEGER_DEC: {
             string numString = token->getLexme();
             erase(numString, '_');
-            expression->sint32Value = stoi(numString, nullptr, 10);
+            expression->s32Value = stoi(numString, nullptr, 10);
             expression->valueType = ValueType::valueTypeForToken(token, nullptr, 0);
             break;
         }
         case TokenKind::INTEGER_HEX: {
             string numString = token->getLexme();
             erase(numString, '_');
-            expression->sint32Value = stoi(numString, nullptr, 16);
+            expression->u32Value = stoul(numString, nullptr, 16);
             expression->valueType = ValueType::valueTypeForToken(token, nullptr, 0);
             break;
         }
@@ -30,7 +30,7 @@ shared_ptr<ExpressionLiteral> ExpressionLiteral::expressionLiteralForToken(share
             string numString = token->getLexme();
             erase(numString, '_');
             numString = numString.substr(2, numString.size()-1);
-            expression->sint32Value = stoi(numString, nullptr, 2);
+            expression->u32Value = stoul(numString, nullptr, 2);
             expression->valueType = ValueType::valueTypeForToken(token, nullptr, 0);
             break;
         }
@@ -41,13 +41,14 @@ shared_ptr<ExpressionLiteral> ExpressionLiteral::expressionLiteralForToken(share
                 return nullptr;
             
             expression->valueType = ValueType::valueTypeForToken(token, nullptr, 0);
-            expression->sint32Value = *charValue;
+            expression->u32Value = *charValue;
             return expression;
         }
-        case TokenKind::REAL:
-            expression->real32Value = stof(token->getLexme());
+        case TokenKind::REAL: {
+            expression->r32Value = stof(token->getLexme());
             expression->valueType = ValueType::valueTypeForToken(token, nullptr, 0);
             break;
+        }
         default:
             return nullptr;
     }
@@ -62,10 +63,22 @@ bool ExpressionLiteral::getBoolValue() {
     return boolValue;
 }
 
-int32_t ExpressionLiteral::getSint32Value() {
-    return sint32Value;
+uint8_t ExpressionLiteral::getU8Value() {
+    return u8Value;
 }
 
-float ExpressionLiteral::getReal32Value() {
-    return real32Value;
+uint32_t ExpressionLiteral::getU32Value() {
+    return u32Value;
+}
+
+int8_t ExpressionLiteral::getS8Value() {
+    return s8Value;
+}
+
+int32_t ExpressionLiteral::getS32Value() {
+    return s32Value;
+}
+
+float ExpressionLiteral::getR32Value() {
+    return r32Value;
 }
diff --git a/src/Parser/Expression/ExpressionLiteral.h b/src/Parser/Expression/ExpressionLiteral.h
index 89b545e..89b8bf4 100644
--- a/src/Parser/Expression/ExpressionLiteral.h
+++ b/src/Parser/Expression/ExpressionLiteral.h
@@ -6,16 +6,22 @@
 class ExpressionLiteral: public Expression {
 private:
     bool boolValue;
-    int32_t sint32Value;
-    float real32Value;
+    uint8_t u8Value;
+    uint32_t u32Value;
+    int8_t s8Value;
+    int32_t s32Value;
+    float r32Value;
 
 public:
     static shared_ptr<ExpressionLiteral> expressionLiteralForToken(shared_ptr<Token> token);
     
     ExpressionLiteral();
     bool getBoolValue();
-    int32_t getSint32Value();
-    float getReal32Value();
+    uint8_t getU8Value();
+    uint32_t getU32Value();
+    int8_t getS8Value();
+    int32_t getS32Value();
+    float getR32Value();
 };
 
 #endif
\ No newline at end of file
diff --git a/src/Parser/Expression/ExpressionUnary.cpp b/src/Parser/Expression/ExpressionUnary.cpp
new file mode 100644
index 0000000..ddc570d
--- /dev/null
+++ b/src/Parser/Expression/ExpressionUnary.cpp
@@ -0,0 +1,29 @@
+#include "ExpressionUnary.h"
+
+#include "Lexer/Token.h"
+
+ExpressionUnary::ExpressionUnary(shared_ptr<Token> token, shared_ptr<Expression> expression):
+Expression(ExpressionKind::UNARY, nullptr), expression(expression) {
+    switch (token->getKind()) {
+        case TokenKind::PLUS:
+            operation = ExpressionUnaryOperation::PLUS;
+            valueType = expression->getValueType();
+            break;
+        case TokenKind::MINUS:
+            operation = ExpressionUnaryOperation::MINUS;
+            valueType = expression->getValueType();
+            break;
+        default:
+            operation = ExpressionUnaryOperation::INVALID;
+            valueType = nullptr;
+            break;
+    }
+}
+
+ExpressionUnaryOperation ExpressionUnary::getOperation() {
+    return operation;
+}
+
+shared_ptr<Expression> ExpressionUnary::getExpression() {
+    return expression;
+}
\ No newline at end of file
diff --git a/src/Parser/Expression/ExpressionUnary.h b/src/Parser/Expression/ExpressionUnary.h
new file mode 100644
index 0000000..2ba56fd
--- /dev/null
+++ b/src/Parser/Expression/ExpressionUnary.h
@@ -0,0 +1,23 @@
+#ifndef EXPRESSION_UNARY_H
+#define EXPRESSION_UNARY_H
+
+#include "Expression.h"
+
+enum class ExpressionUnaryOperation {
+    PLUS,
+    MINUS,
+    INVALID
+};
+
+class ExpressionUnary: public Expression {
+private:
+    ExpressionUnaryOperation operation;
+    shared_ptr<Expression> expression;
+
+public:
+    ExpressionUnary(shared_ptr<Token> token, shared_ptr<Expression> expression);
+    ExpressionUnaryOperation getOperation();
+    shared_ptr<Expression> getExpression();
+};
+
+#endif
\ No newline at end of file
diff --git a/src/Parser/Parser.cpp b/src/Parser/Parser.cpp
index 0db1a3d..bdf291f 100644
--- a/src/Parser/Parser.cpp
+++ b/src/Parser/Parser.cpp
@@ -12,6 +12,7 @@
 #include "Parser/Expression/ExpressionVariable.h"
 #include "Parser/Expression/ExpressionCall.h"
 #include "Parser/Expression/ExpressionIfElse.h"
+#include "Parser/Expression/ExpressionUnary.h"
 #include "Parser/Expression/ExpressionBinary.h"
 #include "Parser/Expression/ExpressionBlock.h"
 
@@ -723,7 +724,7 @@ shared_ptr<Expression> Parser::matchTerm() {
 }
 
 shared_ptr<Expression> Parser::matchFactor() {
-    shared_ptr<Expression> expression = matchPrimary();
+    shared_ptr<Expression> expression = matchUnary();
     if (expression == nullptr)
         return nullptr;
 
@@ -733,6 +734,19 @@ shared_ptr<Expression> Parser::matchFactor() {
     return expression;
 }
 
+shared_ptr<Expression> Parser::matchUnary() {
+    shared_ptr<Token> token = tokens.at(currentIndex);
+
+    if (tryMatchingTokenKinds(Token::tokensUnary, false, true)) {
+        shared_ptr<Expression> expression = matchPrimary();
+        if (expression == nullptr)
+            return nullptr;
+        return make_shared<ExpressionUnary>(token, expression);
+    }
+
+    return matchPrimary();
+}
+
 shared_ptr<Expression> Parser::matchPrimary() {
     shared_ptr<Expression> expression;
     int errorsCount = errors.size();
@@ -742,8 +756,8 @@ shared_ptr<Expression> Parser::matchPrimary() {
         return expression;
 
     expression = matchExpressionArrayLiteral();
-        if (expression != nullptr || errors.size() > errorsCount)
-            return expression;
+    if (expression != nullptr || errors.size() > errorsCount)
+        return expression;
 
     expression = matchExpressionLiteral();
     if (expression != nullptr || errors.size() > errorsCount)
@@ -1052,7 +1066,7 @@ optional<ParseeResult> Parser::valueTypeParseeResult(int index) {
             int storedIndex = currentIndex;
             currentIndex = index;
             shared_ptr<Expression> expressionValue = matchExpressionLiteral();
-            typeArg = dynamic_pointer_cast<ExpressionLiteral>(expressionValue)->getSint32Value();
+            typeArg = dynamic_pointer_cast<ExpressionLiteral>(expressionValue)->getU32Value();
             currentIndex = storedIndex;
             index++;
         }
diff --git a/src/Parser/Parser.h b/src/Parser/Parser.h
index 8e5a8d5..0e27960 100644
--- a/src/Parser/Parser.h
+++ b/src/Parser/Parser.h
@@ -43,7 +43,8 @@ private:
     shared_ptr<Expression> matchComparison(); // <, <=, >, >=
     shared_ptr<Expression> matchTerm(); // +, -
     shared_ptr<Expression> matchFactor(); // *, /, %
-    shared_ptr<Expression> matchPrimary(); // integer, ()
+    shared_ptr<Expression> matchUnary(); // +, -
+    shared_ptr<Expression> matchPrimary(); // literal, ()
 
     shared_ptr<Expression> matchExpressionGrouping();
     shared_ptr<Expression> matchExpressionLiteral();
diff --git a/src/Parser/ValueType.cpp b/src/Parser/ValueType.cpp
index 6f5945d..566342b 100644
--- a/src/Parser/ValueType.cpp
+++ b/src/Parser/ValueType.cpp
@@ -4,8 +4,11 @@
 
 shared_ptr<ValueType> ValueType::NONE = make_shared<ValueType>(ValueTypeKind::NONE, nullptr, 0);
 shared_ptr<ValueType> ValueType::BOOL = make_shared<ValueType>(ValueTypeKind::BOOL, nullptr, 0);
-shared_ptr<ValueType> ValueType::SINT32 = make_shared<ValueType>(ValueTypeKind::SINT32, nullptr, 0);
-shared_ptr<ValueType> ValueType::REAL32 = make_shared<ValueType>(ValueTypeKind::REAL32, nullptr, 0);
+shared_ptr<ValueType> ValueType::U8 = make_shared<ValueType>(ValueTypeKind::U8, nullptr, 0);
+shared_ptr<ValueType> ValueType::U32 = make_shared<ValueType>(ValueTypeKind::U32, nullptr, 0);
+shared_ptr<ValueType> ValueType::S8 = make_shared<ValueType>(ValueTypeKind::S8, nullptr, 0);
+shared_ptr<ValueType> ValueType::S32 = make_shared<ValueType>(ValueTypeKind::S32, nullptr, 0);
+shared_ptr<ValueType> ValueType::R32 = make_shared<ValueType>(ValueTypeKind::R32, nullptr, 0);
 
 ValueType::ValueType(ValueTypeKind kind, shared_ptr<ValueType> subType, int valueArg):
 kind(kind), subType(subType), valueArg(valueArg) { }
@@ -16,10 +19,16 @@ shared_ptr<ValueType> ValueType::valueTypeForToken(shared_ptr<Token> token, shar
             string lexme = token->getLexme();
             if (lexme.compare("bool") == 0)
                 return make_shared<ValueType>(ValueTypeKind::BOOL, subType, valueArg);
-            else if (lexme.compare("sint32") == 0)
-                return make_shared<ValueType>(ValueTypeKind::SINT32, subType, valueArg);
-            else if (lexme.compare("real32") == 0)
-                return make_shared<ValueType>(ValueTypeKind::REAL32, subType, valueArg);
+            else if (lexme.compare("u8") == 0)
+                return make_shared<ValueType>(ValueTypeKind::U8, subType, valueArg);
+            else if (lexme.compare("u32") == 0)
+                return make_shared<ValueType>(ValueTypeKind::U32, subType, valueArg);
+            else if (lexme.compare("s8") == 0)
+                return make_shared<ValueType>(ValueTypeKind::S8, subType, valueArg);
+            else if (lexme.compare("s32") == 0)
+                return make_shared<ValueType>(ValueTypeKind::S32, subType, valueArg);
+            else if (lexme.compare("r32") == 0)
+                return make_shared<ValueType>(ValueTypeKind::R32, subType, valueArg);
             else if (lexme.compare("data") == 0)
                 return make_shared<ValueType>(ValueTypeKind::DATA, subType, valueArg);
             else
@@ -28,12 +37,13 @@ shared_ptr<ValueType> ValueType::valueTypeForToken(shared_ptr<Token> token, shar
         case TokenKind::BOOL:
             return make_shared<ValueType>(ValueTypeKind::BOOL, nullptr, 0);
         case TokenKind::INTEGER_DEC:
+            return make_shared<ValueType>(ValueTypeKind::S32, nullptr, 0);
         case TokenKind::INTEGER_HEX:
         case TokenKind::INTEGER_BIN:
         case TokenKind::INTEGER_CHAR:
-            return make_shared<ValueType>(ValueTypeKind::SINT32, nullptr, 0);
+            return make_shared<ValueType>(ValueTypeKind::U32, nullptr, 0);
         case TokenKind::REAL:
-            return make_shared<ValueType>(ValueTypeKind::REAL32, nullptr, 0);
+            return make_shared<ValueType>(ValueTypeKind::R32, nullptr, 0);
         default:
             return nullptr;
     }
diff --git a/src/Parser/ValueType.h b/src/Parser/ValueType.h
index ce118eb..2b77f2f 100644
--- a/src/Parser/ValueType.h
+++ b/src/Parser/ValueType.h
@@ -10,8 +10,11 @@ using namespace std;
 enum class ValueTypeKind {
     NONE,
     BOOL,
-    SINT32,
-    REAL32,
+    U8,
+    U32,
+    S8,
+    S32,
+    R32,
     DATA
 };
 
@@ -24,8 +27,11 @@ private:
 public:
     static shared_ptr<ValueType> NONE;
     static shared_ptr<ValueType> BOOL;
-    static shared_ptr<ValueType> SINT32;
-    static shared_ptr<ValueType> REAL32;
+    static shared_ptr<ValueType> U8;
+    static shared_ptr<ValueType> U32;
+    static shared_ptr<ValueType> S8;
+    static shared_ptr<ValueType> S32;
+    static shared_ptr<ValueType> R32;
     static shared_ptr<ValueType> valueTypeForToken(shared_ptr<Token> token, shared_ptr<ValueType> subType, int valueArg);
 
     ValueType(ValueTypeKind kind, shared_ptr<ValueType> subType, int valueArg);