diff --git a/.run/spice.run.xml b/.run/spice.run.xml
index d59378dae..c69468147 100644
--- a/.run/spice.run.xml
+++ b/.run/spice.run.xml
@@ -1,5 +1,5 @@
 <component name="ProjectRunConfigurationManager">
-  <configuration default="false" name="spice" type="CMakeRunConfiguration" factoryName="Application" PROGRAM_PARAMS="run -O2 -ir ../../media/test-project/test.spice" REDIRECT_INPUT="false" ELEVATE="false" USE_EXTERNAL_CONSOLE="false" EMULATE_TERMINAL="false" PASS_PARENT_ENVS_2="true" PROJECT_NAME="Spice" TARGET_NAME="spice" CONFIG_NAME="Debug" RUN_TARGET_PROJECT_NAME="Spice" RUN_TARGET_NAME="spice">
+  <configuration default="false" name="spice" type="CMakeRunConfiguration" factoryName="Application" PROGRAM_PARAMS="run -O0 -d -ir ../../media/test-project/test.spice" REDIRECT_INPUT="false" ELEVATE="false" USE_EXTERNAL_CONSOLE="false" EMULATE_TERMINAL="false" PASS_PARENT_ENVS_2="true" PROJECT_NAME="Spice" TARGET_NAME="spice" CONFIG_NAME="Debug" RUN_TARGET_PROJECT_NAME="Spice" RUN_TARGET_NAME="spice">
     <envs>
       <env name="LLVM_LIB_DIR" value="D:/LLVM/build-release/lib" />
       <env name="LLVM_INCLUDE_DIR" value="D:/LLVM/llvm/include" />
diff --git a/media/test-project/test.spice b/media/test-project/test.spice
index 890dfe14c..50c34f9b7 100644
--- a/media/test-project/test.spice
+++ b/media/test-project/test.spice
@@ -1,57 +1,5 @@
-import "std/data/vector";
-import "../../src-bootstrap/bindings/llvm/llvm" as llvm;
+import "../../src-bootstrap/reader/reader";
 
 f<int> main() {
-    //llvm::initializeAllTargets();
-    //llvm::initializeAllTargetInfos();
-    //llvm::initializeAllTargetMCs();
-    //llvm::initializeAllAsmPrinters();
-    llvm::initializeNativeTarget();
-    llvm::initializeNativeAsmPrinter();
-
-    heap string targetTriple = llvm::getDefaultTargetTriple();
-    string error;
-    llvm::Target target = llvm::getTargetFromTriple(targetTriple, &error);
-    llvm::TargetMachine targetMachine = target.createTargetMachine(targetTriple, "generic", "", llvm::LLVMCodeGenOptLevel::CodeGenLevelDefault, llvm::LLVMRelocMode::RelocDefault, llvm::LLVMCodeModel::CodeModelDefault);
-
-    llvm::LLVMContext context;
-    llvm::Module module = llvm::Module("test", context);
-    module.setDataLayout(targetMachine.createDataLayout());
-    module.setTargetTriple(targetTriple);
-    llvm::Builder builder = llvm::Builder(context);
-
-    llvm::Type returnType = builder.getInt32Ty();
-    Vector<llvm::Type> argTypes;
-    llvm::Type funcType = llvm::getFunctionType(returnType, argTypes);
-    llvm::Function func = llvm::Function(module, "main", funcType);
-    func.setLinkage(llvm::LLVMLinkage::ExternalLinkage);
-
-    llvm::BasicBlock entry = llvm::BasicBlock(context, "");
-    func.pushBack(entry);
-    builder.setInsertPoint(entry);
-
-    llvm::Value calcResult = builder.createAdd(builder.getInt32(1), builder.getInt32(2), "calcResult");
-
-    llvm::Value helloWorldStr = builder.createGlobalStringPtr("Hello, world!\n", "helloWorldStr");
-    Vector<llvm::Type> printfArgTypes;
-    printfArgTypes.pushBack(builder.getPtrTy());
-    printfArgTypes.pushBack(builder.getInt32Ty());
-    llvm::Type printfFuncType = llvm::getFunctionType(builder.getInt32Ty(), printfArgTypes, true);
-    llvm::Function printfFunc = module.getOrInsertFunction("printf", printfFuncType);
-
-    Vector<llvm::Value> printfArgs;
-    printfArgs.pushBack(helloWorldStr);
-    printfArgs.pushBack(calcResult);
-    builder.createCall(printfFunc, printfArgs);
-
-    builder.createRet(builder.getInt32(0));
-
-    assert !llvm::verifyFunction(func);
-    string output;
-    assert !llvm::verifyModule(module, &output);
-
-    printf("%s", module.print());
-
-    llvm::PassBuilderOptions passBuilderOptions;
-    //llvm::PassBuilder passBuilder = llvm::PassBuilder(module, passBuilderOptions);
+    Reader reader = Reader("./test.spice");
 }
\ No newline at end of file
diff --git a/media/test-project/test2.spice b/media/test-project/test2.spice
index 7d1cd3a0d..253aa716e 100644
--- a/media/test-project/test2.spice
+++ b/media/test-project/test2.spice
@@ -1,9 +1,16 @@
-public type Driveable interface {
-    public p drive(int);
-    public f<bool> isDriving();
+import "std/type/result";
+import "std/type/error";
+
+type FilePtr alias byte*;
+public type File struct {
+    FilePtr* filePtr
 }
 
-#[test]
-f<bool> testDriveable() {
-    return true;
+// Link external functions
+ext f<FilePtr*> fopen(string, string);
+
+public f<Result<File>> openFile(string path, string mode) {
+    FilePtr* fp = fopen(path, mode);
+    File file = File{fp};
+    return fp != nil<FilePtr*> ? ok(file) : err(file, Error("Failed to open file"));
 }
\ No newline at end of file
diff --git a/src-bootstrap/ast/AbstractASTVisitor.spice b/src-bootstrap/ast/abstract-ast-visitor.spice
similarity index 93%
rename from src-bootstrap/ast/AbstractASTVisitor.spice
rename to src-bootstrap/ast/abstract-ast-visitor.spice
index 46adbb37d..9541f7901 100644
--- a/src-bootstrap/ast/AbstractASTVisitor.spice
+++ b/src-bootstrap/ast/abstract-ast-visitor.spice
@@ -1,3 +1,4 @@
+// Std imports
 import "std/type/any";
 
 public type IAbstractAstVisitor interface {
diff --git a/src-bootstrap/ast/ASTBuilder.spice b/src-bootstrap/ast/ast-builder.spice
similarity index 81%
rename from src-bootstrap/ast/ASTBuilder.spice
rename to src-bootstrap/ast/ast-builder.spice
index e72e03060..7134a2339 100644
--- a/src-bootstrap/ast/ASTBuilder.spice
+++ b/src-bootstrap/ast/ast-builder.spice
@@ -1,6 +1,6 @@
-import "../CompilerPass";
-import "../SourceFile";
-import "SpiceVisitor";
+import "../compiler-pass";
+import "../source-file";
+import "../ast/spice-visitor";
 
 type ASTBuilder struct : ICompilerPass, SpiceVisitor {
     CompilerPass compilerPass
diff --git a/src-bootstrap/ast/ASTNodes.spice b/src-bootstrap/ast/ast-nodes.spice
similarity index 99%
rename from src-bootstrap/ast/ASTNodes.spice
rename to src-bootstrap/ast/ast-nodes.spice
index e3ff36f55..6d4b5c36d 100644
--- a/src-bootstrap/ast/ASTNodes.spice
+++ b/src-bootstrap/ast/ast-nodes.spice
@@ -3,9 +3,9 @@ import "std/type/Any";
 import "std/data/Vector";
 
 // Own imports
-import "AbstractASTVisitor";
-import "../util/CodeLoc";
-import "../symbol/SymbolType";
+import "../ast/abstract-ast-visitor";
+import "../reader/code-loc";
+import "../symbol/symbol-type";
 
 /**
  * Saves a constant value for an AST node to realize features like array-out-of-bounds checks
diff --git a/src-bootstrap/bindings/llvm/llvm.spice b/src-bootstrap/bindings/llvm/llvm.spice
index 45bc5da42..0e4ade0b3 100644
--- a/src-bootstrap/bindings/llvm/llvm.spice
+++ b/src-bootstrap/bindings/llvm/llvm.spice
@@ -1,7 +1,10 @@
+#![core.compiler.warnings.ignore]
+
+// Std imports
 import "std/data/vector";
-import "linker-flags";
 
-#![core.compiler.warnings.ignore]
+// Own imports
+import "linker-flags";
 
 // ===== External type definitions =====
 type VoidPtr alias byte*;
diff --git a/src-bootstrap/CompilerPass.spice b/src-bootstrap/compiler-pass.spice
similarity index 91%
rename from src-bootstrap/CompilerPass.spice
rename to src-bootstrap/compiler-pass.spice
index 3cbc82aa6..305cb6c11 100644
--- a/src-bootstrap/CompilerPass.spice
+++ b/src-bootstrap/compiler-pass.spice
@@ -1,4 +1,4 @@
-import "global/GlobalResourceManager";
+import "./global/global-resource-manager";
 
 type ICompilerPass interface {
     p changeToScope(Scope*, const ScopeType&);
diff --git a/src-bootstrap/CliInterface.spice b/src-bootstrap/driver.spice
similarity index 94%
rename from src-bootstrap/CliInterface.spice
rename to src-bootstrap/driver.spice
index 997305b38..88cb3675b 100644
--- a/src-bootstrap/CliInterface.spice
+++ b/src-bootstrap/driver.spice
@@ -1,4 +1,4 @@
-// Imports
+// Std imports
 import "std/text/print";
 import "std/os/cmd";
 import "std/io/cli-parser";
@@ -37,7 +37,7 @@ public type CliOptions struct {
 /**
  * Helper class to setup the cli interface and command line parser
  */
-public type CliInterface struct {
+public type Driver struct {
     CliParser cliParser
     public CliOptions cliOptions
     public bool shouldCompile = false
@@ -45,12 +45,12 @@ public type CliInterface struct {
     public bool shouldExecute = false
 }
 
-public p CliInterface.create() {
+public p Driver.create() {
     this.cliParser = CliParser("Spice", "Spice programming language");
     this.cliParser.setFooter("(c) Marc Auberer 2021-2023");
 
     // Add version flag
-    this.cliParser.setVersion("Spice version 0.14.3\nbuilt by: GitHub Actions\n\n(c) Marc Auberer 2021-2023");
+    this.cliParser.setVersion("Spice version 0.18.3\nbuilt by: GitHub Actions\n\n(c) Marc Auberer 2021-2023");
 
     // Create sub-commands
     this.addBuildSubcommand();
@@ -64,7 +64,7 @@ public p CliInterface.create() {
 /**
  * Initialize the cli options based on the input of the user
  */
-public p CliInterface.enrich() {
+public p Driver.enrich() {
     // Propagate target information
     if this.cliOptions.targetTriple.isEmpty() && this.cliOptions.targetArch.isEmpty() {
         // ToDo: Extend
@@ -81,7 +81,7 @@ public p CliInterface.enrich() {
 /**
  * Add build subcommand to cli interface
  */
-p CliInterface.addBuildSubcommand() {
+p Driver.addBuildSubcommand() {
     // Create sub-command itself
     CliSubcommand& subCmd = this.cliParser.createSubcommand("build", "Builds your Spice program and emits an executable");
     subCmd.addAlias("b");
@@ -112,7 +112,7 @@ p CliInterface.addBuildSubcommand() {
 /**
  * Add run subcommand to cli interface
  */
-p CliInterface.addRunSubcommand() {
+p Driver.addRunSubcommand() {
     // Create sub-command itself
     CliSubcommand& subCmd = this.cliParser.createSubcommand("run", "Builds your Spice program and runs it immediately");
     subCmd.addAlias("r");
@@ -132,7 +132,7 @@ p CliInterface.addRunSubcommand() {
 /**
  * Add install subcommand to cli interface
  */
-p CliInterface.addInstallSubcommand() {
+p Driver.addInstallSubcommand() {
     // Create sub-command itself
     CliSubcommand& subCmd = this.cliParser.createSubcommand("install", "Builds your Spice program and installs it to a directory in the PATH variable");
     subCmd.addAlias("i");
@@ -143,7 +143,7 @@ p CliInterface.addInstallSubcommand() {
 /**
  * Add uninstall subcommand to cli interface
  */
-p CliInterface.addUninstallSubcommand() {
+p Driver.addUninstallSubcommand() {
     // Create sub-command itself
     CliSubcommand& subCmd = this.cliParser.createSubcommand("uninstall", "Builds your Spice program and runs it immediately");
     subCmd.addAlias("u");
@@ -151,7 +151,7 @@ p CliInterface.addUninstallSubcommand() {
     addCompileSubcommandOptions(subCmd);
 }
 
-p CliInterface.addCompileSubcommandOptions(CliSubcommand& subCmd) {
+p Driver.addCompileSubcommandOptions(CliSubcommand& subCmd) {
     // --debug-output
     CliOption<bool>& debugOutputFlag = subCmd.addFlag("--debug-output", this.cliOptions.printDebugOutput, "Enable debug output");
     debugOutputFlag.addAlias("-d");
@@ -200,6 +200,6 @@ p CliInterface.addCompileSubcommandOptions(CliSubcommand& subCmd) {
  * @param argv Argument vector
  * @return Return code
  */
-public f<int> CliInterface.parse(int argc, string[] argv) {
+public f<int> Driver.parse(int argc, string[] argv) {
     return this.cliParser.parse(argc, argv);
 }
\ No newline at end of file
diff --git a/src-bootstrap/exception/IRError.spice b/src-bootstrap/exception/IRError.spice
deleted file mode 100644
index cb1e9b3b4..000000000
--- a/src-bootstrap/exception/IRError.spice
+++ /dev/null
@@ -1,56 +0,0 @@
-// Imports
-import "../util/CodeLoc" as cl;
-
-public type IRErrorType enum {
-    TARGET_NOT_AVAILABLE,
-    CANT_OPEN_OUTPUT_FILE,
-    WRONG_OUTPUT_TYPE,
-    BRANCH_NOT_FOUND,
-    REFERENCED_UNDEFINED_FUNCTION_IR,
-    PRINTF_NULL_TYPE,
-    INVALID_FUNCTION,
-    INVALID_MODULE,
-    COMING_SOON_IR
-}
-
-/**
- * Custom exception for errors, occurring in the code generation phase
- */
-public type IRError struct {
-    string errorMessage
-}
-
-/**
- * @param errorType Type of the error
- * @param message Error message suffix
- */
-public p IRError.ctor(const CodeLoc* codeLoc, const IRErrorType errorType, const string message) {
-    this.errorMessage = "[Error|Linker] " + this.getMessagePrefix(errorType) + ": " + message;
-}
-
-/**
- * @param errorType Type of the error
- * @param message Error message suffix
- */
-public p IRError.ctor(const IRErrorType errorType, const string message) {
-    this.errorMessage = "[Error|Linker] " + this.getMessagePrefix(errorType) + ": " + message;
-}
-
-/**
- * Get the prefix of the error message for a particular error
- *
- * @param errorType Type of the error
- * @return Prefix string for the error type
- */
-f<string> IRError.getMessagePrefix(const IRErrorType errorType) {
-    if errorType == LinkerErrorType.TARGET_NOT_AVAILABLE { return "Selected target not available"; }
-    if errorType == LinkerErrorType.CANT_OPEN_OUTPUT_FILE { return "Could not open output file"; }
-    if errorType == LinkerErrorType.WRONG_OUTPUT_TYPE { return "Wrong type of output file"; }
-    if errorType == LinkerErrorType.BRANCH_NOT_FOUND { return "Branch not found"; }
-    if errorType == LinkerErrorType.REFERENCED_UNDEFINED_FUNCTION_IR { return "Referenced undefined function"; }
-    if errorType == LinkerErrorType.PRINTF_NULL_TYPE { return "Printf has null type"; }
-    if errorType == LinkerErrorType.INVALID_FUNCTION { return "Invalid function"; }
-    if errorType == LinkerErrorType.INVALID_MODULE { return "Invalid module"; }
-    if errorType == LinkerErrorType.COMING_SOON_IR { return "Coming soon"; }
-    return "Unknown error";
-}
\ No newline at end of file
diff --git a/src-bootstrap/exception/CliError.spice b/src-bootstrap/exception/cli-error.spice
similarity index 96%
rename from src-bootstrap/exception/CliError.spice
rename to src-bootstrap/exception/cli-error.spice
index b76b37d93..bcf174f76 100644
--- a/src-bootstrap/exception/CliError.spice
+++ b/src-bootstrap/exception/cli-error.spice
@@ -1,5 +1,5 @@
-// Imports
-import "../util/CodeLoc" as cl;
+// Own imports
+import "../reader/code-loc";
 
 public type CliErrorType enum {
     INCOMPLETE_TARGET_TRIPLE,
diff --git a/src-bootstrap/exception/LexerError.spice b/src-bootstrap/exception/lexer-error.spice
similarity index 86%
rename from src-bootstrap/exception/LexerError.spice
rename to src-bootstrap/exception/lexer-error.spice
index c725135c8..8e54970f3 100644
--- a/src-bootstrap/exception/LexerError.spice
+++ b/src-bootstrap/exception/lexer-error.spice
@@ -1,5 +1,5 @@
 // Imports
-import "../util/CodeLoc" as cl;
+import "../util/code-loc";
 
 public type LexerErrorType enum {
     TOKENIZING_FAILED
@@ -19,7 +19,7 @@ public type ParserError struct {
  * @param errorType Type of the error
  * @param message Error message suffix
  */
-public p ParserError.ctor(const cl::CodeLoc* codeLoc, const LexerErrorType errorType, const string message) {
+public p ParserError.ctor(const CodeLoc* codeLoc, const LexerErrorType errorType, const string message) {
     this.errorMessage = "[Error|Lexer] " + codeLoc.toPrettyString() + ": " + this.getMessagePrefix(errorType) + ": " + message;
 }
 
diff --git a/src-bootstrap/exception/LinkerError.spice b/src-bootstrap/exception/linker-error.spice
similarity index 96%
rename from src-bootstrap/exception/LinkerError.spice
rename to src-bootstrap/exception/linker-error.spice
index bd3adcc27..bd8492c1e 100644
--- a/src-bootstrap/exception/LinkerError.spice
+++ b/src-bootstrap/exception/linker-error.spice
@@ -1,5 +1,5 @@
 // Imports
-import "../util/CodeLoc" as cl;
+import "../util/code-loc";
 
 public type LinkerErrorType enum {
     LINKER_NOT_FOUND,
diff --git a/src-bootstrap/exception/ParserError.spice b/src-bootstrap/exception/parser-error.spice
similarity index 88%
rename from src-bootstrap/exception/ParserError.spice
rename to src-bootstrap/exception/parser-error.spice
index 0e699943a..cee5504c7 100644
--- a/src-bootstrap/exception/ParserError.spice
+++ b/src-bootstrap/exception/parser-error.spice
@@ -1,5 +1,5 @@
 // Imports
-import "../util/CodeLoc" as cl;
+import "../util/code-loc";
 
 public type ParserErrorType enum {
     PARSING_FAILED,
@@ -21,7 +21,7 @@ public type ParserError struct {
  * @param errorType Type of the error
  * @param message Error message suffix
  */
-public p ParserError.ctor(const cl::CodeLoc* codeLoc, const ParserErrorType errorType, const string message) {
+public p ParserError.ctor(const CodeLoc* codeLoc, const ParserErrorType errorType, const string message) {
     this.errorMessage = "[Error|Parser] " + codeLoc.toPrettyString() + ": " + this.getMessagePrefix(errorType) + ": " + message;
 }
 
diff --git a/src-bootstrap/exception/SemanticError.spice b/src-bootstrap/exception/semantic-error.spice
similarity index 94%
rename from src-bootstrap/exception/SemanticError.spice
rename to src-bootstrap/exception/semantic-error.spice
index 864729381..1161f4571 100644
--- a/src-bootstrap/exception/SemanticError.spice
+++ b/src-bootstrap/exception/semantic-error.spice
@@ -1,6 +1,6 @@
-// Imports
-import "../ast/AstNodes" as ast;
-import "../util/CodeLoc" as cl;
+// Own imports
+import "../ast/ast-nodes";
+import "../reader/code-loc";
 
 public type SemanticErrorType enum {
     REFERENCED_UNDEFINED_FUNCTION,
@@ -74,7 +74,7 @@ public type SemanticError struct {
     string message
 }
 
-public p SemanticError.ctor(const ast::AstNode* node, const SemanticErrorType errorType, const string message) {
+public p SemanticError.ctor(const AstNode* node, const SemanticErrorType errorType, const string message) {
     this.errorMessage = "[Error|Semantic] " + node.codeLoc.toPrettyString() + ":\n" + this.getMessagePrefix(errorType) +
             ": " + message + "\n\n" + node.errorMessage;
 }
diff --git a/src-bootstrap/global/GlobalResourceManager.spice b/src-bootstrap/global/global-resource-manager.spice
similarity index 89%
rename from src-bootstrap/global/GlobalResourceManager.spice
rename to src-bootstrap/global/global-resource-manager.spice
index e7deaa6f4..8db172a9d 100644
--- a/src-bootstrap/global/GlobalResourceManager.spice
+++ b/src-bootstrap/global/global-resource-manager.spice
@@ -1,9 +1,9 @@
-import "../exception/ErrorManager";
-import "../global/RuntimeModuleManager";
-import "../linker/ExternalLinkerInterface";
-import "../util/CodeLoc";
-import "../util/Timer";
-import "../CliInterface";
+// Own imports
+import "../global/runtime-module-manager";
+import "../linker/external-linker-interface";
+import "../reader/code-loc";
+import "../util/timer";
+import "../driver";
 
 // Constants
 public const string MAIN_FILE_NAME = "root";
diff --git a/src-bootstrap/generator/generator.spice b/src-bootstrap/irgenerator/ir-generator.spice
similarity index 52%
rename from src-bootstrap/generator/generator.spice
rename to src-bootstrap/irgenerator/ir-generator.spice
index bbe2c37b5..3642ece81 100644
--- a/src-bootstrap/generator/generator.spice
+++ b/src-bootstrap/irgenerator/ir-generator.spice
@@ -1,4 +1,6 @@
-// Imports
+// Std imports
+
+// Own imports
 
 public type Generator struct {
 
diff --git a/src-bootstrap/lexer/Lexer.spice b/src-bootstrap/lexer/Lexer.spice
deleted file mode 100644
index 6f47bcf28..000000000
--- a/src-bootstrap/lexer/Lexer.spice
+++ /dev/null
@@ -1,2 +0,0 @@
-// Imports
-import "Token" as tk;
\ No newline at end of file
diff --git a/src-bootstrap/lexer/Reader.spice b/src-bootstrap/lexer/Reader.spice
deleted file mode 100644
index 38280a8e6..000000000
--- a/src-bootstrap/lexer/Reader.spice
+++ /dev/null
@@ -1,40 +0,0 @@
-// Imports
-import "std/io/file" as file;
-
-public type Reader struct {
-    File inputFile
-    char curChar
-    char nextChar
-    bool metEof
-    unsigned long line
-    unsigned long col
-}
-
-public p Reader.ctor(const string inputFileName) {
-    this.inputFile = file.openFile(inputFileName, file::MODE_READ);
-    this.cursorPos = 0;
-    this.metEof = false;
-    this.line = 1;
-    this.col = 0;
-    // Fill
-}
-
-public f<char> Reader.getCurChar() {
-    return this.curChar;
-}
-
-public f<bool> Reader.expectChar(char expected) {
-    bool gotExpected = expected == this.nextChar;
-    this.advance();
-    return gotExpected;
-}
-
-public p Reader.advance() {
-    int readChar = this.inputFile.readChar();
-    if readChar == -1 {
-        metEof = true;
-        return;
-    }
-    this.curChar = this.nextChar;
-    this.nextChar = (char) readChar;
-}
\ No newline at end of file
diff --git a/src-bootstrap/lexer/lexer.spice b/src-bootstrap/lexer/lexer.spice
new file mode 100644
index 000000000..cb3b2eb20
--- /dev/null
+++ b/src-bootstrap/lexer/lexer.spice
@@ -0,0 +1,2 @@
+// Imports
+import "../lexer/token";
\ No newline at end of file
diff --git a/src-bootstrap/lexer/Token.spice b/src-bootstrap/lexer/token.spice
similarity index 98%
rename from src-bootstrap/lexer/Token.spice
rename to src-bootstrap/lexer/token.spice
index 97f6e6188..09512db55 100644
--- a/src-bootstrap/lexer/Token.spice
+++ b/src-bootstrap/lexer/token.spice
@@ -1,5 +1,5 @@
 // Imports
-import "../util/CodeLoc";
+import "../reader/code-loc";
 
 // Enums
 public type TokenType enum {
diff --git a/src-bootstrap/main.spice b/src-bootstrap/main.spice
index c2cfc3126..de06b4de8 100644
--- a/src-bootstrap/main.spice
+++ b/src-bootstrap/main.spice
@@ -1,8 +1,10 @@
+// Std imports
 import "std/os/os";
 
-import "SourceFile";
-import "CliInterface";
-import "global/GlobalResourceManager";
+// Own imports
+import "./source-file";
+import "./driver";
+import "./global/global-resource-manager";
 
 /**
  * Compile main source file. All files, that are included by the main source file will be resolved recursively.
@@ -44,28 +46,28 @@ f<bool> compileProject(const CliOptions& cliOptions) {
  */
 f<int> main(int argc, string[] argv) {
     // Initialize command line parser
-    CliInterface cli;
-    cli.create();
-    const int exitCode = cli.parse(argc, argv);
+    Driver driver;
+    driver.create();
+    const int exitCode = driver.parse(argc, argv);
     if exitCode != EXIT_SUCCESS {
         return exitCode;
     }
 
     // Cancel here if we do not have to compile
-    if !cli.shouldCompile {
+    if !driver.shouldCompile {
         return EXIT_SUCCESS;
     }
 
-    cli.enrich(); // Prepare the cli options
+    driver.enrich(); // Prepare the cli options
 
     // Kick off the compiling process
-    if !compileProject(cli.cliOptions) {
+    if !compileProject(driver.cliOptions) {
         return EXIT_FAILURE;
     }
 
     // Execute
-    if cli.cliOptions.execute {
-        cli.runBinary();
+    if driver.cliOptions.execute {
+        driver.runBinary();
     }
 
     return EXIT_SUCCESS;
diff --git a/src-bootstrap/model/Function.spice b/src-bootstrap/model/function.spice
similarity index 97%
rename from src-bootstrap/model/Function.spice
rename to src-bootstrap/model/function.spice
index af37683ac..d93b6da14 100644
--- a/src-bootstrap/model/Function.spice
+++ b/src-bootstrap/model/function.spice
@@ -1,3 +1,4 @@
+// Std imports
 import "std/data/vector";
 import "std/data/map";
 
diff --git a/src-bootstrap/parser/Parser.spice b/src-bootstrap/parser/parser.spice
similarity index 76%
rename from src-bootstrap/parser/Parser.spice
rename to src-bootstrap/parser/parser.spice
index cf6a92ac4..edb9bb0fe 100644
--- a/src-bootstrap/parser/Parser.spice
+++ b/src-bootstrap/parser/parser.spice
@@ -1,5 +1,5 @@
-// Imports
-import "../lexer/Token" as tk;
+// Own imports
+import "../lexer/token";
 
 public type Parser struct {
 
diff --git a/src-bootstrap/util/CodeLoc.spice b/src-bootstrap/reader/code-loc.spice
similarity index 81%
rename from src-bootstrap/util/CodeLoc.spice
rename to src-bootstrap/reader/code-loc.spice
index ff772767f..0645e470f 100644
--- a/src-bootstrap/util/CodeLoc.spice
+++ b/src-bootstrap/reader/code-loc.spice
@@ -28,9 +28,9 @@ public f<String> CodeLoc.toString() {
  * @return Pretty code location
  */
 public f<String> CodeLoc.toPrettyString() {
-    String codeLocStr = String(intTy.toString(this.line));
-    if this.sourceFilePath.empty() {
-        return toString(line) + ":" + toString(this.col);
+    String codeLocStr = String(toString(this.line));
+    if len(this.sourceFilePath) == 0 {
+        return toString(this.line) + ":" + toString(this.col);
     }
     return this.sourceFilePath + ":" + toString(this.line) + ":" + toString(this.col);
 }
@@ -52,5 +52,5 @@ public f<String> CodeLoc.toPrettyLineAndColumn() {
 }
 
 public f<bool> operator==(const CodeLoc &lhs, const CodeLoc &rhs) {
-    return /*lhs.sourceFilePath == rhs.sourceFilePath && */lhs.line == rhs.line && lhs.col == rhs.col;
+    return lhs.sourceFilePath == rhs.sourceFilePath && lhs.line == rhs.line && lhs.col == rhs.col;
 }
\ No newline at end of file
diff --git a/src-bootstrap/reader/reader.spice b/src-bootstrap/reader/reader.spice
new file mode 100644
index 000000000..db7c40a67
--- /dev/null
+++ b/src-bootstrap/reader/reader.spice
@@ -0,0 +1,80 @@
+// Std imports
+import "std/io/filepath";
+import "std/io/file";
+import "std/type/result";
+import "std/type/error";
+
+// Own import
+import "../reader/code-loc";
+
+public type Reader struct {
+    File file
+    string filename
+    char curChar = '\0'
+    unsigned long line = 1l
+    unsigned long col = 0l
+}
+
+public p Reader.ctor(const string inputFileName) {
+    this.filename = inputFileName;
+    Result<File> result = openFile(inputFileName, MODE_READ);
+    if !result.isOk() {
+        panic(Error("Source file cannot be opened"));
+    }
+    this.file = result.unwrap();
+}
+
+public p Reader.dtor() {
+    this.file.close();
+}
+
+/**
+ * @brief Get the previously read character
+ *
+ * @return char Last character
+ */
+public f<char> Reader.getChar() {
+    return this.curChar;
+}
+
+/**
+ * @brief Get the code location of the previously read character
+ *
+ * @return CodeLoc Code location
+ */
+public f<CodeLoc> Reader.getCodeLoc() {
+    return CodeLoc(this.line, this.col, this.filename);
+}
+
+/**
+ * @brief Advance the reader by one character
+ */
+public p Reader.advance() {
+    assert !this.isEOF();
+    this.curChar = (char) this.file.readChar();
+    if this.curChar == '\n' {
+        this.line++;
+        this.col = 0l;
+    }
+    this.col++;
+}
+
+/**
+ * @brief Advance the reader by one character and check if this char equals the
+ * expected
+ *
+ * @param c Expected char
+ */
+public p Reader.expect(char c) {
+    assert this.curChar == c;
+    this.advance();
+}
+
+/**
+ * @brief Check if we are at the end of the input file
+ *
+ * @return At the end or not
+ */
+public f<bool> Reader.isEOF() {
+    return this.file.isEOF();
+}
\ No newline at end of file
diff --git a/src-bootstrap/SourceFile.spice b/src-bootstrap/source-file.spice
similarity index 97%
rename from src-bootstrap/SourceFile.spice
rename to src-bootstrap/source-file.spice
index 974027ac2..790b9fece 100644
--- a/src-bootstrap/SourceFile.spice
+++ b/src-bootstrap/source-file.spice
@@ -1,9 +1,9 @@
 // Imports
 import "std/text/print";
 import "std/data/pair";
-import "CliInterface";
-import "global/GlobalResourceManager";
-import "ast/AstNodes";
+import "./driver";
+import "./global/global-resource-manager";
+import "./ast/ast-nodes";
 
 type CompileStageType enum {
     NONE,
diff --git a/src-bootstrap/symbol/Scope.spice b/src-bootstrap/symboltablebuilder/scope.spice
similarity index 99%
rename from src-bootstrap/symbol/Scope.spice
rename to src-bootstrap/symboltablebuilder/scope.spice
index 08581027f..9903ab3eb 100644
--- a/src-bootstrap/symbol/Scope.spice
+++ b/src-bootstrap/symboltablebuilder/scope.spice
@@ -1,5 +1,7 @@
+// Std imports
 import "std/data/map";
 
+// Own imports
 
 type ScopeType enum {
     GLOBAL,
diff --git a/src-bootstrap/symbol/SymbolTableEntry.spice b/src-bootstrap/symboltablebuilder/symbol-table-entry.spice
similarity index 100%
rename from src-bootstrap/symbol/SymbolTableEntry.spice
rename to src-bootstrap/symboltablebuilder/symbol-table-entry.spice
diff --git a/src-bootstrap/symbol/SymbolTable.spice b/src-bootstrap/symboltablebuilder/symbol-table.spice
similarity index 98%
rename from src-bootstrap/symbol/SymbolTable.spice
rename to src-bootstrap/symboltablebuilder/symbol-table.spice
index e35f2343f..ee39839ed 100644
--- a/src-bootstrap/symbol/SymbolTable.spice
+++ b/src-bootstrap/symboltablebuilder/symbol-table.spice
@@ -3,14 +3,14 @@ import "std/data/map";
 import "std/data/vector";
 
 // Own imports
-import "../ast/AstNodes";
-import "SymbolType";
-import "SymbolTableEntry";
-import "TypeSpecifiers";
-import "Capture";
-import "GenericType";
-import "Function";
-import "Interface";
+import "../ast/ast-nodes";
+import "../symboltablebuilder/symbol-type";
+import "../symboltablebuilder/symbol-table-entry";
+import "../symboltablebuilder/type-specifiers";
+import "../model/capture";
+import "../model/generic-type";
+import "../model/function";
+import "../model/interface";
 
 public type ScopeType enum {
     GLOBAL,
diff --git a/src-bootstrap/symbol/SymbolType.spice b/src-bootstrap/symboltablebuilder/symbol-type.spice
similarity index 97%
rename from src-bootstrap/symbol/SymbolType.spice
rename to src-bootstrap/symboltablebuilder/symbol-type.spice
index a61ad3f9e..7ead7e287 100644
--- a/src-bootstrap/symbol/SymbolType.spice
+++ b/src-bootstrap/symboltablebuilder/symbol-type.spice
@@ -1,7 +1,9 @@
 // Std imports
 import "std/data/vector";
-import "../util/CommonUtil";
-import "../symbol/Scope";
+
+// Own imports
+import "../util/common-util";
+import "../symbol/scope";
 
 public type SymbolSuperType enum {
     TY_INVALID,
diff --git a/src-bootstrap/util/CommonUtil.spice b/src-bootstrap/util/common-util.spice
similarity index 100%
rename from src-bootstrap/util/CommonUtil.spice
rename to src-bootstrap/util/common-util.spice
diff --git a/src-bootstrap/util/CompilerWarning.spice b/src-bootstrap/util/compiler-warning.spice
similarity index 93%
rename from src-bootstrap/util/CompilerWarning.spice
rename to src-bootstrap/util/compiler-warning.spice
index 156174b67..e0845d538 100644
--- a/src-bootstrap/util/CompilerWarning.spice
+++ b/src-bootstrap/util/compiler-warning.spice
@@ -1,5 +1,5 @@
 // Own imports
-import "CodeLoc" as cl;
+import "../reader/code-loc";
 
 public type CompilerWarningType enum {
     UNUSED_FUNCTION,
@@ -31,7 +31,7 @@ public type CompilerWarning struct {
  * @param warningType Type of the warning
  * @param message Warning message suffix
  */
-public p CompilerWarning.ctor(const cl::CodeLoc* codeLoc, const CompilerWarningType warningType, const string message) {
+public p CompilerWarning.ctor(const CodeLoc* codeLoc, const CompilerWarningType warningType, const string message) {
     this.warningMessage = "[Warning] " + codeLoc.toPrettyString() + ": " +
             this.getMessagePrefix(warningType) + ": " + message;
 }
@@ -77,7 +77,7 @@ f<string> CompilerWarning.getMessagePrefix(const CompilerWarningType warningType
 }
 
 f<int> main() {
-    const cl::CodeLoc codeLoc = cl::CodeLoc(2l, 3l);
+    const CodeLoc codeLoc = CodeLoc(2l, 3l);
     CompilerWarning warning = CompilerWarning(&codeLoc, CompilerWarningType.UNUSED_STRUCT, "Dies ist ein Test");
     warning.print();
 }
\ No newline at end of file
diff --git a/src-bootstrap/util/FileUtil.spice b/src-bootstrap/util/file-util.spice
similarity index 100%
rename from src-bootstrap/util/FileUtil.spice
rename to src-bootstrap/util/file-util.spice
diff --git a/src/SourceFile.cpp b/src/SourceFile.cpp
index f21e19f9b..8eabf56b2 100644
--- a/src/SourceFile.cpp
+++ b/src/SourceFile.cpp
@@ -54,6 +54,7 @@ void SourceFile::runLexer() {
   // Create error handlers for lexer and parser
   antlrCtx.lexerErrorHandler = std::make_unique<AntlrThrowingErrorListener>(ThrowingErrorListenerMode::LEXER, filePath);
   antlrCtx.parserErrorHandler = std::make_unique<AntlrThrowingErrorListener>(ThrowingErrorListenerMode::PARSER, filePath);
+  std::ifstream test;
 
   // Tokenize input
   antlrCtx.inputStream = std::make_unique<antlr4::ANTLRInputStream>(fileInputStream);
diff --git a/src/Spice.g4 b/src/Spice.g4
index ccf090577..f3d8e5696 100644
--- a/src/Spice.g4
+++ b/src/Spice.g4
@@ -12,7 +12,7 @@ structDef: topLevelDefAttr? specifierLst? TYPE TYPE_IDENTIFIER (LESS typeLst GRE
 interfaceDef: specifierLst? TYPE TYPE_IDENTIFIER (LESS typeLst GREATER)? INTERFACE LBRACE signature+ RBRACE;
 enumDef: specifierLst? TYPE TYPE_IDENTIFIER ENUM LBRACE enumItemLst RBRACE;
 genericTypeDef: TYPE TYPE_IDENTIFIER typeAltsLst SEMICOLON;
-aliasDef: TYPE TYPE_IDENTIFIER ALIAS dataType SEMICOLON;
+aliasDef: specifierLst? TYPE TYPE_IDENTIFIER ALIAS dataType SEMICOLON;
 globalVarDef: dataType TYPE_IDENTIFIER (ASSIGN constant)? SEMICOLON;
 extDecl: topLevelDefAttr? EXT (F LESS dataType GREATER | P) (IDENTIFIER | TYPE_IDENTIFIER) LPAREN (typeLst ELLIPSIS?)? RPAREN SEMICOLON;
 
diff --git a/src/ast/ASTNodes.h b/src/ast/ASTNodes.h
index b9172eefe..bffe0da51 100644
--- a/src/ast/ASTNodes.h
+++ b/src/ast/ASTNodes.h
@@ -161,6 +161,7 @@ class ASTNode {
   [[nodiscard]] virtual bool isFctOrProcDef() const { return false; }
   [[nodiscard]] virtual bool isStructDef() const { return false; }
   [[nodiscard]] virtual bool isStmtNode() const { return false; }
+  [[nodiscard]] virtual bool isParamNode() const { return false; }
   [[nodiscard]] virtual bool isAssignExpr() const { return false; }
 
   // Public members
@@ -446,12 +447,14 @@ class AliasDefNode : public ASTNode {
   std::any accept(ParallelizableASTVisitor *visitor) const override { return visitor->visitAliasDef(this); }
 
   // Public get methods
+  [[nodiscard]] SpecifierLstNode *specifierLst() const { return getChild<SpecifierLstNode>(); }
   [[nodiscard]] DataTypeNode *dataType() const { return getChild<DataTypeNode>(); }
 
   // Public members
   std::string aliasName;
   std::string dataTypeString;
   SymbolTableEntry *entry = nullptr;
+  TypeSpecifiers aliasSpecifiers = TypeSpecifiers::of(TY_ALIAS);
   SymbolTableEntry *aliasedTypeContainerEntry = nullptr;
 };
 
@@ -916,6 +919,7 @@ class DeclStmtNode : public ASTNode {
 
   // Util methods
   void customItemsInitialization(size_t manifestationCount) override { entries.resize(manifestationCount, nullptr); }
+  [[nodiscard]] bool isParamNode() const override { return isParam; }
 
   // Public members
   std::string varName;
diff --git a/src/global/GlobalResourceManager.cpp b/src/global/GlobalResourceManager.cpp
index 3a9a29c65..1e3561247 100644
--- a/src/global/GlobalResourceManager.cpp
+++ b/src/global/GlobalResourceManager.cpp
@@ -57,6 +57,11 @@ GlobalResourceManager::GlobalResourceManager(const CliOptions &cliOptions)
     ltoModule = std::make_unique<llvm::Module>(LTO_FILE_NAME, context);
 }
 
+GlobalResourceManager::~GlobalResourceManager() {
+  // Cleanup all global LLVM resources
+  llvm::llvm_shutdown();
+}
+
 SourceFile *GlobalResourceManager::createSourceFile(SourceFile *parent, const std::string &dependencyName,
                                                     const std::filesystem::path &path, bool isStdFile) {
   // Check if the source file was already added (e.g. by another source file that imports it)
diff --git a/src/global/GlobalResourceManager.h b/src/global/GlobalResourceManager.h
index c4ba33c12..375c2f1f8 100644
--- a/src/global/GlobalResourceManager.h
+++ b/src/global/GlobalResourceManager.h
@@ -36,6 +36,7 @@ class GlobalResourceManager {
   // Constructors
   explicit GlobalResourceManager(const CliOptions &cliOptions);
   GlobalResourceManager(const GlobalResourceManager &) = delete;
+  ~GlobalResourceManager();
 
   // Public methods
   SourceFile *createSourceFile(SourceFile *parent, const std::string &dependencyName, const std::filesystem::path &path,
diff --git a/src/irgenerator/DebugInfoGenerator.cpp b/src/irgenerator/DebugInfoGenerator.cpp
index 4b65edc99..3f7a09a0b 100644
--- a/src/irgenerator/DebugInfoGenerator.cpp
+++ b/src/irgenerator/DebugInfoGenerator.cpp
@@ -325,7 +325,7 @@ llvm::DIType *DebugInfoGenerator::getDITypeForSymbolType(const ASTNode *node, co
     llvm::Type *structType = spiceStruct->entry->getType().toLLVMType(irGenerator->context, irGenerator->currentScope);
     assert(structType != nullptr);
     const llvm::StructLayout *structLayout =
-        irGenerator->module->getDataLayout().getStructLayout(static_cast<llvm::StructType *>(structType));
+        irGenerator->module->getDataLayout().getStructLayout(reinterpret_cast<llvm::StructType *>(structType));
     const uint32_t alignInBits = irGenerator->module->getDataLayout().getABITypeAlign(structType).value();
 
     // Create struct type
diff --git a/src/irgenerator/GenImplicit.cpp b/src/irgenerator/GenImplicit.cpp
index 97f13e7b5..0354844ea 100644
--- a/src/irgenerator/GenImplicit.cpp
+++ b/src/irgenerator/GenImplicit.cpp
@@ -103,9 +103,14 @@ void IRGenerator::generateCtorOrDtorCall(SymbolTableEntry *entry, const Function
 }
 
 void IRGenerator::generateDeallocCall(llvm::Value *variableAddress) const {
-  // Issue call
-  llvm::Function *deallocFct = stdFunctionManager.getDeallocBytePtrRefFct();
-  builder.CreateCall(deallocFct, variableAddress);
+  // In case of string runtime, call free manually. Otherwise, use the memory_rt implementation of sDealloc()
+  if (sourceFile->isStringRT()) {
+    llvm::Function *freeFct = stdFunctionManager.getFreeFctPtr();
+    builder.CreateCall(freeFct, variableAddress);
+  } else {
+    llvm::Function *deallocFct = stdFunctionManager.getDeallocBytePtrRefFct();
+    builder.CreateCall(deallocFct, variableAddress);
+  }
 }
 
 llvm::Function *IRGenerator::generateImplicitFunction(const std::function<void(void)> &generateBody, const Function *spiceFunc) {
diff --git a/src/irgenerator/GenTopLevelDefinitions.cpp b/src/irgenerator/GenTopLevelDefinitions.cpp
index 6596de247..712cea12f 100644
--- a/src/irgenerator/GenTopLevelDefinitions.cpp
+++ b/src/irgenerator/GenTopLevelDefinitions.cpp
@@ -479,45 +479,9 @@ std::any IRGenerator::visitStructDef(const StructDefNode *node) {
     currentScope = spiceStruct->scope;
     assert(currentScope);
 
-    // Create struct definition
-    const std::string mangledName = NameMangling::mangleStruct(*spiceStruct);
-    llvm::StructType *structType = llvm::StructType::create(context, mangledName);
-
     // Set LLVM type to the struct entry
     SymbolTableEntry *structEntry = spiceStruct->entry;
     assert(structEntry != nullptr);
-    structEntry->setStructLLVMType(structType);
-    std::vector<llvm::Type *> fieldTypes;
-    fieldTypes.reserve(node->fields().size());
-
-    // Collect interface types
-    if (const TypeLstNode *typeLst = node->interfaceTypeLst()) {
-      for (const DataTypeNode *interfaceTypeNode : typeLst->dataTypes()) {
-        const SymbolType symbolType = interfaceTypeNode->getEvaluatedSymbolType(manIdx);
-        assert(symbolType.is(TY_INTERFACE));
-        const Interface *interface = symbolType.getInterface(interfaceTypeNode);
-        assert(interface != nullptr);
-        llvm::StructType *interfaceType = interface->entry->getStructLLVMType();
-        assert(interfaceType != nullptr);
-        fieldTypes.push_back(interfaceType);
-      }
-    } else if (node->emitVTable) {
-      // If no interface was specified, we still need to add a pointer to the VTable
-      fieldTypes.push_back(builder.getPtrTy());
-    }
-
-    // Collect concrete field types
-    for (const FieldNode *field : node->fields()) {
-      SymbolTableEntry *fieldEntry = currentScope->lookupStrict(field->fieldName);
-      assert(fieldEntry && !fieldEntry->getType().hasAnyGenericParts());
-      fieldTypes.push_back(fieldEntry->getType().toLLVMType(context, currentScope));
-    }
-
-    // Set field types to struct type
-    bool isPacked = false;
-    if (node->attrs() && node->attrs()->attrLst()->hasAttr(ATTR_CORE_COMPILER_PACKED))
-      isPacked = node->attrs()->attrLst()->getAttrValueByName(ATTR_CORE_COMPILER_PACKED)->boolValue;
-    structType->setBody(fieldTypes, isPacked);
 
     // Generate VTable if required
     if (node->emitVTable) {
@@ -567,15 +531,6 @@ std::any IRGenerator::visitInterfaceDef(const InterfaceDefNode *node) {
     if (!spiceInterface->used && !spiceInterface->entry->getType().isPublic())
       continue;
 
-    // Generate empty struct
-    const std::string mangledName = NameMangling::mangleInterface(*spiceInterface);
-    llvm::StructType *structType = llvm::StructType::create(context, mangledName);
-    structType->setBody(builder.getPtrTy());
-
-    // Set LLVM type to the interface entry
-    node->entry->setStructLLVMType(structType);
-    spiceInterface->entry->setStructLLVMType(structType);
-
     // Generate VTable information
     generateVTable(spiceInterface);
     deferredVTableInitializations.emplace_back([=, this]() { generateVTableInitializer(spiceInterface); }, false);
diff --git a/src/irgenerator/GenVTable.cpp b/src/irgenerator/GenVTable.cpp
index 68997081e..b47c8530e 100644
--- a/src/irgenerator/GenVTable.cpp
+++ b/src/irgenerator/GenVTable.cpp
@@ -35,7 +35,7 @@ llvm::Constant *IRGenerator::generateTypeInfo(StructBase *spiceStruct) {
 
   std::vector<SymbolType> interfaceTypes;
   if (spiceStruct->entry->getType().is(TY_STRUCT)) {
-    auto spiceStructEnsured = static_cast<Struct *>(spiceStruct);
+    auto spiceStructEnsured = reinterpret_cast<Struct *>(spiceStruct);
     interfaceTypes = spiceStructEnsured->interfaceTypes;
   }
 
@@ -121,7 +121,7 @@ void IRGenerator::generateVTableInitializer(StructBase *spiceStruct) {
   // Generate VTable type
   llvm::PointerType *ptrTy = llvm::PointerType::get(context, 0);
   llvm::ArrayType *vtableArrayTy = llvm::ArrayType::get(ptrTy, arrayElementCount);
-  llvm::StructType *vtableTy = llvm::StructType::get(context, vtableArrayTy, false);
+  assert(spiceStruct->vtableType);
 
   // Generate VTable values
   std::vector<llvm::Constant *> arrayValues;
@@ -135,7 +135,7 @@ void IRGenerator::generateVTableInitializer(StructBase *spiceStruct) {
   // Generate VTable struct
   std::vector<llvm::Constant *> fieldValues;
   fieldValues.push_back(llvm::ConstantArray::get(vtableArrayTy, arrayValues));
-  llvm::Constant *initializer = llvm::ConstantStruct::get(vtableTy, fieldValues);
+  llvm::Constant *initializer = llvm::ConstantStruct::get(spiceStruct->vtableType, fieldValues);
 
   const std::string mangledName = NameMangling::mangleVTable(spiceStruct);
   llvm::GlobalVariable *global = module->getNamedGlobal(mangledName);
diff --git a/src/irgenerator/GenValues.cpp b/src/irgenerator/GenValues.cpp
index f7a34f9be..94e8d6262 100644
--- a/src/irgenerator/GenValues.cpp
+++ b/src/irgenerator/GenValues.cpp
@@ -339,7 +339,7 @@ std::any IRGenerator::visitStructInstantiation(const StructInstantiationNode *no
 
   // Get struct type
   assert(spiceStruct->entry != nullptr);
-  llvm::StructType *structType = spiceStruct->entry->getStructLLVMType();
+  auto structType = reinterpret_cast<llvm::StructType *>(spiceStruct->entry->getType().toLLVMType(context, currentScope));
   assert(structType != nullptr);
 
   if (!node->fieldLst()) {
@@ -431,7 +431,7 @@ std::any IRGenerator::visitLambdaFunc(const LambdaFuncNode *node) {
         captureType = capture.second.capturedEntry->getType().toLLVMType(context, currentScope);
       captureTypes.push_back(captureType);
     }
-    capturesStructType = llvm::StructType::create(context, captureTypes, getUnusedGlobalName(ANON_GLOBAL_CAPTURES_ARRAY_NAME));
+    capturesStructType = llvm::StructType::get(context, captureTypes);
     // Add the captures struct as first parameter
     paramInfoList.emplace_back(CAPTURES_PARAM_NAME, nullptr);
     paramTypes.push_back(builder.getPtrTy()); // The capture struct is always passed as pointer
@@ -602,7 +602,7 @@ std::any IRGenerator::visitLambdaProc(const LambdaProcNode *node) {
         captureType = capture.second.capturedEntry->getType().toLLVMType(context, currentScope);
       captureTypes.push_back(captureType);
     }
-    capturesStructType = llvm::StructType::create(context, captureTypes, getUnusedGlobalName(ANON_GLOBAL_CAPTURES_ARRAY_NAME));
+    capturesStructType = llvm::StructType::get(context, captureTypes);
     // Add the captures struct as first parameter
     paramInfoList.emplace_back(CAPTURES_PARAM_NAME, nullptr);
     paramTypes.push_back(builder.getPtrTy()); // The captures struct is always passed as pointer
@@ -760,7 +760,7 @@ std::any IRGenerator::visitLambdaExpr(const LambdaExprNode *node) {
         captureType = capture.second.capturedEntry->getType().toLLVMType(context, currentScope);
       captureTypes.push_back(captureType);
     }
-    capturesStructType = llvm::StructType::create(context, captureTypes, getUnusedGlobalName(ANON_GLOBAL_CAPTURES_ARRAY_NAME));
+    capturesStructType = llvm::StructType::get(context, captureTypes);
     // Add the captures struct as first parameter
     paramInfoList.emplace_back(CAPTURES_PARAM_NAME, nullptr);
     paramTypes.push_back(builder.getPtrTy()); // The capture struct is always passed as pointer
diff --git a/src/irgenerator/IRGenerator.h b/src/irgenerator/IRGenerator.h
index 80d02baf1..7519518b4 100644
--- a/src/irgenerator/IRGenerator.h
+++ b/src/irgenerator/IRGenerator.h
@@ -14,8 +14,6 @@ namespace spice::compiler {
 
 const char *const ANON_GLOBAL_STRING_NAME = "anon.string.";
 const char *const ANON_GLOBAL_ARRAY_NAME = "anon.array.";
-const char *const ANON_GLOBAL_STRUCT_NAME = "anon.struct.";
-const char *const ANON_GLOBAL_CAPTURES_ARRAY_NAME = "anon.captures.";
 const char *const CAPTURES_PARAM_NAME = "captures";
 
 enum Likeliness { UNSPECIFIED, LIKELY, UNLIKELY };
diff --git a/src/irgenerator/OpRuleConversionManager.cpp b/src/irgenerator/OpRuleConversionManager.cpp
index 5c611b9f2..8ae49ab52 100644
--- a/src/irgenerator/OpRuleConversionManager.cpp
+++ b/src/irgenerator/OpRuleConversionManager.cpp
@@ -495,12 +495,20 @@ LLVMExprResult OpRuleConversionManager::getEqualInst(const ASTNode *node, LLVMEx
   if (lhsSTy.isPtr() && rhsSTy.isPtr())
     return {.value = builder.CreateICmpEQ(lhsV(), rhsV())};
 
-  // Check if one value is of type pointer and one is of type int
+  // Check if lhs is of type pointer and rhs is of type int
   if (lhsT->isPointerTy() && rhsT->isIntegerTy(32)) {
     llvm::Value *lhsInt = builder.CreatePtrToInt(lhsV(), rhsT);
     return {.value = builder.CreateICmpEQ(lhsInt, rhsV())};
   }
 
+  // Check if one value is a string and the other one is a char*
+  if ((lhsSTy.is(TY_STRING) && rhsSTy.isPtrOf(TY_CHAR)) || (lhsSTy.isPtrOf(TY_CHAR) && rhsSTy.is(TY_STRING))) {
+    // Generate call to the function isRawEqual(string, string) of the string std
+    llvm::Function *opFct = stdFunctionManager.getStringIsRawEqualStringStringFct();
+    llvm::Value *result = builder.CreateCall(opFct, {lhsV(), rhsV()});
+    return {.value = result};
+  }
+
   // Check for primitive type combinations
   switch (getTypeCombination(lhsSTy, rhsSTy)) {
   case COMB(TY_DOUBLE, TY_DOUBLE):
@@ -620,12 +628,21 @@ LLVMExprResult OpRuleConversionManager::getNotEqualInst(const ASTNode *node, LLV
   if (lhsSTy.isPtr() && rhsSTy.isPtr())
     return {.value = builder.CreateICmpNE(lhsV(), rhsV())};
 
-  // Check if one value is of type pointer and one is of type int
+  // Check if lhs is of type pointer and rhs is of type int
   if (lhsT->isPointerTy() && rhsT->isIntegerTy(32)) {
     llvm::Value *lhsInt = builder.CreatePtrToInt(lhsV(), rhsT);
     return {.value = builder.CreateICmpNE(lhsInt, rhsV())};
   }
 
+  // Check if one value is a string and the other one is a char*
+  if ((lhsSTy.is(TY_STRING) && rhsSTy.isPtrOf(TY_CHAR)) || (lhsSTy.isPtrOf(TY_CHAR) && rhsSTy.is(TY_STRING))) {
+    // Generate call to the function isRawEqual(string, string) of the string std
+    llvm::Function *opFct = stdFunctionManager.getStringIsRawEqualStringStringFct();
+    llvm::Value *result = builder.CreateCall(opFct, {lhsV(), rhsV()});
+    // Negate the result
+    return {.value = builder.CreateNot(result)};
+  }
+
   switch (getTypeCombination(lhsSTy, rhsSTy)) {
   case COMB(TY_DOUBLE, TY_DOUBLE):
     return {.value = builder.CreateFCmpONE(lhsV(), rhsV())};
@@ -1592,10 +1609,9 @@ LLVMExprResult OpRuleConversionManager::getCastInst(const ASTNode *node, SymbolT
   case COMB(TY_STRING, TY_STRING): // fallthrough
   case COMB(TY_STRING, TY_PTR):    // fallthrough
   case COMB(TY_BOOL, TY_BOOL):     // fallthrough
-  case COMB(TY_PTR, TY_STRING):
-    return {.value = rhsV()};
+  case COMB(TY_PTR, TY_STRING):    // fallthrough
   case COMB(TY_PTR, TY_PTR):
-    return {.value = lhsSTy.getContainedTy() == rhsSTy.getContainedTy() ? rhsV() : builder.CreatePointerCast(rhsV(), lhsT)};
+    return {.value = rhsV()};
   }
   throw CompilerError(UNHANDLED_BRANCH, "Operator fallthrough: (cast)"); // GCOV_EXCL_LINE
 }
diff --git a/src/irgenerator/StdFunctionManager.cpp b/src/irgenerator/StdFunctionManager.cpp
index 407bedb15..84f50fb97 100644
--- a/src/irgenerator/StdFunctionManager.cpp
+++ b/src/irgenerator/StdFunctionManager.cpp
@@ -19,6 +19,16 @@ llvm::Function *StdFunctionManager::getPrintfFct() const {
   return printfFct;
 }
 
+llvm::Function *StdFunctionManager::getFreeFctPtr() const {
+  llvm::Function *freeFct = getProcedure("free", builder.getPtrTy());
+  // Set attributes
+  freeFct->addFnAttr(llvm::Attribute::NoUnwind);
+  freeFct->addParamAttr(0, llvm::Attribute::NoCapture);
+  freeFct->addParamAttr(0, llvm::Attribute::NoUndef);
+  freeFct->addParamAttr(0, llvm::Attribute::ReadOnly);
+  return freeFct;
+}
+
 llvm::Function *StdFunctionManager::getExitFct() const {
   llvm::Function *exitFct = getProcedure("exit", builder.getInt32Ty());
   // Set attributes
diff --git a/src/irgenerator/StdFunctionManager.h b/src/irgenerator/StdFunctionManager.h
index b9e7e3c7b..60013e31c 100644
--- a/src/irgenerator/StdFunctionManager.h
+++ b/src/irgenerator/StdFunctionManager.h
@@ -21,6 +21,7 @@ class StdFunctionManager {
 
   // Public methods for function retrieval
   [[nodiscard]] llvm::Function *getPrintfFct() const;
+  [[nodiscard]] llvm::Function *getFreeFctPtr() const;
   [[nodiscard]] llvm::Function *getExitFct() const;
   [[nodiscard]] llvm::Function *getMemcpyIntrinsic() const;
   [[nodiscard]] llvm::Function *getMemcmpIntrinsic() const;
diff --git a/src/model/StructBase.cpp b/src/model/StructBase.cpp
index 777c1a57a..ed454947a 100644
--- a/src/model/StructBase.cpp
+++ b/src/model/StructBase.cpp
@@ -36,7 +36,7 @@ std::string StructBase::getSignature(const std::string &name, const std::vector<
     for (size_t i = 0; i < concreteTemplateTypes.size(); i++) {
       if (i > 0)
         templateTyStr << ",";
-      templateTyStr << concreteTemplateTypes.at(i).getName();
+      templateTyStr << concreteTemplateTypes.at(i).getName(false, true);
     }
     templateTyStr << ">";
   }
@@ -81,4 +81,4 @@ std::vector<SymbolType> StructBase::getTemplateTypes() const {
  */
 const CodeLoc &StructBase::getDeclCodeLoc() const { return declNode->codeLoc; }
 
-} // namespace spice::compiler
+} // namespace spice::compiler
\ No newline at end of file
diff --git a/src/symboltablebuilder/SymbolTable.cpp b/src/symboltablebuilder/SymbolTable.cpp
index 4616c7b5c..890932fa5 100644
--- a/src/symboltablebuilder/SymbolTable.cpp
+++ b/src/symboltablebuilder/SymbolTable.cpp
@@ -28,7 +28,7 @@ SymbolTableEntry *SymbolTable::insert(const std::string &name, ASTNode *declNode
   entry->updateState(DECLARED, declNode);
 
   // Check if shadowed
-  if (parent != nullptr && parent->lookup(name) != nullptr) {
+  if (parent != nullptr && parent->lookup(name) != nullptr && !declNode->isParamNode()) {
     CompilerWarning warning(declNode->codeLoc, SHADOWED_VARIABLE, "Variable '" + name + "' shadows a variable in a parent scope");
     scope->sourceFile->compilerOutput.warnings.push_back(warning);
   }
diff --git a/src/symboltablebuilder/SymbolTableBuilder.cpp b/src/symboltablebuilder/SymbolTableBuilder.cpp
index cec2d61bf..fd8c13e3d 100644
--- a/src/symboltablebuilder/SymbolTableBuilder.cpp
+++ b/src/symboltablebuilder/SymbolTableBuilder.cpp
@@ -320,6 +320,16 @@ std::any SymbolTableBuilder::visitAliasDef(AliasDefNode *node) {
   if (rootScope->lookupStrict(node->aliasName))
     throw SemanticError(node, DUPLICATE_SYMBOL, "Duplicate symbol '" + node->aliasName + "'");
 
+  // Build alias specifiers
+  if (SpecifierLstNode *specifierLst = node->specifierLst(); specifierLst) {
+    for (const SpecifierNode *specifier : specifierLst->specifiers()) {
+      if (specifier->type == SpecifierNode::TY_PUBLIC)
+        node->aliasSpecifiers.isPublic = true;
+      else
+        throw SemanticError(specifier, SPECIFIER_AT_ILLEGAL_CONTEXT, "Cannot use this specifier on an alias definition");
+    }
+  }
+
   // Add the alias to the symbol table
   node->entry = rootScope->insert(node->aliasName, node);
 
diff --git a/src/symboltablebuilder/SymbolType.cpp b/src/symboltablebuilder/SymbolType.cpp
index a984e7a19..e201782d3 100644
--- a/src/symboltablebuilder/SymbolType.cpp
+++ b/src/symboltablebuilder/SymbolType.cpp
@@ -3,6 +3,7 @@
 #include "SymbolType.h"
 
 #include <SourceFile.h>
+#include <ast/Attributes.h>
 #include <exception/CompilerError.h>
 #include <exception/SemanticError.h>
 #include <irgenerator/NameMangling.h>
@@ -173,28 +174,47 @@ llvm::Type *SymbolType::toLLVMType(llvm::LLVMContext &context, Scope *accessScop
 
     // If the type is not known yet, build the LLVM type
     if (!structType) {
-      Struct *spiceStruct = structSymbol->getType().getStruct(structSymbol->declNode);
-      assert(spiceStruct != nullptr);
-      const std::string mangledName = NameMangling::mangleStruct(*spiceStruct);
-      structType = llvm::StructType::create(context, mangledName);
-      structSymbol->setStructLLVMType(structType);
-
       // Collect concrete field types
       std::vector<llvm::Type *> fieldTypes;
+      bool isPacked = false;
       if (is(TY_STRUCT)) { // Struct
+        Struct *spiceStruct = structSymbol->getType().getStruct(structSymbol->declNode);
+        assert(spiceStruct != nullptr);
+        const std::string mangledName = NameMangling::mangleStruct(*spiceStruct);
+        structType = llvm::StructType::create(context, mangledName);
+        structSymbol->setStructLLVMType(structType);
+
         const size_t totalFieldCount = spiceStruct->scope->getFieldCount();
         fieldTypes.reserve(totalFieldCount);
+
+        // If the struct has no interface types, but a vtable was requested, add another ptr field type
+        assert(structSymbol->declNode->isStructDef());
+        auto structDeclNode = spice_pointer_cast<StructDefNode *>(structSymbol->declNode);
+        if (!structDeclNode->hasInterfaces && structDeclNode->emitVTable)
+          fieldTypes.push_back(llvm::PointerType::get(context, 0));
+
+        // Collect all field types
         for (size_t i = 0; i < totalFieldCount; i++) {
           const SymbolTableEntry *fieldSymbol = spiceStruct->scope->symbolTable.lookupStrictByIndex(i);
           assert(fieldSymbol != nullptr);
           fieldTypes.push_back(fieldSymbol->getType().toLLVMType(context, accessScope));
         }
+
+        // Check if the struct is declared as packed
+        if (structDeclNode->attrs() && structDeclNode->attrs()->attrLst()->hasAttr(ATTR_CORE_COMPILER_PACKED))
+          isPacked = structDeclNode->attrs()->attrLst()->getAttrValueByName(ATTR_CORE_COMPILER_PACKED)->boolValue;
       } else { // Interface
+        Interface *spiceInterface = structSymbol->getType().getInterface(structSymbol->declNode);
+        assert(spiceInterface != nullptr);
+        const std::string mangledName = NameMangling::mangleInterface(*spiceInterface);
+        structType = llvm::StructType::create(context, mangledName);
+        structSymbol->setStructLLVMType(structType);
+
         fieldTypes.push_back(llvm::PointerType::get(context, 0));
       }
 
       // Set field types to struct type
-      structType->setBody(fieldTypes);
+      structType->setBody(fieldTypes, isPacked);
     }
 
     return structType;
@@ -381,14 +401,15 @@ bool SymbolType::isCoveredByGenericTypeList(std::vector<GenericType> &genericTyp
  * Get the name of the symbol type as a string
  *
  * @param withSize Include the array size for sized types
+ * @param ignorePublic Ignore any potential public specifier
  * @return Symbol type name
  */
-std::string SymbolType::getName(bool withSize) const { // NOLINT(misc-no-recursion)
+std::string SymbolType::getName(bool withSize, bool ignorePublic) const { // NOLINT(misc-no-recursion)
   std::stringstream name;
 
   // Append the specifiers
   const TypeSpecifiers defaultForSuperType = TypeSpecifiers::of(getBaseType().getSuperType());
-  if (specifiers.isPublic && !defaultForSuperType.isPublic)
+  if (!ignorePublic && specifiers.isPublic && !defaultForSuperType.isPublic)
     name << "public ";
   if (specifiers.isInline && !defaultForSuperType.isInline)
     name << "inline ";
@@ -565,11 +586,8 @@ bool SymbolType::matches(const SymbolType &otherType, bool ignoreArraySize, bool
       return false;
   }
 
-  // Ignore difference of specifiers
-  if (ignoreSpecifiers && !isPtr() && !isRef())
-    return true;
-
-  return specifiers.match(otherType.specifiers, allowConstify);
+  // Ignore or compare specifiers
+  return ignoreSpecifiers || specifiers.match(otherType.specifiers, allowConstify);
 }
 
 /**
diff --git a/src/symboltablebuilder/SymbolType.h b/src/symboltablebuilder/SymbolType.h
index d111dd975..7ab7360fe 100644
--- a/src/symboltablebuilder/SymbolType.h
+++ b/src/symboltablebuilder/SymbolType.h
@@ -84,6 +84,7 @@ class SymbolType {
     friend bool operator==(const TypeChainElement &lhs, const TypeChainElement &rhs);
     friend bool operator!=(const TypeChainElement &lhs, const TypeChainElement &rhs);
     [[nodiscard]] std::string getName(bool withSize) const;
+    [[nodiscard]] std::string getOriginalSubType() const;
 
     // Public members
     SymbolSuperType superType = TY_DYN;
@@ -158,7 +159,7 @@ class SymbolType {
   }
   [[nodiscard]] ALWAYS_INLINE std::string getOriginalSubType() const {
     assert(isOneOf({TY_STRUCT, TY_INTERFACE, TY_ENUM, TY_GENERIC}));
-    return CommonUtil::getLastFragment(typeChain.back().subType, SCOPE_ACCESS_TOKEN);
+    return typeChain.back().getOriginalSubType();
   }
   [[nodiscard]] ALWAYS_INLINE SymbolType removeReferenceWrapper() const { return isRef() ? getContainedTy() : *this; }
   [[nodiscard]] SymbolType getBaseType() const {
@@ -170,7 +171,7 @@ class SymbolType {
   void setBaseTemplateTypes(const std::vector<SymbolType> &templateTypes);
   [[nodiscard]] const std::vector<SymbolType> &getTemplateTypes() const;
   [[nodiscard]] bool isCoveredByGenericTypeList(std::vector<GenericType> &genericTypeList) const;
-  [[nodiscard]] std::string getName(bool withSize = false) const;
+  [[nodiscard]] std::string getName(bool withSize = false, bool ignorePublic = false) const;
   [[nodiscard]] ALWAYS_INLINE size_t getArraySize() const {
     assert(getSuperType() == TY_ARRAY);
     return typeChain.back().data.arraySize;
diff --git a/src/symboltablebuilder/TypeChain.cpp b/src/symboltablebuilder/TypeChain.cpp
index 4736c28bb..2d62d94aa 100644
--- a/src/symboltablebuilder/TypeChain.cpp
+++ b/src/symboltablebuilder/TypeChain.cpp
@@ -78,16 +78,18 @@ std::string SymbolType::TypeChainElement::getName(bool withSize) const {
     return "bool";
   case TY_STRUCT: // fall-through
   case TY_INTERFACE: {
-    std::string templateStr;
+    std::stringstream name;
+    name << subType;
     if (!templateTypes.empty()) {
-      for (const auto &templateType : templateTypes) {
-        if (!templateStr.empty())
-          templateStr += ",";
-        templateStr += templateType.getName();
+      name << "<";
+      for (size_t i = 0; i < templateTypes.size(); i++) {
+        if (i > 0)
+          name << ",";
+        name << templateTypes.at(i).getName();
       }
-      templateStr = "<" + templateStr + ">";
+      name << ">";
     }
-    return subType + templateStr;
+    return name.str();
   }
   case TY_ENUM:
     return "enum";
@@ -133,4 +135,13 @@ std::string SymbolType::TypeChainElement::getName(bool withSize) const {
   }
 }
 
+/**
+ * Get the original sub type, without any namespace information
+ *
+ * @return last fragment of sub type
+ */
+std::string SymbolType::TypeChainElement::getOriginalSubType() const {
+  return CommonUtil::getLastFragment(subType, SCOPE_ACCESS_TOKEN);
+}
+
 } // namespace spice::compiler
\ No newline at end of file
diff --git a/src/typechecker/OpRuleManager.cpp b/src/typechecker/OpRuleManager.cpp
index 08e9a0fe2..2c96af664 100644
--- a/src/typechecker/OpRuleManager.cpp
+++ b/src/typechecker/OpRuleManager.cpp
@@ -294,6 +294,10 @@ ExprResult OpRuleManager::getEqualResultType(ASTNode *node, SymbolType lhs, Symb
   if (lhs.isPtr() && rhs.is(TY_INT))
     return ExprResult(SymbolType(TY_BOOL));
 
+  // Allow 'string == char*' and vice versa straight away
+  if ((lhs.is(TY_STRING) && rhs.isPtrOf(TY_CHAR)) || (lhs.isPtrOf(TY_CHAR) && rhs.is(TY_STRING)))
+    return ExprResult(SymbolType(TY_BOOL));
+
   // Check primitive type combinations
   return ExprResult(validateBinaryOperation(node, EQUAL_OP_RULES, ARRAY_LENGTH(EQUAL_OP_RULES), "==", lhs, rhs));
 }
@@ -316,6 +320,10 @@ ExprResult OpRuleManager::getNotEqualResultType(ASTNode *node, SymbolType lhs, S
   if (lhs.isPtr() && rhs.is(TY_INT))
     return ExprResult(SymbolType(TY_BOOL));
 
+  // Allow 'string != char*' and vice versa straight away
+  if ((lhs.is(TY_STRING) && rhs.isPtrOf(TY_CHAR)) || (lhs.isPtrOf(TY_CHAR) && rhs.is(TY_STRING)))
+    return ExprResult(SymbolType(TY_BOOL));
+
   // Check primitive type combinations
   return ExprResult(validateBinaryOperation(node, NOT_EQUAL_OP_RULES, ARRAY_LENGTH(NOT_EQUAL_OP_RULES), "!=", lhs, rhs));
 }
diff --git a/src/typechecker/StructManager.cpp b/src/typechecker/StructManager.cpp
index 1e32c9285..73b6363f9 100644
--- a/src/typechecker/StructManager.cpp
+++ b/src/typechecker/StructManager.cpp
@@ -224,7 +224,18 @@ bool StructManager::matchTemplateTypes(Struct &candidate, const std::vector<Symb
  * @param typeMapping Generic type mapping
  */
 void StructManager::substantiateFieldTypes(Struct &candidate, TypeMapping &typeMapping) {
-  // Loop over all field types and substantiate the generic ones
+  // Loop over all implicit fields and substantiate the generic ones
+  const size_t fieldCount = candidate.scope->getFieldCount() - candidate.fieldTypes.size();
+  for (size_t i = 0; i < fieldCount; i++) {
+    SymbolTableEntry *fieldEntry = candidate.scope->symbolTable.lookupStrictByIndex(i);
+    SymbolType fieldType = fieldEntry->getType();
+    if (fieldType.hasAnyGenericParts()) {
+      TypeMatcher::substantiateTypeWithTypeMapping(fieldType, typeMapping);
+      fieldEntry->updateType(fieldType, true);
+    }
+  }
+
+  // Loop over all explicit field types and substantiate the generic ones
   for (SymbolType &fieldType : candidate.fieldTypes)
     if (fieldType.hasAnyGenericParts())
       TypeMatcher::substantiateTypeWithTypeMapping(fieldType, typeMapping);
diff --git a/src/typechecker/TypeChecker.cpp b/src/typechecker/TypeChecker.cpp
index 918276d58..035a1a931 100644
--- a/src/typechecker/TypeChecker.cpp
+++ b/src/typechecker/TypeChecker.cpp
@@ -1502,8 +1502,14 @@ std::any TypeChecker::visitFctCall(FctCallNode *node) {
   }
 
   // Retrieve entry of the first fragment
-  SymbolTableEntry *firstFragEntry = currentScope->lookup(node->functionNameFragments.front());
+  const std::string &firstFrag = node->functionNameFragments.front();
+  SymbolTableEntry *firstFragEntry = currentScope->lookup(firstFrag);
   if (firstFragEntry) {
+    // Check if we have seen a 'this.' prefix, because the generator needs that
+    if (firstFragEntry->scope->type == ScopeType::STRUCT && firstFrag != THIS_VARIABLE_NAME)
+      SOFT_ERROR_ER(node, REFERENCED_UNDEFINED_VARIABLE,
+                    "The symbol '" + firstFrag + "' could not be found. Missing 'this.' prefix?")
+
     firstFragEntry->used = true;
     // Decide of which type the function call is
     const SymbolType &baseType = firstFragEntry->getType().getBaseType();
@@ -2232,6 +2238,11 @@ std::any TypeChecker::visitCustomDataType(CustomDataTypeNode *node) {
     SymbolType symbolType = *genericType;
     if (typeMapping.contains(firstFragment))
       symbolType = typeMapping.at(firstFragment);
+
+    // Check if the replacement is a String type
+    if (!isImported && symbolType.isStringObj() && !sourceFile->isStringRT())
+      sourceFile->requestRuntimeModule(STRING_RT);
+
     return node->setEvaluatedSymbolType(symbolType, manIdx);
   }
 
diff --git a/src/typechecker/TypeCheckerImplicit.cpp b/src/typechecker/TypeCheckerImplicit.cpp
index a7ea99b27..8bb8501b5 100644
--- a/src/typechecker/TypeCheckerImplicit.cpp
+++ b/src/typechecker/TypeCheckerImplicit.cpp
@@ -203,7 +203,8 @@ void TypeChecker::createDefaultDtorIfRequired(const Struct &spiceStruct, Scope *
   createDefaultStructMethod(spiceStruct, DTOR_FUNCTION_NAME, {});
 
   // Request memory runtime if we have fields, that are allocated on the heap
-  if (hasHeapFields) {
+  // The string runtime does not use it, but allocates manually to avoid circular dependencies
+  if (hasHeapFields && !sourceFile->isStringRT()) {
     SourceFile *memoryRT = sourceFile->requestRuntimeModule(MEMORY_RT);
     assert(memoryRT != nullptr);
     Scope *matchScope = memoryRT->globalScope.get();
diff --git a/src/typechecker/TypeCheckerPrepare.cpp b/src/typechecker/TypeCheckerPrepare.cpp
index 9ddb3eba3..f56cd257c 100644
--- a/src/typechecker/TypeCheckerPrepare.cpp
+++ b/src/typechecker/TypeCheckerPrepare.cpp
@@ -569,8 +569,9 @@ std::any TypeChecker::visitAliasDefPrepare(AliasDefNode *node) {
   assert(node->entry != nullptr && node->aliasedTypeContainerEntry != nullptr);
 
   // Update type of alias entry
-  const SymbolType symbolType(TY_ALIAS, node->dataTypeString);
-  node->entry->updateType(symbolType, false);
+  SymbolType aliasType(TY_ALIAS, node->dataTypeString);
+  aliasType.specifiers = node->aliasSpecifiers;
+  node->entry->updateType(aliasType, false);
 
   // Update type of the aliased type container entry
   auto aliasedType = std::any_cast<SymbolType>(visit(node->dataType()));
diff --git a/std/io/file_linux.spice b/std/io/file_linux.spice
index a74f05a74..f253c7fe0 100644
--- a/std/io/file_linux.spice
+++ b/std/io/file_linux.spice
@@ -1,3 +1,6 @@
+import "std/type/result";
+import "std/type/error";
+
 // File open modes
 public const string MODE_READ                 = "r";
 public const string MODE_WRITE                = "w";
@@ -20,9 +23,7 @@ const int SEEK_SET = 0;
 const int SEEK_CUR = 1;
 const int SEEK_END = 2;
 
-public type FilePtr struct {
-    byte* ptr
-}
+public type FilePtr alias byte*;
 
 public type File struct {
     FilePtr* filePtr
@@ -57,11 +58,9 @@ public f<int> createFile(string path) {
  *
  * @return File pointer
  */
-public f<File> openFile(string path, string mode) {
+public f<Result<File>> openFile(string path, string mode) {
     FilePtr* fp = fopen(path, mode);
-    // Insert check for pointer being 0 and throw an exception
-    File openedFile = File { fp };
-    return openedFile;
+    return fp != nil<FilePtr*> ? ok(fp) : err(fp, Error("Failed to open file '" + path + "'"));
 }
 
 /**
@@ -117,14 +116,28 @@ public f<long> File.getSize() {
     return size;
 }
 
+/**
+ * Checks if the end of the file is reached.
+ *
+ * @return EOF reached / not reached
+ */
+public f<bool> File.isEOF() {
+    return this.readChar() == EOF;
+}
+
 /**
  * Reads a whole file from a given path.
  *
  * @return Content in form of a string
  */
-public f<String> readFile(string path) {
+public f<Result<String>> readFile(string path) {
     // Open the file in read mode
-    File file = openFile(path, MODE_READ);
+    Result<File> fileResult = openFile(path, MODE_READ);
+    // Check for errors
+    if (fileResult.isErr()) {
+        return err(String(), fileResult.getErr());
+    }
+    File file = fileResult.unwrap();
     // Read from the file char by char
     int buffer;
     String output = String();
@@ -133,7 +146,7 @@ public f<String> readFile(string path) {
     }
     // Close the file
     file.close();
-    return output;
+    return ok(output);
 }
 
 /**
@@ -141,14 +154,19 @@ public f<String> readFile(string path) {
  *
  * @return Result code of the write operation: 0 = successful, -1 = failed
  */
-public f<int> writeFile(string path, string content) {
+public f<Result<int>> writeFile(string path, string content) {
     // Open the file in write mode
-    File file = openFile(path, MODE_WRITE);
+    Result<File> fileResult = openFile(path, MODE_WRITE);
+    // Check for errors
+    if (fileResult.isErr()) {
+        return err(0, fileResult.getErr());
+    }
+    File file = fileResult.unwrap();
     // Write the string to the file
     int resultCode = file.writeString(content);
     // Close the file
     file.close();
-    return resultCode;
+    return ok(resultCode);
 }
 
 /**
@@ -156,14 +174,19 @@ public f<int> writeFile(string path, string content) {
  *
  * @return File size in bytes
  */
-public f<long> getFileSize(string path) {
+public f<Result<long>> getFileSize(string path) {
     // Open the file in read mode
-    File file = openFile(path, MODE_READ);
+    Result<File> fileResult = openFile(path, MODE_READ);
+    // Check for errors
+    if (fileResult.isErr()) {
+        return err(0l, fileResult.getErr());
+    }
+    File file = fileResult.unwrap();
     // Get the file size
     long size = file.getSize();
     // Close the file
     file.close();
-    return size;
+    return ok(size);
 }
 
 /**
diff --git a/std/io/file_windows.spice b/std/io/file_windows.spice
index f0199a02c..481a17670 100644
--- a/std/io/file_windows.spice
+++ b/std/io/file_windows.spice
@@ -1,3 +1,6 @@
+import "std/type/result";
+import "std/type/error";
+
 // File open modes
 public const string MODE_READ                 = "r";
 public const string MODE_WRITE                = "w";
@@ -20,9 +23,7 @@ const int SEEK_SET = 0;
 const int SEEK_CUR = 1;
 const int SEEK_END = 2;
 
-public type FilePtr struct {
-    byte* ptr
-}
+type FilePtr alias byte*;
 
 public type File struct {
     FilePtr* filePtr
@@ -57,11 +58,10 @@ public f<int> createFile(string path) {
  *
  * @return File pointer
  */
-public f<File> openFile(string path, string mode) {
+public f<Result<File>> openFile(string path, string mode) {
     FilePtr* fp = fopen(path, mode);
-    // Insert check for pointer being 0 and throw an exception
-    File openedFile = File { fp };
-    return openedFile;
+    File file = File{fp};
+    return fp != nil<FilePtr*> ? ok(file) : err(file, Error("Failed to open file"));
 }
 
 /**
@@ -117,14 +117,28 @@ public f<long> File.getSize() {
     return size;
 }
 
+/**
+ * Checks if the end of the file is reached.
+ *
+ * @return EOF reached / not reached
+ */
+public f<bool> File.isEOF() {
+    return this.readChar() == EOF;
+}
+
 /**
  * Reads a whole file from a given path.
  *
  * @return Content in form of a string
  */
-public f<String> readFile(string path) {
+public f<Result<String>> readFile(string path) {
     // Open the file in read mode
-    File file = openFile(path, MODE_READ);
+    Result<File> fileResult = openFile(path, MODE_READ);
+    // Check for errors
+    if !fileResult.isOk() {
+        return err(String(), fileResult.getErr());
+    }
+    File file = fileResult.unwrap();
     // Read from the file char by char
     int buffer;
     String output = String();
@@ -133,7 +147,7 @@ public f<String> readFile(string path) {
     }
     // Close the file
     file.close();
-    return output;
+    return ok(output);
 }
 
 /**
@@ -141,14 +155,19 @@ public f<String> readFile(string path) {
  *
  * @return Result code of the write operation: 0 = successful, -1 = failed
  */
-public f<int> writeFile(string path, string content) {
+public f<Result<int>> writeFile(string path, string content) {
     // Open the file in write mode
-    File file = openFile(path, MODE_WRITE);
+    Result<File> fileResult = openFile(path, MODE_WRITE);
+    // Check for errors
+    if !fileResult.isOk() {
+        return err(0, fileResult.getErr());
+    }
+    File file = fileResult.unwrap();
     // Write the string to the file
     int resultCode = file.writeString(content);
     // Close the file
     file.close();
-    return resultCode;
+    return ok(resultCode);
 }
 
 /**
@@ -156,14 +175,19 @@ public f<int> writeFile(string path, string content) {
  *
  * @return File size in bytes
  */
-public f<long> getFileSize(string path) {
+public f<Result<long>> getFileSize(string path) {
     // Open the file in read mode
-    File file = openFile(path, MODE_READ);
-    // Get the file size
+    Result<File> fileResult = openFile(path, MODE_READ);
+    // Check for errors
+    if !fileResult.isOk() {
+        return err(0l, fileResult.getErr());
+    }
+    File file = fileResult.unwrap();
+    // Get the file file
     long size = file.getSize();
     // Close the file
     file.close();
-    return size;
+    return ok(size);
 }
 
 /**
diff --git a/std/runtime/memory_rt.spice b/std/runtime/memory_rt.spice
index 25e491428..845155845 100644
--- a/std/runtime/memory_rt.spice
+++ b/std/runtime/memory_rt.spice
@@ -40,6 +40,9 @@ public f<Result<heap byte*>> sRealloc(heap byte* ptr, unsigned long size) {
   * @return A pointer to the copied block, or an error if the copy failed.
   */
 public f<Result<heap byte*>> sCopy(heap byte* oldPtr, heap byte* newPtr, unsigned long size) {
+    if oldPtr == nil<heap byte*> | newPtr == nil<heap byte*> {
+        return err(nil<heap byte*>, "Cannot copy from or to nil pointer!");
+    }
     memcpy(newPtr, oldPtr, size);
     return ok(newPtr);
 }
@@ -51,6 +54,7 @@ public f<Result<heap byte*>> sCopy(heap byte* oldPtr, heap byte* newPtr, unsigne
   * @param ptr The pointer to the block to free.
   */
 public p sDealloc(heap byte*& ptr) {
+    if ptr == nil<heap byte*> { return; }
     free(ptr);
     ptr = nil<heap byte*>; // Zero out to prevent accidental double frees
 }
\ No newline at end of file
diff --git a/std/runtime/string_rt.spice b/std/runtime/string_rt.spice
index f46775c35..dbe532908 100644
--- a/std/runtime/string_rt.spice
+++ b/std/runtime/string_rt.spice
@@ -1,6 +1,13 @@
 #![core.compiler.alwaysKeepOnNameCollision = true]
 
-import "std/type/result";
+import "std/type/error";
+
+// Link external functions
+// We intentionally do not use the memory_rt here to avoid dependency circles
+ext f<heap char*> malloc(unsigned long);
+ext f<heap char*> realloc(heap char*, unsigned long);
+ext p free(heap char*);
+ext p memcpy(heap char*, heap char*, unsigned long);
 
 // Constants
 const unsigned long INITIAL_ALLOC_COUNT = 5l;
@@ -27,18 +34,13 @@ public p String.ctor(const string value = "") {
     this.length = getRawLength(value);
     this.capacity = this.length > INITIAL_ALLOC_COUNT ? this.length * RESIZE_FACTOR : INITIAL_ALLOC_COUNT;
 
-    // Allocate space for the initial number of elements
     unsafe {
+        // Allocate space for the initial number of elements
         unsigned long requiredBytes = this.capacity + 1l; // +1 because of null terminator
-        Result<heap byte*> allocResult = sAlloc(requiredBytes);
-        this.contents = (heap char*) allocResult.unwrap();
-    }
-
-    // Save initial value
-    unsafe {
-        for unsigned long i = 0l; i < this.length + 1l; i++ { // +1 because of null terminator
-            this.contents[i] = value[i];
-        }
+        this.contents = malloc(requiredBytes);
+        this.checkForOOM();
+        // Save initial value
+        memcpy(this.contents, (char*) value, this.length + 1l); // +1 because of null terminator
     }
 }
 
@@ -46,15 +48,13 @@ public p String.ctor(const char value) {
     this.length = 1l;
     this.capacity = INITIAL_ALLOC_COUNT;
 
-    // Allocate space for the initial number of elements
     unsafe {
+        // Allocate space for the initial number of elements
         unsigned long requiredBytes = this.capacity + 1l; // +1 because of null terminator
-        Result<heap byte*> allocResult = sAlloc(requiredBytes);
-        this.contents = (heap char*) allocResult.unwrap();
-    }
+        this.contents = malloc(requiredBytes);
+        this.checkForOOM();
 
-    // Save initial value
-    unsafe {
+        // Save initial value
         this.contents[0] = value;
         this.contents[1] = '\0';
     }
@@ -64,16 +64,35 @@ public p String.ctor(const String& value) {
     this.length = value.length;
     this.capacity = value.capacity;
 
-    // Allocate space
     unsafe {
+        // Allocate space
+        unsigned long requiredBytes = this.capacity + 1l; // +1 because of null terminator
+        this.contents = malloc(requiredBytes);
+        this.checkForOOM();
+
+        // Copy the contents from the other string
+        memcpy(this.contents, value.contents, value.length + 1l); // +1 because of null terminator
+    }
+}
+
+public p String.ctor<IntLong>(IntLong initialSize) {
+    this.length = (unsigned long) initialSize;
+    this.capacity = initialSize > INITIAL_ALLOC_COUNT ? (unsigned long) initialSize * RESIZE_FACTOR : INITIAL_ALLOC_COUNT;
+
+    unsafe {
+        // Allocate space for the initial number of elements
         unsigned long requiredBytes = this.capacity + 1l; // +1 because of null terminator
-        Result<heap byte*> allocResult = sAlloc(requiredBytes);
-        this.contents = (heap char*) allocResult.unwrap();
+        this.contents = malloc(requiredBytes);
+        this.checkForOOM();
+
+        // Save the initial value
+        this.contents[0] = '\0';
     }
+}
 
-    // Copy the contents from the other string
+public p String.dtor() {
     unsafe {
-        sCopy((heap byte*) value.contents, (heap byte*) this.contents, value.length + 1l); // +1 because of null terminator
+        free(this.contents);
     }
 }
 
@@ -443,11 +462,11 @@ public f<bool> String.replace(
         if needleLength != replacementLength {
             const heap char* oldSuffixAddr = startAddr + needleLength;
             const heap char* newSuffixAddr = startAddr + replacementLength;
-            sCopy((heap byte*) oldSuffixAddr, (heap byte*) newSuffixAddr, suffixLength + 1); // +1 because of null terminator
+            memcpy(newSuffixAddr, oldSuffixAddr, suffixLength + 1l); // +1 because of null terminator
         }
 
         // Replace needle with replacement
-        sCopy((heap byte*) replacement, (heap byte*) startAddr, replacementLength);
+        memcpy(startAddr, (char*) replacement, replacementLength);
     }
 
     // Update length
@@ -529,7 +548,7 @@ public f<String> String.getSubstring<IntLongShort>(unsigned IntLongShort startId
  */
 public p String.reserve<IntLongShort>(unsigned IntLongShort charCount) {
     if charCount > this.capacity {
-        this.resize(charCount);
+        this.resize((unsigned long) charCount);
     }
 }
 
@@ -538,18 +557,24 @@ public p String.reserve<IntLongShort>(unsigned IntLongShort charCount) {
  *
  * @param newLength new length of the string after resizing
  */
-p String.resize<IntLongShort>(unsigned IntLongShort newLength) {
+p String.resize(unsigned long newLength) {
     // Allocate the new memory
     unsafe {
         heap char* oldAddress = this.contents;
-        unsigned long requiredBytes = newLength + 1; // +1 because of null terminator
-        Result<heap byte*> allocResult = sRealloc((heap byte*) oldAddress, requiredBytes);
-        this.contents = (heap char*) allocResult.unwrap();
+        unsigned long requiredBytes = newLength + 1l; // +1 because of null terminator
+        this.contents = realloc(oldAddress, requiredBytes);
+        this.checkForOOM();
     }
     // Set new capacity
     this.capacity = newLength;
 }
 
+p String.checkForOOM() {
+    if this.contents == nil<heap byte*> {
+        panic(Error("Could not allocate enough memory for dynamic string object"));
+    }
+}
+
 // ======================================================= Static functions ======================================================
 
 /**
@@ -559,6 +584,9 @@ p String.resize<IntLongShort>(unsigned IntLongShort newLength) {
  * @return Length of the input string
  */
 public f<unsigned long> getRawLength(string input) {
+    // Handle nullptr gracefully
+    if (char*) input == nil<char*> { return 0l; }
+    // Otherwise count the chars until the null terminator
     result = 0l;
     while input[result] != '\0' {
         result++;
diff --git a/std/type/byte.spice b/std/type/byte.spice
index 5d849cea6..3a20fcb06 100644
--- a/std/type/byte.spice
+++ b/std/type/byte.spice
@@ -2,6 +2,9 @@ public const int SIZE = 8;
 public const int MIN_VALUE = 0;
 public const int MAX_VALUE = 255;
 
+// External functions
+ext f<unsigned int> snprintf(char*, unsigned long, string, byte);
+
 // Converts a byte to a double
 public f<double> toDouble(byte input) {
     return 0.0 + ((int) input);
@@ -28,9 +31,10 @@ public f<char> toChar(byte input) {
 }
 
 // Converts a byte to a string
-public f<string> toString(byte input) {
-    // ToDo: Impmenet
-    return "0";
+public f<String> toString(byte input) {
+    const unsigned int length = snprintf(nil<char*>, 0l, "%hhu", input);
+    result = String(length);
+    snprintf((char*) result.getRaw(), length + 1l, "%hhu", input);
 }
 
 // Converts a byte to a bool
diff --git a/std/type/char.spice b/std/type/char.spice
index 501d6e5a5..715e0e7f6 100644
--- a/std/type/char.spice
+++ b/std/type/char.spice
@@ -28,8 +28,9 @@ public f<byte> toByte(char input) {
 }
 
 // Converts a char to a string
-public f<string> toString(char input) {
-    return "0";
+public f<String> toString(char input) {
+    result = String();
+    result += input;
 }
 
 // Converts a char to a bool
diff --git a/std/type/double.spice b/std/type/double.spice
index 53e1f770a..9bcd55c85 100644
--- a/std/type/double.spice
+++ b/std/type/double.spice
@@ -2,6 +2,8 @@ public const int SIZE = 64;
 public const double MIN_VALUE = -1.7976931348623157e+308;
 public const double MAX_VALUE = 1.7976931348623157e+308;
 
+ext f<unsigned int> snprintf(char*, unsigned long, string, double);
+
 // Converts a double to an int
 public f<int> toInt(double input) {
     return (int) input;
@@ -18,9 +20,10 @@ public f<long> toLong(double input) {
 }
 
 // Converts a double to a string
-public f<string> toString(double input) {
-    // ToDo: Implement
-    return "";
+public f<String> toString(double input) {
+    const unsigned int length = snprintf(nil<char*>, 0l, "%f", input);
+    result = String(length); // Assuming this length is enough
+    snprintf((char*) result.getRaw(), length + 1l, "%f", input);
 }
 
 // Converts a double to a boolean
diff --git a/std/type/int.spice b/std/type/int.spice
index 1175b34d0..68f03337f 100644
--- a/std/type/int.spice
+++ b/std/type/int.spice
@@ -2,6 +2,9 @@ public const int SIZE = 32;
 public const int MIN_VALUE = -2147483648;
 public const int MAX_VALUE = 2147483647;
 
+// External functions
+ext f<unsigned int> snprintf(char*, unsigned long, string, int);
+
 // Converts an int to a double
 public f<double> toDouble(int input) {
     return 0.0 + input;
@@ -29,20 +32,9 @@ public f<char> toChar(int input) {
 
 // Converts an int to a string
 public f<String> toString(const int input) {
-    if input == 0 { return String("0"); }
-
-    String str;
-    bool isNeg = input < 0;
-    unsigned int uInput = isNeg ? -input : input;
-
-    while (uInput != 0) {
-        str.append((char) (uInput % 10 + 48 /* ASCII for '0' */));
-        uInput = uInput / 10;
-    }
-    if isNeg { str.append('-'); }
-
-    str.reverse();
-    return str;
+    const unsigned int length = snprintf(nil<char*>, 0l, "%d", input);
+    result = String(length);
+    snprintf((char*) result.getRaw(), length + 1l, "%d", input);
 }
 
 // Converts an int to a boolean
diff --git a/std/type/long.spice b/std/type/long.spice
index d11321773..cf573c9ef 100644
--- a/std/type/long.spice
+++ b/std/type/long.spice
@@ -2,9 +2,8 @@ public const int SIZE = 64;
 public const long MIN_VALUE = -9223372036854775808l;
 public const long MAX_VALUE = 9223372036854775807l;
 
-const int N_SMALL = 100;
-const string SMALLS_STRING_10 = "0123456789";
-const string SMALLS_STRING_100 = "00010203040506070809101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899";
+// External functions
+ext f<unsigned int> snprintf(char*, unsigned long, string, long);
 
 // Converts a long to a double
 public f<double> toDouble(long input) {
@@ -32,9 +31,10 @@ public f<char> toChar(long input) {
 }
 
 // Converts a long to a string
-public f<string> toString(long input) {
-    // ToDo: Implement (See https://github.com/golang/go/blob/master/src/strconv/itoa.go)
-    return "";
+public f<String> toString(long input) {
+    const unsigned int length = snprintf(nil<char*>, 0l, "%ld", input);
+    result = String(length);
+    snprintf((char*) result.getRaw(), length + 1l, "%ld", input);
 }
 
 // Converts a long to a boolean
diff --git a/std/type/result.spice b/std/type/result.spice
index 23c8ac204..d9dd54778 100644
--- a/std/type/result.spice
+++ b/std/type/result.spice
@@ -30,6 +30,20 @@ public inline f<T> Result.unwrap() {
     return this.data;
 }
 
+/**
+ * Return the enclosed error object.
+ */
+public inline f<Error> Result.getErr() {
+    return this.error;
+}
+
+/**
+ * Checks if the result contains any data.
+ */
+public inline f<bool> Result.isOk() {
+    return this.error.code == 0;
+}
+
 /**
  * Returns a result object with a value and no error.
  */
diff --git a/std/type/short.spice b/std/type/short.spice
index 6ef074627..86dbe7c62 100644
--- a/std/type/short.spice
+++ b/std/type/short.spice
@@ -2,6 +2,9 @@ public const int SIZE = 16;
 public const short MIN_VALUE = -32768s;
 public const short MAX_VALUE = 32767s;
 
+// External functions
+ext f<unsigned int> snprintf(char*, unsigned long, string, short);
+
 // Converts a short to a double
 public f<double> toDouble(short input) {
     return 0.0 + input;
@@ -28,12 +31,13 @@ public f<char> toChar(short input) {
 }
 
 // Converts a short to a string
-public f<string> toString(short input) {
-    // ToDo: Implement (See https://github.com/golang/go/blob/master/src/strconv/itoa.go)
-    return "";
+public f<String> toString(short input) {
+    const unsigned int length = snprintf(nil<char*>, 0l, "%hd", input);
+    result = String(length);
+    snprintf((char*) result.getRaw(), length + 1l, "%hd", input);
 }
 
-// Converts a v to a boolean
+// Converts a short to a boolean
 public f<bool> toBool(short input) {
     return input >= 1;
 }
diff --git a/std/type/string.spice b/std/type/string.spice
index 73079f97a..970f10f71 100644
--- a/std/type/string.spice
+++ b/std/type/string.spice
@@ -1,33 +1,31 @@
 // External declarations
 ext f<long> strtol(string, char**, int);
+ext f<int> atoi(string, char**, int);
+ext f<double> strtod(string, char**);
 
 // Converts a string to a double
 public f<double> toDouble(string input) {
-    // ToDo: implement
-    return 0.0;
+    return strtod(input, nil<char**>);
 }
 
 // Converts a string to an int
 public f<int> toInt(string input, int base = 10) {
-    return (int) toLong(input, base);
+    return atoi(input, nil<char**>, base);
 }
 
 // Converts a string to a short
 public f<short> toShort(string input, int base = 10) {
-    return (short) toLong(input, base);
+    return (short) atoi(input, nil<char**>, base);
 }
 
 // Converts a string to a long
 public f<long> toLong(string input, int base = 10) {
-    char* endPtr = nil<char*>;
-    result = strtol(input, &endPtr, base);
-    // Check if the conversion was successful
-    if (((string) endPtr) == input || *endPtr != '\0') { return 0l; }
+    return strtol(input, nil<char**>, base);
 }
 
 // Converts a string to a byte
 public f<byte> toByte(string input, int base = 10) {
-    return (byte) ((int) toLong(input, base));
+    return (byte) atoi(input, nil<char**>, base);
 }
 
 // Converts a string to a char
diff --git a/test/test-files/irgenerator/debug-info/success-dbg-info-simple/ir-code.ll b/test/test-files/irgenerator/debug-info/success-dbg-info-simple/ir-code.ll
index 86d90c41b..4e0baef64 100644
--- a/test/test-files/irgenerator/debug-info/success-dbg-info-simple/ir-code.ll
+++ b/test/test-files/irgenerator/debug-info/success-dbg-info-simple/ir-code.ll
@@ -125,15 +125,15 @@ attributes #3 = { nofree nounwind }
 !30 = !DIDerivedType(tag: DW_TAG_member, name: "lng", scope: !28, file: !7, line: 2, baseType: !31, size: 64)
 !31 = !DIBasicType(name: "long", size: 64, encoding: DW_ATE_signed)
 !32 = !DIDerivedType(tag: DW_TAG_member, name: "str", scope: !28, file: !7, line: 3, baseType: !33, size: 192, align: 8, offset: 64)
-!33 = !DICompositeType(tag: DW_TAG_structure_type, name: "String", scope: !34, file: !34, line: 13, size: 192, align: 8, flags: DIFlagTypePassByValue | DIFlagNonTrivial, elements: !35, identifier: "struct.String")
+!33 = !DICompositeType(tag: DW_TAG_structure_type, name: "String", scope: !34, file: !34, line: 20, size: 192, align: 8, flags: DIFlagTypePassByValue | DIFlagNonTrivial, elements: !35, identifier: "struct.String")
 !34 = !DIFile(filename: "string_rt.spice", directory: "C:\\Users\\Marc\\Documents\\JustForFunGitHubClonesFast\\spice\\std\\runtime")
 !35 = !{!36, !39, !41}
-!36 = !DIDerivedType(tag: DW_TAG_member, name: "contents", scope: !33, file: !34, line: 14, baseType: !37, size: 64)
+!36 = !DIDerivedType(tag: DW_TAG_member, name: "contents", scope: !33, file: !34, line: 21, baseType: !37, size: 64)
 !37 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !38, size: 64)
 !38 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_unsigned_char)
-!39 = !DIDerivedType(tag: DW_TAG_member, name: "capacity", scope: !33, file: !34, line: 15, baseType: !40, size: 64, offset: 64)
+!39 = !DIDerivedType(tag: DW_TAG_member, name: "capacity", scope: !33, file: !34, line: 22, baseType: !40, size: 64, offset: 64)
 !40 = !DIBasicType(name: "unsigned long", size: 64, encoding: DW_ATE_unsigned)
-!41 = !DIDerivedType(tag: DW_TAG_member, name: "length", scope: !33, file: !34, line: 16, baseType: !40, size: 64, offset: 128)
+!41 = !DIDerivedType(tag: DW_TAG_member, name: "length", scope: !33, file: !34, line: 23, baseType: !40, size: 64, offset: 128)
 !42 = !DIDerivedType(tag: DW_TAG_member, name: "i", scope: !28, file: !7, line: 4, baseType: !43, size: 32, offset: 256)
 !43 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
 !44 = !{}
diff --git a/test/test-files/irgenerator/foreach-loops/success-foreach-loop-break/ir-code-O2.ll b/test/test-files/irgenerator/foreach-loops/success-foreach-loop-break/ir-code-O2.ll
index 67e616215..b96309dfe 100644
--- a/test/test-files/irgenerator/foreach-loops/success-foreach-loop-break/ir-code-O2.ll
+++ b/test/test-files/irgenerator/foreach-loops/success-foreach-loop-break/ir-code-O2.ll
@@ -3,9 +3,9 @@ source_filename = "source.spice"
 target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-w64-windows-gnu"
 
-%struct.NumberIterator = type { %interface.Iterable.1, i16, i16, i16 }
-%interface.Iterable.1 = type { ptr }
-%struct.NumberIterator.2 = type { %interface.Iterable.1, i64, i64, i64 }
+%struct.NumberIterator = type { %interface.Iterable, i16, i16, i16 }
+%interface.Iterable = type { ptr }
+%struct.NumberIterator.1 = type { %interface.Iterable, i64, i64, i64 }
 
 @printf.str.0 = private unnamed_addr constant [10 x i8] c"Short %d\0A\00", align 1
 @printf.str.1 = private unnamed_addr constant [9 x i8] c"Long %d\0A\00", align 1
@@ -14,7 +14,7 @@ target triple = "x86_64-w64-windows-gnu"
 ; Function Attrs: noinline nounwind optnone uwtable
 define dso_local i32 @main() local_unnamed_addr #0 {
   %shortIterator = alloca %struct.NumberIterator, align 8
-  %1 = alloca %struct.NumberIterator.2, align 8
+  %1 = alloca %struct.NumberIterator.1, align 8
   %2 = tail call %struct.NumberIterator @_Z5rangess(i16 3, i16 8) #2
   %.fca.0.0.extract2 = extractvalue %struct.NumberIterator %2, 0, 0
   store ptr %.fca.0.0.extract2, ptr %shortIterator, align 8
@@ -31,9 +31,9 @@ define dso_local i32 @main() local_unnamed_addr #0 {
   br i1 %3, label %foreach.body.L5.lr.ph, label %foreach.exit.L5
 
 foreach.body.L5.lr.ph:                            ; preds = %0
-  %.fca.1.gep = getelementptr inbounds %struct.NumberIterator.2, ptr %1, i64 0, i32 1
-  %.fca.2.gep = getelementptr inbounds %struct.NumberIterator.2, ptr %1, i64 0, i32 2
-  %.fca.3.gep = getelementptr inbounds %struct.NumberIterator.2, ptr %1, i64 0, i32 3
+  %.fca.1.gep = getelementptr inbounds %struct.NumberIterator.1, ptr %1, i64 0, i32 1
+  %.fca.2.gep = getelementptr inbounds %struct.NumberIterator.1, ptr %1, i64 0, i32 2
+  %.fca.3.gep = getelementptr inbounds %struct.NumberIterator.1, ptr %1, i64 0, i32 3
   br label %foreach.body.L5
 
 foreach.body.L5:                                  ; preds = %foreach.body.L5.lr.ph, %foreach.tail.L5
@@ -46,14 +46,14 @@ foreach.body.L5:                                  ; preds = %foreach.body.L5.lr.
   br i1 %.not, label %foreach.tail.L5, label %if.then.L7
 
 if.then.L7:                                       ; preds = %foreach.body.L5
-  %9 = call %struct.NumberIterator.2 @_Z5rangell(i64 1, i64 2) #2
-  %.fca.0.0.extract = extractvalue %struct.NumberIterator.2 %9, 0, 0
+  %9 = call %struct.NumberIterator.1 @_Z5rangell(i64 1, i64 2) #2
+  %.fca.0.0.extract = extractvalue %struct.NumberIterator.1 %9, 0, 0
   store ptr %.fca.0.0.extract, ptr %1, align 8
-  %.fca.1.extract = extractvalue %struct.NumberIterator.2 %9, 1
+  %.fca.1.extract = extractvalue %struct.NumberIterator.1 %9, 1
   store i64 %.fca.1.extract, ptr %.fca.1.gep, align 8
-  %.fca.2.extract = extractvalue %struct.NumberIterator.2 %9, 2
+  %.fca.2.extract = extractvalue %struct.NumberIterator.1 %9, 2
   store i64 %.fca.2.extract, ptr %.fca.2.gep, align 8
-  %.fca.3.extract = extractvalue %struct.NumberIterator.2 %9, 3
+  %.fca.3.extract = extractvalue %struct.NumberIterator.1 %9, 3
   store i64 %.fca.3.extract, ptr %.fca.3.gep, align 8
   %10 = call i1 @_ZN14NumberIteratorIlE7isValidEv(ptr nonnull %1) #2
   br i1 %10, label %foreach.body.L8, label %foreach.tail.L5
@@ -83,7 +83,7 @@ declare ptr @_ZN14NumberIteratorIsE3getEv(ptr) local_unnamed_addr
 ; Function Attrs: nofree nounwind
 declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1
 
-declare %struct.NumberIterator.2 @_Z5rangell(i64, i64) local_unnamed_addr
+declare %struct.NumberIterator.1 @_Z5rangell(i64, i64) local_unnamed_addr
 
 declare i1 @_ZN14NumberIteratorIlE7isValidEv(ptr) local_unnamed_addr
 
diff --git a/test/test-files/irgenerator/foreach-loops/success-foreach-loop-break/ir-code.ll b/test/test-files/irgenerator/foreach-loops/success-foreach-loop-break/ir-code.ll
index 50bdad982..cfd536c41 100644
--- a/test/test-files/irgenerator/foreach-loops/success-foreach-loop-break/ir-code.ll
+++ b/test/test-files/irgenerator/foreach-loops/success-foreach-loop-break/ir-code.ll
@@ -3,9 +3,9 @@ source_filename = "source.spice"
 target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-w64-windows-gnu"
 
-%struct.NumberIterator = type { %interface.Iterable.1, i16, i16, i16 }
-%interface.Iterable.1 = type { ptr }
-%struct.NumberIterator.2 = type { %interface.Iterable.1, i64, i64, i64 }
+%struct.NumberIterator = type { %interface.Iterable, i16, i16, i16 }
+%interface.Iterable = type { ptr }
+%struct.NumberIterator.1 = type { %interface.Iterable, i64, i64, i64 }
 
 @printf.str.0 = private unnamed_addr constant [10 x i8] c"Short %d\0A\00", align 1
 @printf.str.1 = private unnamed_addr constant [9 x i8] c"Long %d\0A\00", align 1
@@ -16,7 +16,7 @@ define dso_local i32 @main() #0 {
   %result = alloca i32, align 4
   %shortIterator = alloca %struct.NumberIterator, align 8
   %s = alloca i16, align 2
-  %1 = alloca %struct.NumberIterator.2, align 8
+  %1 = alloca %struct.NumberIterator.1, align 8
   %l = alloca ptr, align 8
   %2 = alloca ptr, align 8
   store i32 0, ptr %result, align 4
@@ -42,8 +42,8 @@ foreach.body.L5:                                  ; preds = %foreach.head.L5
   br i1 %13, label %if.then.L7, label %if.exit.L7
 
 if.then.L7:                                       ; preds = %foreach.body.L5
-  %14 = call %struct.NumberIterator.2 @_Z5rangell(i64 1, i64 2)
-  store %struct.NumberIterator.2 %14, ptr %1, align 8
+  %14 = call %struct.NumberIterator.1 @_Z5rangell(i64 1, i64 2)
+  store %struct.NumberIterator.1 %14, ptr %1, align 8
   br label %foreach.head.L8
 
 foreach.head.L8:                                  ; preds = %foreach.tail.L8, %if.then.L7
@@ -87,7 +87,7 @@ declare ptr @_ZN14NumberIteratorIsE3getEv(ptr)
 ; Function Attrs: nofree nounwind
 declare noundef i32 @printf(ptr nocapture noundef readonly, ...) #1
 
-declare %struct.NumberIterator.2 @_Z5rangell(i64, i64)
+declare %struct.NumberIterator.1 @_Z5rangell(i64, i64)
 
 declare i1 @_ZN14NumberIteratorIlE7isValidEv(ptr)
 
diff --git a/test/test-files/irgenerator/foreach-loops/success-foreach-loop-continue/ir-code-O2.ll b/test/test-files/irgenerator/foreach-loops/success-foreach-loop-continue/ir-code-O2.ll
index ba0b8844a..d49dd242e 100644
--- a/test/test-files/irgenerator/foreach-loops/success-foreach-loop-continue/ir-code-O2.ll
+++ b/test/test-files/irgenerator/foreach-loops/success-foreach-loop-continue/ir-code-O2.ll
@@ -3,9 +3,9 @@ source_filename = "source.spice"
 target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-w64-windows-gnu"
 
-%struct.NumberIterator = type { %interface.Iterable.1, i16, i16, i16 }
-%interface.Iterable.1 = type { ptr }
-%struct.NumberIterator.2 = type { %interface.Iterable.1, i64, i64, i64 }
+%struct.NumberIterator = type { %interface.Iterable, i16, i16, i16 }
+%interface.Iterable = type { ptr }
+%struct.NumberIterator.1 = type { %interface.Iterable, i64, i64, i64 }
 
 @printf.str.0 = private unnamed_addr constant [10 x i8] c"Short %d\0A\00", align 1
 @printf.str.1 = private unnamed_addr constant [9 x i8] c"Long %d\0A\00", align 1
@@ -14,7 +14,7 @@ target triple = "x86_64-w64-windows-gnu"
 ; Function Attrs: noinline nounwind optnone uwtable
 define dso_local i32 @main() local_unnamed_addr #0 {
   %shortIterator = alloca %struct.NumberIterator, align 8
-  %1 = alloca %struct.NumberIterator.2, align 8
+  %1 = alloca %struct.NumberIterator.1, align 8
   %2 = tail call %struct.NumberIterator @_Z5rangess(i16 3, i16 8) #2
   %.fca.0.0.extract2 = extractvalue %struct.NumberIterator %2, 0, 0
   store ptr %.fca.0.0.extract2, ptr %shortIterator, align 8
@@ -31,9 +31,9 @@ define dso_local i32 @main() local_unnamed_addr #0 {
   br i1 %3, label %foreach.body.L5.lr.ph, label %foreach.exit.L5
 
 foreach.body.L5.lr.ph:                            ; preds = %0
-  %.fca.1.gep = getelementptr inbounds %struct.NumberIterator.2, ptr %1, i64 0, i32 1
-  %.fca.2.gep = getelementptr inbounds %struct.NumberIterator.2, ptr %1, i64 0, i32 2
-  %.fca.3.gep = getelementptr inbounds %struct.NumberIterator.2, ptr %1, i64 0, i32 3
+  %.fca.1.gep = getelementptr inbounds %struct.NumberIterator.1, ptr %1, i64 0, i32 1
+  %.fca.2.gep = getelementptr inbounds %struct.NumberIterator.1, ptr %1, i64 0, i32 2
+  %.fca.3.gep = getelementptr inbounds %struct.NumberIterator.1, ptr %1, i64 0, i32 3
   br label %foreach.body.L5
 
 foreach.body.L5:                                  ; preds = %foreach.body.L5.lr.ph, %foreach.tail.L5
@@ -46,14 +46,14 @@ foreach.body.L5:                                  ; preds = %foreach.body.L5.lr.
   br i1 %.not, label %foreach.tail.L5, label %if.then.L7
 
 if.then.L7:                                       ; preds = %foreach.body.L5
-  %9 = call %struct.NumberIterator.2 @_Z5rangell(i64 1, i64 2) #2
-  %.fca.0.0.extract = extractvalue %struct.NumberIterator.2 %9, 0, 0
+  %9 = call %struct.NumberIterator.1 @_Z5rangell(i64 1, i64 2) #2
+  %.fca.0.0.extract = extractvalue %struct.NumberIterator.1 %9, 0, 0
   store ptr %.fca.0.0.extract, ptr %1, align 8
-  %.fca.1.extract = extractvalue %struct.NumberIterator.2 %9, 1
+  %.fca.1.extract = extractvalue %struct.NumberIterator.1 %9, 1
   store i64 %.fca.1.extract, ptr %.fca.1.gep, align 8
-  %.fca.2.extract = extractvalue %struct.NumberIterator.2 %9, 2
+  %.fca.2.extract = extractvalue %struct.NumberIterator.1 %9, 2
   store i64 %.fca.2.extract, ptr %.fca.2.gep, align 8
-  %.fca.3.extract = extractvalue %struct.NumberIterator.2 %9, 3
+  %.fca.3.extract = extractvalue %struct.NumberIterator.1 %9, 3
   store i64 %.fca.3.extract, ptr %.fca.3.gep, align 8
   %10 = call i1 @_ZN14NumberIteratorIlE7isValidEv(ptr nonnull %1) #2
   br i1 %10, label %foreach.body.L8, label %foreach.tail.L5
@@ -83,7 +83,7 @@ declare ptr @_ZN14NumberIteratorIsE3getEv(ptr) local_unnamed_addr
 ; Function Attrs: nofree nounwind
 declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1
 
-declare %struct.NumberIterator.2 @_Z5rangell(i64, i64) local_unnamed_addr
+declare %struct.NumberIterator.1 @_Z5rangell(i64, i64) local_unnamed_addr
 
 declare i1 @_ZN14NumberIteratorIlE7isValidEv(ptr) local_unnamed_addr
 
diff --git a/test/test-files/irgenerator/foreach-loops/success-foreach-loop-continue/ir-code.ll b/test/test-files/irgenerator/foreach-loops/success-foreach-loop-continue/ir-code.ll
index b1bc81bb1..272953c5d 100644
--- a/test/test-files/irgenerator/foreach-loops/success-foreach-loop-continue/ir-code.ll
+++ b/test/test-files/irgenerator/foreach-loops/success-foreach-loop-continue/ir-code.ll
@@ -3,9 +3,9 @@ source_filename = "source.spice"
 target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-w64-windows-gnu"
 
-%struct.NumberIterator = type { %interface.Iterable.1, i16, i16, i16 }
-%interface.Iterable.1 = type { ptr }
-%struct.NumberIterator.2 = type { %interface.Iterable.1, i64, i64, i64 }
+%struct.NumberIterator = type { %interface.Iterable, i16, i16, i16 }
+%interface.Iterable = type { ptr }
+%struct.NumberIterator.1 = type { %interface.Iterable, i64, i64, i64 }
 
 @printf.str.0 = private unnamed_addr constant [10 x i8] c"Short %d\0A\00", align 1
 @printf.str.1 = private unnamed_addr constant [9 x i8] c"Long %d\0A\00", align 1
@@ -16,7 +16,7 @@ define dso_local i32 @main() #0 {
   %result = alloca i32, align 4
   %shortIterator = alloca %struct.NumberIterator, align 8
   %s = alloca i16, align 2
-  %1 = alloca %struct.NumberIterator.2, align 8
+  %1 = alloca %struct.NumberIterator.1, align 8
   %l = alloca ptr, align 8
   %2 = alloca ptr, align 8
   store i32 0, ptr %result, align 4
@@ -42,8 +42,8 @@ foreach.body.L5:                                  ; preds = %foreach.head.L5
   br i1 %13, label %if.then.L7, label %if.exit.L7
 
 if.then.L7:                                       ; preds = %foreach.body.L5
-  %14 = call %struct.NumberIterator.2 @_Z5rangell(i64 1, i64 2)
-  store %struct.NumberIterator.2 %14, ptr %1, align 8
+  %14 = call %struct.NumberIterator.1 @_Z5rangell(i64 1, i64 2)
+  store %struct.NumberIterator.1 %14, ptr %1, align 8
   br label %foreach.head.L8
 
 foreach.head.L8:                                  ; preds = %foreach.tail.L8, %if.then.L7
@@ -87,7 +87,7 @@ declare ptr @_ZN14NumberIteratorIsE3getEv(ptr)
 ; Function Attrs: nofree nounwind
 declare noundef i32 @printf(ptr nocapture noundef readonly, ...) #1
 
-declare %struct.NumberIterator.2 @_Z5rangell(i64, i64)
+declare %struct.NumberIterator.1 @_Z5rangell(i64, i64)
 
 declare i1 @_ZN14NumberIteratorIlE7isValidEv(ptr)
 
diff --git a/test/test-files/irgenerator/generics/success-nested-generic-structs/ir-code.ll b/test/test-files/irgenerator/generics/success-nested-generic-structs/ir-code.ll
index 1cfed9a48..9c49011e3 100644
--- a/test/test-files/irgenerator/generics/success-nested-generic-structs/ir-code.ll
+++ b/test/test-files/irgenerator/generics/success-nested-generic-structs/ir-code.ll
@@ -3,14 +3,14 @@ source_filename = "source.spice"
 target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-w64-windows-gnu"
 
-%struct.Node.3 = type { ptr, double }
+%struct.Node = type { ptr, double }
 
 ; Function Attrs: noinline nounwind optnone uwtable
 define dso_local i32 @main() #0 {
   %result = alloca i32, align 4
-  %_node = alloca %struct.Node.3, align 8
+  %_node = alloca %struct.Node, align 8
   store i32 0, ptr %result, align 4
-  store %struct.Node.3 zeroinitializer, ptr %_node, align 8
+  store %struct.Node zeroinitializer, ptr %_node, align 8
   %1 = load i32, ptr %result, align 4
   ret i32 %1
 }
diff --git a/test/test-files/irgenerator/lambdas/success-captures/ir-code.ll b/test/test-files/irgenerator/lambdas/success-captures/ir-code.ll
index d29e21d41..6da290c64 100644
--- a/test/test-files/irgenerator/lambdas/success-captures/ir-code.ll
+++ b/test/test-files/irgenerator/lambdas/success-captures/ir-code.ll
@@ -3,9 +3,6 @@ source_filename = "source.spice"
 target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-w64-windows-gnu"
 
-%anon.captures.0 = type { i32, i32 }
-%anon.captures.0.0 = type { i32, i32 }
-
 @anon.string.0 = private unnamed_addr constant [57 x i8] c"Assertion failed: Condition 'x == 6' evaluated to false.\00", align 1
 @anon.string.1 = private unnamed_addr constant [58 x i8] c"Assertion failed: Condition 'foo2(x)' evaluated to false.\00", align 1
 @anon.string.2 = private unnamed_addr constant [58 x i8] c"Assertion failed: Condition 'x == 11' evaluated to false.\00", align 1
@@ -16,10 +13,10 @@ define dso_local i32 @main() #0 {
   %result = alloca i32, align 4
   %z = alloca i32, align 4
   %w = alloca i32, align 4
-  %captures = alloca %anon.captures.0, align 8
+  %captures = alloca { i32, i32 }, align 8
   %fat.ptr = alloca { ptr, ptr }, align 8
   %foo1 = alloca { ptr, ptr }, align 8
-  %captures1 = alloca %anon.captures.0.0, align 8
+  %captures1 = alloca { i32, i32 }, align 8
   %fat.ptr2 = alloca { ptr, ptr }, align 8
   %foo2 = alloca { ptr, ptr }, align 8
   %x = alloca i32, align 4
@@ -27,10 +24,10 @@ define dso_local i32 @main() #0 {
   store i32 2, ptr %z, align 4
   store i32 3, ptr %w, align 4
   %1 = load i32, ptr %w, align 4
-  %2 = getelementptr inbounds %anon.captures.0, ptr %captures, i32 0, i32 0
+  %2 = getelementptr inbounds { i32, i32 }, ptr %captures, i32 0, i32 0
   store i32 %1, ptr %2, align 4
   %3 = load i32, ptr %z, align 4
-  %4 = getelementptr inbounds %anon.captures.0, ptr %captures, i32 0, i32 1
+  %4 = getelementptr inbounds { i32, i32 }, ptr %captures, i32 0, i32 1
   store i32 %3, ptr %4, align 4
   %5 = getelementptr inbounds { ptr, ptr }, ptr %fat.ptr, i32 0, i32 0
   store ptr @_Z14lambda.L4C20.0Ri, ptr %5, align 8
@@ -39,10 +36,10 @@ define dso_local i32 @main() #0 {
   %7 = load { ptr, ptr }, ptr %fat.ptr, align 8
   store { ptr, ptr } %7, ptr %foo1, align 8
   %8 = load i32, ptr %w, align 4
-  %9 = getelementptr inbounds %anon.captures.0.0, ptr %captures1, i32 0, i32 0
+  %9 = getelementptr inbounds { i32, i32 }, ptr %captures1, i32 0, i32 0
   store i32 %8, ptr %9, align 4
   %10 = load i32, ptr %z, align 4
-  %11 = getelementptr inbounds %anon.captures.0.0, ptr %captures1, i32 0, i32 1
+  %11 = getelementptr inbounds { i32, i32 }, ptr %captures1, i32 0, i32 1
   store i32 %10, ptr %11, align 4
   %12 = getelementptr inbounds { ptr, ptr }, ptr %fat.ptr2, i32 0, i32 0
   store ptr @_Z14lambda.L7C26.0Ri, ptr %12, align 8
@@ -100,8 +97,8 @@ define private void @_Z14lambda.L4C20.0Ri(ptr noundef nonnull dereferenceable(8)
   store ptr %0, ptr %captures, align 8
   store ptr %1, ptr %x, align 8
   %3 = load ptr, ptr %captures, align 8
-  %w = getelementptr inbounds %anon.captures.0, ptr %3, i32 0, i32 0
-  %z = getelementptr inbounds %anon.captures.0, ptr %3, i32 0, i32 1
+  %w = getelementptr inbounds { i32, i32 }, ptr %3, i32 0, i32 0
+  %z = getelementptr inbounds { i32, i32 }, ptr %3, i32 0, i32 1
   %4 = load i32, ptr %w, align 4
   %5 = load i32, ptr %z, align 4
   %6 = add i32 %5, %4
@@ -119,8 +116,8 @@ define private i1 @_Z14lambda.L7C26.0Ri(ptr noundef nonnull dereferenceable(8) %
   store ptr %0, ptr %captures, align 8
   store ptr %1, ptr %x, align 8
   %3 = load ptr, ptr %captures, align 8
-  %w = getelementptr inbounds %anon.captures.0.0, ptr %3, i32 0, i32 0
-  %z = getelementptr inbounds %anon.captures.0.0, ptr %3, i32 0, i32 1
+  %w = getelementptr inbounds { i32, i32 }, ptr %3, i32 0, i32 0
+  %z = getelementptr inbounds { i32, i32 }, ptr %3, i32 0, i32 1
   %4 = load i32, ptr %w, align 4
   %5 = load i32, ptr %z, align 4
   %6 = add i32 %5, %4
diff --git a/test/test-files/irgenerator/lambdas/success-foreign-captures/ir-code.ll b/test/test-files/irgenerator/lambdas/success-foreign-captures/ir-code.ll
index a23b01837..c78de40ca 100644
--- a/test/test-files/irgenerator/lambdas/success-foreign-captures/ir-code.ll
+++ b/test/test-files/irgenerator/lambdas/success-foreign-captures/ir-code.ll
@@ -3,9 +3,6 @@ source_filename = "source.spice"
 target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-w64-windows-gnu"
 
-%anon.captures.0 = type { i32, i32 }
-%anon.captures.0.0 = type { i32, i32 }
-
 @anon.string.0 = private unnamed_addr constant [57 x i8] c"Assertion failed: Condition 'x == 6' evaluated to false.\00", align 1
 @anon.string.1 = private unnamed_addr constant [56 x i8] c"Assertion failed: Condition 'l2(x)' evaluated to false.\00", align 1
 @anon.string.2 = private unnamed_addr constant [58 x i8] c"Assertion failed: Condition 'x == 11' evaluated to false.\00", align 1
@@ -70,20 +67,20 @@ define dso_local i32 @main() #2 {
   %result = alloca i32, align 4
   %z = alloca i32, align 4
   %w = alloca i32, align 4
-  %captures = alloca %anon.captures.0, align 8
+  %captures = alloca { i32, i32 }, align 8
   %fat.ptr = alloca { ptr, ptr }, align 8
   %foo1 = alloca { ptr, ptr }, align 8
-  %captures1 = alloca %anon.captures.0.0, align 8
+  %captures1 = alloca { i32, i32 }, align 8
   %fat.ptr2 = alloca { ptr, ptr }, align 8
   %foo2 = alloca { ptr, ptr }, align 8
   store i32 0, ptr %result, align 4
   store i32 2, ptr %z, align 4
   store i32 3, ptr %w, align 4
   %1 = load i32, ptr %w, align 4
-  %2 = getelementptr inbounds %anon.captures.0, ptr %captures, i32 0, i32 0
+  %2 = getelementptr inbounds { i32, i32 }, ptr %captures, i32 0, i32 0
   store i32 %1, ptr %2, align 4
   %3 = load i32, ptr %z, align 4
-  %4 = getelementptr inbounds %anon.captures.0, ptr %captures, i32 0, i32 1
+  %4 = getelementptr inbounds { i32, i32 }, ptr %captures, i32 0, i32 1
   store i32 %3, ptr %4, align 4
   %5 = getelementptr inbounds { ptr, ptr }, ptr %fat.ptr, i32 0, i32 0
   store ptr @_Z15lambda.L12C20.0Ri, ptr %5, align 8
@@ -92,10 +89,10 @@ define dso_local i32 @main() #2 {
   %7 = load { ptr, ptr }, ptr %fat.ptr, align 8
   store { ptr, ptr } %7, ptr %foo1, align 8
   %8 = load i32, ptr %w, align 4
-  %9 = getelementptr inbounds %anon.captures.0.0, ptr %captures1, i32 0, i32 0
+  %9 = getelementptr inbounds { i32, i32 }, ptr %captures1, i32 0, i32 0
   store i32 %8, ptr %9, align 4
   %10 = load i32, ptr %z, align 4
-  %11 = getelementptr inbounds %anon.captures.0.0, ptr %captures1, i32 0, i32 1
+  %11 = getelementptr inbounds { i32, i32 }, ptr %captures1, i32 0, i32 1
   store i32 %10, ptr %11, align 4
   %12 = getelementptr inbounds { ptr, ptr }, ptr %fat.ptr2, i32 0, i32 0
   store ptr @_Z15lambda.L15C26.0Ri, ptr %12, align 8
@@ -117,8 +114,8 @@ define private void @_Z15lambda.L12C20.0Ri(ptr noundef nonnull dereferenceable(8
   store ptr %0, ptr %captures, align 8
   store ptr %1, ptr %x, align 8
   %3 = load ptr, ptr %captures, align 8
-  %w = getelementptr inbounds %anon.captures.0, ptr %3, i32 0, i32 0
-  %z = getelementptr inbounds %anon.captures.0, ptr %3, i32 0, i32 1
+  %w = getelementptr inbounds { i32, i32 }, ptr %3, i32 0, i32 0
+  %z = getelementptr inbounds { i32, i32 }, ptr %3, i32 0, i32 1
   %4 = load i32, ptr %w, align 4
   %5 = load i32, ptr %z, align 4
   %6 = add i32 %5, %4
@@ -136,8 +133,8 @@ define private i1 @_Z15lambda.L15C26.0Ri(ptr noundef nonnull dereferenceable(8)
   store ptr %0, ptr %captures, align 8
   store ptr %1, ptr %x, align 8
   %3 = load ptr, ptr %captures, align 8
-  %w = getelementptr inbounds %anon.captures.0.0, ptr %3, i32 0, i32 0
-  %z = getelementptr inbounds %anon.captures.0.0, ptr %3, i32 0, i32 1
+  %w = getelementptr inbounds { i32, i32 }, ptr %3, i32 0, i32 0
+  %z = getelementptr inbounds { i32, i32 }, ptr %3, i32 0, i32 1
   %4 = load i32, ptr %w, align 4
   %5 = load i32, ptr %z, align 4
   %6 = add i32 %5, %4
diff --git a/test/test-files/irgenerator/lambdas/success-multiple-visits/ir-code.ll b/test/test-files/irgenerator/lambdas/success-multiple-visits/ir-code.ll
index 7de2ca2dd..6f2876fb6 100644
--- a/test/test-files/irgenerator/lambdas/success-multiple-visits/ir-code.ll
+++ b/test/test-files/irgenerator/lambdas/success-multiple-visits/ir-code.ll
@@ -3,25 +3,22 @@ source_filename = "source.spice"
 target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-w64-windows-gnu"
 
-%anon.captures.0 = type { i32, i32 }
-%anon.captures.0.0 = type { i32, i32 }
-
 @printf.str.0 = private unnamed_addr constant [8 x i8] c"%d, %d\0A\00", align 1
 @printf.str.1 = private unnamed_addr constant [8 x i8] c"%d, %d\0A\00", align 1
 
 define private void @_Z4testv() {
   %t = alloca i32, align 4
   %x = alloca i32, align 4
-  %captures = alloca %anon.captures.0, align 8
+  %captures = alloca { i32, i32 }, align 8
   %fat.ptr = alloca { ptr, ptr }, align 8
   %l = alloca { ptr, ptr }, align 8
   store i32 123, ptr %t, align 4
   store i32 456, ptr %x, align 4
   %1 = load i32, ptr %t, align 4
-  %2 = getelementptr inbounds %anon.captures.0, ptr %captures, i32 0, i32 0
+  %2 = getelementptr inbounds { i32, i32 }, ptr %captures, i32 0, i32 0
   store i32 %1, ptr %2, align 4
   %3 = load i32, ptr %x, align 4
-  %4 = getelementptr inbounds %anon.captures.0, ptr %captures, i32 0, i32 1
+  %4 = getelementptr inbounds { i32, i32 }, ptr %captures, i32 0, i32 1
   store i32 %3, ptr %4, align 4
   %5 = getelementptr inbounds { ptr, ptr }, ptr %fat.ptr, i32 0, i32 0
   store ptr @_Z14lambda.L3C13.0v, ptr %5, align 8
@@ -41,8 +38,8 @@ define private void @_Z14lambda.L3C13.0v(ptr noundef nonnull dereferenceable(8)
   %captures = alloca ptr, align 8
   store ptr %0, ptr %captures, align 8
   %2 = load ptr, ptr %captures, align 8
-  %t = getelementptr inbounds %anon.captures.0, ptr %2, i32 0, i32 0
-  %x = getelementptr inbounds %anon.captures.0, ptr %2, i32 0, i32 1
+  %t = getelementptr inbounds { i32, i32 }, ptr %2, i32 0, i32 0
+  %x = getelementptr inbounds { i32, i32 }, ptr %2, i32 0, i32 1
   %3 = load i32, ptr %x, align 4
   %4 = load i32, ptr %t, align 4
   %5 = call i32 (ptr, ...) @printf(ptr noundef @printf.str.0, i32 %3, i32 %4)
@@ -55,16 +52,16 @@ declare noundef i32 @printf(ptr nocapture noundef readonly, ...) #0
 define private void @_Z4testi(i32 %0) {
   %t = alloca i32, align 4
   %x = alloca i32, align 4
-  %captures = alloca %anon.captures.0.0, align 8
+  %captures = alloca { i32, i32 }, align 8
   %fat.ptr = alloca { ptr, ptr }, align 8
   %l = alloca { ptr, ptr }, align 8
   store i32 %0, ptr %t, align 4
   store i32 456, ptr %x, align 4
   %2 = load i32, ptr %t, align 4
-  %3 = getelementptr inbounds %anon.captures.0.0, ptr %captures, i32 0, i32 0
+  %3 = getelementptr inbounds { i32, i32 }, ptr %captures, i32 0, i32 0
   store i32 %2, ptr %3, align 4
   %4 = load i32, ptr %x, align 4
-  %5 = getelementptr inbounds %anon.captures.0.0, ptr %captures, i32 0, i32 1
+  %5 = getelementptr inbounds { i32, i32 }, ptr %captures, i32 0, i32 1
   store i32 %4, ptr %5, align 4
   %6 = getelementptr inbounds { ptr, ptr }, ptr %fat.ptr, i32 0, i32 0
   store ptr @_Z14lambda.L3C13.1v, ptr %6, align 8
@@ -84,8 +81,8 @@ define private void @_Z14lambda.L3C13.1v(ptr noundef nonnull dereferenceable(8)
   %captures = alloca ptr, align 8
   store ptr %0, ptr %captures, align 8
   %2 = load ptr, ptr %captures, align 8
-  %t = getelementptr inbounds %anon.captures.0.0, ptr %2, i32 0, i32 0
-  %x = getelementptr inbounds %anon.captures.0.0, ptr %2, i32 0, i32 1
+  %t = getelementptr inbounds { i32, i32 }, ptr %2, i32 0, i32 0
+  %x = getelementptr inbounds { i32, i32 }, ptr %2, i32 0, i32 1
   %3 = load i32, ptr %x, align 4
   %4 = load i32, ptr %t, align 4
   %5 = call i32 (ptr, ...) @printf(ptr noundef @printf.str.1, i32 %3, i32 %4)
diff --git a/test/test-files/std/type/bool-type-functions/source.spice b/test/test-files/std/type/bool-type-functions/source.spice
index 3fabe7f69..f9e8e840d 100644
--- a/test/test-files/std/type/bool-type-functions/source.spice
+++ b/test/test-files/std/type/bool-type-functions/source.spice
@@ -32,10 +32,10 @@ f<int> main() {
     assert asByte2 == (byte) 0;
 
     // toString()
-    //string asString1 = toString(true);
-    //assert asString1 == "true";
-    //string asString2 = toString(false);
-    //assert asString2 == "false";
+    string asString1 = toString(true);
+    assert asString1 == "true";
+    string asString2 = toString(false);
+    assert asString2 == "false";
 
     printf("All assertions succeeded");
 }
\ No newline at end of file
diff --git a/test/test-files/std/type/byte-type-functions/source.spice b/test/test-files/std/type/byte-type-functions/source.spice
index 769b1dda2..0e1da2b2e 100644
--- a/test/test-files/std/type/byte-type-functions/source.spice
+++ b/test/test-files/std/type/byte-type-functions/source.spice
@@ -18,8 +18,8 @@ f<int> main() {
     assert asLong == 63l;
 
     // toString()
-    //string asString = toString((byte) 13);
-    //assert asString == "13";
+    String asString = toString((byte) 13);
+    assert asString.getRaw() == "13";
 
     // toBool()
     bool asBool1 = toBool((byte) 1);
diff --git a/test/test-files/std/type/char-type-functions/source.spice b/test/test-files/std/type/char-type-functions/source.spice
index 71ddb4e67..ca3b31886 100644
--- a/test/test-files/std/type/char-type-functions/source.spice
+++ b/test/test-files/std/type/char-type-functions/source.spice
@@ -18,8 +18,8 @@ f<int> main() {
     assert asLong == 75l;
 
     // toString()
-    //string asString = toString('v');
-    //assert asString == "v";
+    String asString = toString('v');
+    assert asString.getRaw() == "v";
 
     // toBool()
     bool asBool1 = toBool('1');
diff --git a/test/test-files/std/type/double-type-functions/source.spice b/test/test-files/std/type/double-type-functions/source.spice
index 02a366872..e05c1fc85 100644
--- a/test/test-files/std/type/double-type-functions/source.spice
+++ b/test/test-files/std/type/double-type-functions/source.spice
@@ -2,24 +2,20 @@ import "std/type/double";
 
 f<int> main() {
     // toInt()
-    //int asInt = toInt(123.54);
-    //assert asInt == 123;
+    int asInt = toInt(123.54);
+    assert asInt == 123;
 
     // toShort()
-    //short asShort = toShort(12.345);
-    //assert asShort == 12;
+    short asShort = toShort(12.345);
+    assert asShort == 12;
 
     // toLong()
-    //long asLong = toLong(534569.2345);
-    //assert asLong == 534569l;
-
-    // toByte()
-    //long asByte = toLong(53.89);
-    //assert asByte == (byte) 53;
+    long asLong = toLong(534569.2345);
+    assert asLong == 534569l;
 
     // toString()
-    //string asString = toString(9.0);
-    //assert asString == "9.0";
+    //String asString = toString(3.14);
+    //assert asString.getRaw() == "3.14";
 
     // toBool()
     bool asBool1 = toBool(1.0);
diff --git a/test/test-files/std/type/int-type-functions/source.spice b/test/test-files/std/type/int-type-functions/source.spice
index 3cefc4750..81b01c016 100644
--- a/test/test-files/std/type/int-type-functions/source.spice
+++ b/test/test-files/std/type/int-type-functions/source.spice
@@ -22,9 +22,8 @@ f<int> main() {
     assert asChar == 'B';
 
     // toString()
-    //string asString = toString(12345);
-    //assert asString == "12345";
-    //printf("Str: %s\n", asString);
+    String asString = toString(12345);
+    assert asString.getRaw() == "12345";
 
     // toBool()
     bool asBool1 = toBool(1);
diff --git a/test/test-files/std/type/long-type-functions/source.spice b/test/test-files/std/type/long-type-functions/source.spice
index 346aae05f..5d952e20f 100644
--- a/test/test-files/std/type/long-type-functions/source.spice
+++ b/test/test-files/std/type/long-type-functions/source.spice
@@ -22,9 +22,8 @@ f<int> main() {
     assert asChar == 'B';
 
     // toString()
-    //string asString = toString(12345l);
-    //assert asString == "12345";
-    //printf("Str: %s\n", asString);
+    String asString = toString(12345l);
+    assert asString.getRaw() == "12345";
 
     // toBool()
     bool asBool1 = toBool(1l);
diff --git a/test/test-files/std/type/short-type-functions/source.spice b/test/test-files/std/type/short-type-functions/source.spice
index d00de422f..65c227566 100644
--- a/test/test-files/std/type/short-type-functions/source.spice
+++ b/test/test-files/std/type/short-type-functions/source.spice
@@ -22,9 +22,8 @@ f<int> main() {
     assert asChar == 'B';
 
     // toString()
-    //string asString = toString(15);
-    //assert asString == "15";
-    //printf("Str: %s\n", asString);
+    String asString = toString(15s);
+    assert asString.getRaw() == "15";
 
     // toBool()
     bool asBool1 = toBool(1s);
diff --git a/test/test-files/std/type/string-type-functions/source.spice b/test/test-files/std/type/string-type-functions/source.spice
index cd51aa97e..f8a3acce3 100644
--- a/test/test-files/std/type/string-type-functions/source.spice
+++ b/test/test-files/std/type/string-type-functions/source.spice
@@ -3,32 +3,27 @@ import "std/type/string";
 f<int> main() {
     // toDouble()
     double asDouble = toDouble("5.67");
-    //assert asDouble == 5.67;
+    assert asDouble == 5.67;
 
     // toInt()
     int asInt = toInt("-6546");
-    //assert asInt == -6546;
+    assert asInt == -6546;
 
     // toLong()
     long asLong = toLong("56");
-    //assert asLong == 56l;
+    assert asLong == 56l;
 
     // toShort()
     short asShort = toShort("-12");
-    //assert asShort == -12s;
+    assert asShort == -12s;
 
     // toByte()
     byte asByte = toByte("12");
-    //assert asByte == (byte) 12;
+    assert asByte == (byte) 12;
 
     // toChar()
     char asChar = toChar("i");
-    //assert asChar == 'i';
-
-    // toString()
-    //string asString = toString(15);
-    //assert asString == "15";
-    //printf("Str: %s\n", asString);
+    assert asChar == 'i';
 
     // toBool()
     bool asBool1 = toBool("true");
diff --git a/test/test-files/typechecker/foreach-loops/success-foreach-item-type-inference/symbol-table.json b/test/test-files/typechecker/foreach-loops/success-foreach-item-type-inference/symbol-table.json
index bad3f223c..b60928600 100644
--- a/test/test-files/typechecker/foreach-loops/success-foreach-item-type-inference/symbol-table.json
+++ b/test/test-files/typechecker/foreach-loops/success-foreach-item-type-inference/symbol-table.json
@@ -336,7 +336,7 @@
           "name": "this.Iterable",
           "orderIndex": 0,
           "state": "declared",
-          "type": "public std/iterator/iterable::Iterable<T>"
+          "type": "public std/iterator/iterable::Iterable<short>"
         }
       ]
     },
@@ -565,7 +565,7 @@
           "name": "this.Iterable",
           "orderIndex": 0,
           "state": "declared",
-          "type": "public std/iterator/iterable::Iterable<T>"
+          "type": "public std/iterator/iterable::Iterable<short>"
         }
       ]
     }
diff --git a/test/test-files/typechecker/methods/error-method-on-field-without-this/exception.out b/test/test-files/typechecker/methods/error-method-on-field-without-this/exception.out
new file mode 100644
index 000000000..429508bcc
--- /dev/null
+++ b/test/test-files/typechecker/methods/error-method-on-field-without-this/exception.out
@@ -0,0 +1,8 @@
+[Error|Compiler]:
+Unresolved soft errors: There are unresolved errors. Please fix them and recompile.
+
+[Error|Semantic] ./test-files/typechecker/methods/error-method-on-field-without-this/source.spice:12:5:
+Referenced undefined variable: The symbol 'a' could not be found. Missing 'this.' prefix?
+
+12  a.foo();
+    ^^^^^^^
\ No newline at end of file
diff --git a/test/test-files/typechecker/methods/error-method-on-field-without-this/source.spice b/test/test-files/typechecker/methods/error-method-on-field-without-this/source.spice
new file mode 100644
index 000000000..fe7fa3259
--- /dev/null
+++ b/test/test-files/typechecker/methods/error-method-on-field-without-this/source.spice
@@ -0,0 +1,18 @@
+type A struct {}
+
+p A.foo() {
+    printf("A.foo\n");
+}
+
+type B struct {
+    A a
+}
+
+p B.callFooOnA() {
+    a.foo();
+}
+
+f<int> main() {
+    B b;
+    b.callFooOnA();
+}
\ No newline at end of file