...

.vscode/settings.json

@@ -0,0 +1,5 @@
+{
+    "files.associations": {
+        "ref.h": "c"
+    }
+}

compiler/NubLang.CLI/Program.cs

@@ -21,7 +21,7 @@ foreach (var file in args)
 }
 
 var modules = Module.Collect(syntaxTrees);
-var compilationUnits = new List<CompilationUnit?>();
+var compilationUnits = new List<List<TopLevelNode>>();
 
 for (var i = 0; i < args.Length; i++)
 {
@@ -46,16 +46,48 @@ var cPaths = new List<string>();
 
 Directory.CreateDirectory(".build");
 
+var typedModules = modules.Select(x => (x.Key, TypedModule.FromModule(x.Key, x.Value, modules))).ToDictionary();
+
+var moduleHeaders = new List<string>();
+
+var commonHeaderOut = Path.Combine(".build", "runtime.h");
+
+File.WriteAllText(commonHeaderOut, """
+                                   #include <stddef.h>
+
+                                   void *rc_alloc(size_t size, void (*destructor)(void *self));
+                                   void rc_retain(void *obj);
+                                   void rc_release(void *obj);
+
+                                   typedef struct
+                                   {
+                                       unsigned long long length;
+                                       char *data;
+                                   } nub_string;
+
+                                   typedef struct
+                                   {
+                                       unsigned long long length;
+                                       void *data;
+                                   } nub_slice;
+                                   """);
+
+moduleHeaders.Add(commonHeaderOut);
+
+foreach (var typedModule in typedModules)
+{
+    var header = HeaderGenerator.Generate(typedModule.Key, typedModule.Value);
+    var headerOut = Path.Combine(".build", "modules", typedModule.Key + ".h");
+    Directory.CreateDirectory(Path.Combine(".build", "modules"));
+    File.WriteAllText(headerOut, header);
+    moduleHeaders.Add(headerOut);
+}
+
 for (var i = 0; i < args.Length; i++)
 {
     var file = args[i];
     var compilationUnit = compilationUnits[i];
 
-    if (compilationUnit == null)
-    {
-        continue;
-    }
-
     var generator = new Generator(compilationUnit);
     var directory = Path.GetDirectoryName(file);
     if (!string.IsNullOrWhiteSpace(directory))
@@ -74,6 +106,7 @@ foreach (var cPath in cPaths)
 {
     var objectPath = Path.ChangeExtension(cPath, "o");
     using var compileProcess = Process.Start("clang", [
+        ..moduleHeaders.SelectMany(x => new[] { "-include", x }),
         "-ffreestanding", "-std=c23",
         "-g", "-c",
         "-o", objectPath,

compiler/NubLang.LSP/AstExtensions.cs

@@ -1,5 +1,4 @@
 using NubLang.Ast;
-using NubLang.Syntax;
 using OmniSharp.Extensions.LanguageServer.Protocol.Models;
 using Range = OmniSharp.Extensions.LanguageServer.Protocol.Models.Range;
 
@@ -58,16 +57,16 @@ public static class AstExtensions
         return false;
     }
 
-    public static FuncNode? FunctionAtPosition(this CompilationUnit compilationUnit, int line, int character)
+    public static FuncNode? FunctionAtPosition(this List<TopLevelNode> compilationUnit, int line, int character)
     {
         return compilationUnit
-            .Functions
+            .OfType<FuncNode>()
             .FirstOrDefault(x => x.ContainsPosition(line, character));
     }
 
-    public static Node? DeepestNodeAtPosition(this CompilationUnit compilationUnit, int line, int character)
+    public static Node? DeepestNodeAtPosition(this List<TopLevelNode> compilationUnit, int line, int character)
     {
-        return compilationUnit.Functions
+        return compilationUnit
             .SelectMany(x => x.DescendantsAndSelf())
             .Where(n => n.ContainsPosition(line, character))
             .OrderBy(n => n.Tokens.First().Span.Start.Line)

compiler/NubLang.LSP/CompletionHandler.cs

@@ -118,30 +118,30 @@ internal class CompletionHandler(WorkspaceManager workspaceManager) : Completion
         var compilationUnit = workspaceManager.GetCompilationUnit(uri);
         if (compilationUnit != null)
         {
-            var function = compilationUnit.Functions.FirstOrDefault(x => x.Body != null && x.Body.ContainsPosition(position.Line, position.Character));
+            var function = compilationUnit.OfType<FuncNode>().FirstOrDefault(x => x.Body != null && x.Body.ContainsPosition(position.Line, position.Character));
             if (function != null)
             {
                 completions.AddRange(_statementSnippets);
 
-                foreach (var (module, prototypes) in compilationUnit.ImportedFunctions)
+                // foreach (var (module, prototypes) in compilationUnit.ImportedFunctions)
-                {
+                // {
-                    foreach (var prototype in prototypes)
+                //     foreach (var prototype in prototypes)
-                    {
+                //     {
-                        var parameterStrings = new List<string>();
+                //         var parameterStrings = new List<string>();
-                        foreach (var (index, parameter) in prototype.Parameters.Index())
+                //         foreach (var (index, parameter) in prototype.Parameters.Index())
-                        {
+                //         {
-                            parameterStrings.AddRange($"${{{index + 1}:{parameter.NameToken.Value}}}");
+                //             parameterStrings.AddRange($"${{{index + 1}:{parameter.NameToken.Value}}}");
-                        }
+                //         }
-
+                //
-                        completions.Add(new CompletionItem
+                //         completions.Add(new CompletionItem
-                        {
+                //         {
-                            Kind = CompletionItemKind.Function,
+                //             Kind = CompletionItemKind.Function,
-                            Label = $"{module.Value}::{prototype.NameToken.Value}",
+                //             Label = $"{module.Value}::{prototype.NameToken.Value}",
-                            InsertTextFormat = InsertTextFormat.Snippet,
+                //             InsertTextFormat = InsertTextFormat.Snippet,
-                            InsertText = $"{module.Value}::{prototype.NameToken.Value}({string.Join(", ", parameterStrings)})",
+                //             InsertText = $"{module.Value}::{prototype.NameToken.Value}({string.Join(", ", parameterStrings)})",
-                        });
+                //         });
-                    }
+                //     }
-                }
+                // }
 
                 foreach (var parameter in function.Prototype.Parameters)
                 {

compiler/NubLang.LSP/DefinitionHandler.cs

@@ -57,15 +57,16 @@ internal class DefinitionHandler(WorkspaceManager workspaceManager) : Definition
             }
             case FuncIdentifierNode funcIdentifierNode:
             {
-                var prototype = compilationUnit.ImportedFunctions
+                // var prototype = compilationUnit
-                    .Where(x => x.Key.Value == funcIdentifierNode.ModuleToken.Value)
+                //     .ImportedFunctions
-                    .SelectMany(x => x.Value)
+                //     .Where(x => x.Key.Value == funcIdentifierNode.ModuleToken.Value)
-                    .FirstOrDefault(x => x.NameToken.Value == funcIdentifierNode.NameToken.Value);
+                //     .SelectMany(x => x.Value)
-
+                //     .FirstOrDefault(x => x.NameToken.Value == funcIdentifierNode.NameToken.Value);
-                if (prototype != null)
+                //
-                {
+                // if (prototype != null)
-                    return new LocationOrLocationLinks(prototype.ToLocation());
+                // {
-                }
+                //     return new LocationOrLocationLinks(prototype.ToLocation());
+                // }
 
                 return null;
             }

compiler/NubLang.LSP/HoverHandler.cs

@@ -39,108 +39,110 @@ internal class HoverHandler(WorkspaceManager workspaceManager) : HoverHandlerBas
             return null;
         }
 
-        var message = CreateMessage(hoveredNode, compilationUnit);
+        // var message = CreateMessage(hoveredNode, compilationUnit);
-        if (message == null)
+        // if (message == null)
-        {
+        // {
+        //     return null;
+        // }
+        //
+        // return new Hover
+        // {
+        //     Contents = new MarkedStringsOrMarkupContent(new MarkupContent
+        //     {
+        //         Value = message,
+        //         Kind = MarkupKind.Markdown,
+        //     })
+        // };
+
         return null;
     }
 
-        return new Hover
+//     private static string? CreateMessage(Node hoveredNode, CompilationUnit compilationUnit)
-        {
+//     {
-            Contents = new MarkedStringsOrMarkupContent(new MarkupContent
+//         return hoveredNode switch
-            {
+//         {
-                Value = message,
+//             FuncNode funcNode => CreateFuncPrototypeMessage(funcNode.Prototype),
-                Kind = MarkupKind.Markdown,
+//             FuncPrototypeNode funcPrototypeNode => CreateFuncPrototypeMessage(funcPrototypeNode),
-            })
+//             FuncIdentifierNode funcIdentifierNode => CreateFuncIdentifierMessage(funcIdentifierNode, compilationUnit),
-        };
+//             FuncParameterNode funcParameterNode => CreateTypeNameMessage("Function parameter", funcParameterNode.NameToken.Value, funcParameterNode.Type),
-    }
+//             VariableIdentifierNode variableIdentifierNode => CreateTypeNameMessage("Variable", variableIdentifierNode.NameToken.Value, variableIdentifierNode.Type),
-
+//             VariableDeclarationNode variableDeclarationNode => CreateTypeNameMessage("Variable declaration", variableDeclarationNode.NameToken.Value, variableDeclarationNode.Type),
-    private static string? CreateMessage(Node hoveredNode, CompilationUnit compilationUnit)
+//             StructFieldAccessNode structFieldAccessNode => CreateTypeNameMessage("Struct field", $"{structFieldAccessNode.Target.Type}.{structFieldAccessNode.FieldToken.Value}", structFieldAccessNode.Type),
-    {
+//             CStringLiteralNode cStringLiteralNode => CreateLiteralMessage(cStringLiteralNode.Type, '"' + cStringLiteralNode.Value + '"'),
-        return hoveredNode switch
+//             StringLiteralNode stringLiteralNode => CreateLiteralMessage(stringLiteralNode.Type, '"' + stringLiteralNode.Value + '"'),
-        {
+//             BoolLiteralNode boolLiteralNode => CreateLiteralMessage(boolLiteralNode.Type, boolLiteralNode.Value.ToString()),
-            FuncNode funcNode => CreateFuncPrototypeMessage(funcNode.Prototype),
+//             Float32LiteralNode float32LiteralNode => CreateLiteralMessage(float32LiteralNode.Type, float32LiteralNode.Value.ToString(CultureInfo.InvariantCulture)),
-            FuncPrototypeNode funcPrototypeNode => CreateFuncPrototypeMessage(funcPrototypeNode),
+//             Float64LiteralNode float64LiteralNode => CreateLiteralMessage(float64LiteralNode.Type, float64LiteralNode.Value.ToString(CultureInfo.InvariantCulture)),
-            FuncIdentifierNode funcIdentifierNode => CreateFuncIdentifierMessage(funcIdentifierNode, compilationUnit),
+//             I8LiteralNode i8LiteralNode => CreateLiteralMessage(i8LiteralNode.Type, i8LiteralNode.Value.ToString()),
-            FuncParameterNode funcParameterNode => CreateTypeNameMessage("Function parameter", funcParameterNode.NameToken.Value, funcParameterNode.Type),
+//             I16LiteralNode i16LiteralNode => CreateLiteralMessage(i16LiteralNode.Type, i16LiteralNode.Value.ToString()),
-            VariableIdentifierNode variableIdentifierNode => CreateTypeNameMessage("Variable", variableIdentifierNode.NameToken.Value, variableIdentifierNode.Type),
+//             I32LiteralNode i32LiteralNode => CreateLiteralMessage(i32LiteralNode.Type, i32LiteralNode.Value.ToString()),
-            VariableDeclarationNode variableDeclarationNode => CreateTypeNameMessage("Variable declaration", variableDeclarationNode.NameToken.Value, variableDeclarationNode.Type),
+//             I64LiteralNode i64LiteralNode => CreateLiteralMessage(i64LiteralNode.Type, i64LiteralNode.Value.ToString()),
-            StructFieldAccessNode structFieldAccessNode => CreateTypeNameMessage("Struct field", $"{structFieldAccessNode.Target.Type}.{structFieldAccessNode.FieldToken.Value}", structFieldAccessNode.Type),
+//             U8LiteralNode u8LiteralNode => CreateLiteralMessage(u8LiteralNode.Type, u8LiteralNode.Value.ToString()),
-            CStringLiteralNode cStringLiteralNode => CreateLiteralMessage(cStringLiteralNode.Type, '"' + cStringLiteralNode.Value + '"'),
+//             U16LiteralNode u16LiteralNode => CreateLiteralMessage(u16LiteralNode.Type, u16LiteralNode.Value.ToString()),
-            StringLiteralNode stringLiteralNode => CreateLiteralMessage(stringLiteralNode.Type, '"' + stringLiteralNode.Value + '"'),
+//             U32LiteralNode u32LiteralNode => CreateLiteralMessage(u32LiteralNode.Type, u32LiteralNode.Value.ToString()),
-            BoolLiteralNode boolLiteralNode => CreateLiteralMessage(boolLiteralNode.Type, boolLiteralNode.Value.ToString()),
+//             U64LiteralNode u64LiteralNode => CreateLiteralMessage(u64LiteralNode.Type, u64LiteralNode.Value.ToString()),
-            Float32LiteralNode float32LiteralNode => CreateLiteralMessage(float32LiteralNode.Type, float32LiteralNode.Value.ToString(CultureInfo.InvariantCulture)),
+//             // Expressions can have a generic fallback showing the resulting type
-            Float64LiteralNode float64LiteralNode => CreateLiteralMessage(float64LiteralNode.Type, float64LiteralNode.Value.ToString(CultureInfo.InvariantCulture)),
+//             ExpressionNode expressionNode => $"""
-            I8LiteralNode i8LiteralNode => CreateLiteralMessage(i8LiteralNode.Type, i8LiteralNode.Value.ToString()),
+//                                               **Expression** `{expressionNode.GetType().Name}`
-            I16LiteralNode i16LiteralNode => CreateLiteralMessage(i16LiteralNode.Type, i16LiteralNode.Value.ToString()),
+//                                               ```nub
-            I32LiteralNode i32LiteralNode => CreateLiteralMessage(i32LiteralNode.Type, i32LiteralNode.Value.ToString()),
+//                                               {expressionNode.Type}
-            I64LiteralNode i64LiteralNode => CreateLiteralMessage(i64LiteralNode.Type, i64LiteralNode.Value.ToString()),
+//                                               ```
-            U8LiteralNode u8LiteralNode => CreateLiteralMessage(u8LiteralNode.Type, u8LiteralNode.Value.ToString()),
+//                                               """,
-            U16LiteralNode u16LiteralNode => CreateLiteralMessage(u16LiteralNode.Type, u16LiteralNode.Value.ToString()),
+//             BlockNode => null,
-            U32LiteralNode u32LiteralNode => CreateLiteralMessage(u32LiteralNode.Type, u32LiteralNode.Value.ToString()),
+//             _ => hoveredNode.GetType().Name
-            U64LiteralNode u64LiteralNode => CreateLiteralMessage(u64LiteralNode.Type, u64LiteralNode.Value.ToString()),
+//         };
-            // Expressions can have a generic fallback showing the resulting type
+//     }
-            ExpressionNode expressionNode => $"""
+//
-                                              **Expression** `{expressionNode.GetType().Name}`
+//     private static string CreateLiteralMessage(NubType type, string value)
-                                              ```nub
+//     {
-                                              {expressionNode.Type}
+//         return $"""
-                                              ```
+//                 **Literal** `{type}`
-                                              """,
+//                 ```nub
-            BlockNode => null,
+//                 {value}: {type}
-            _ => hoveredNode.GetType().Name
+//                 ```
-        };
+//                 """;
-    }
+//     }
-
+//
-    private static string CreateLiteralMessage(NubType type, string value)
+//     private static string CreateTypeNameMessage(string description, string name, NubType type)
-    {
+//     {
-        return $"""
+//         return $"""
-                **Literal** `{type}`
+//                 **{description}** `{name}`
-                ```nub
+//                 ```nub
-                {value}: {type}
+//                 {name}: {type}
-                ```
+//                 ```
-                """;
+//                 """;
-    }
+//     }
-
+//
-    private static string CreateTypeNameMessage(string description, string name, NubType type)
+//     private static string CreateFuncIdentifierMessage(FuncIdentifierNode funcIdentifierNode, CompilationUnit compilationUnit)
-    {
+//     {
-        return $"""
+//         var func = compilationUnit.ImportedFunctions
-                **{description}** `{name}`
+//             .Where(x => x.Key.Value == funcIdentifierNode.ModuleToken.Value)
-                ```nub
+//             .SelectMany(x => x.Value)
-                {name}: {type}
+//             .FirstOrDefault(x => x.NameToken.Value == funcIdentifierNode.NameToken.Value);
-                ```
+//
-                """;
+//         if (func == null)
-    }
+//         {
-
+//             return $"""
-    private static string CreateFuncIdentifierMessage(FuncIdentifierNode funcIdentifierNode, CompilationUnit compilationUnit)
+//                     **Function** `{funcIdentifierNode.ModuleToken.Value}::{funcIdentifierNode.NameToken.Value}`
-    {
+//                     ```nub
-        var func = compilationUnit.ImportedFunctions
+//                     // Declaration not found
-            .Where(x => x.Key.Value == funcIdentifierNode.ModuleToken.Value)
+//                     ```
-            .SelectMany(x => x.Value)
+//                     """;
-            .FirstOrDefault(x => x.NameToken.Value == funcIdentifierNode.NameToken.Value);
+//         }
-
+//
-        if (func == null)
+//         return CreateFuncPrototypeMessage(func);
-        {
+//     }
-            return $"""
+//
-                    **Function** `{funcIdentifierNode.ModuleToken.Value}::{funcIdentifierNode.NameToken.Value}`
+//     private static string CreateFuncPrototypeMessage(FuncPrototypeNode funcPrototypeNode)
-                    ```nub
+//     {
-                    // Declaration not found
+//         var parameterText = string.Join(", ", funcPrototypeNode.Parameters.Select(x => $"{x.NameToken.Value}: {x.Type}"));
-                    ```
+//         var externText = funcPrototypeNode.ExternSymbolToken != null ? $"extern \"{funcPrototypeNode.ExternSymbolToken.Value}\" " : "";
-                    """;
+//
-        }
+//         return $"""
-
+//                 **Function** `{funcPrototypeNode.NameToken.Value}`
-        return CreateFuncPrototypeMessage(func);
+//                 ```nub
-    }
+//                 {externText}func {funcPrototypeNode.NameToken.Value}({parameterText}): {funcPrototypeNode.ReturnType}
-
+//                 ```
-    private static string CreateFuncPrototypeMessage(FuncPrototypeNode funcPrototypeNode)
+//                 """;
-    {
+//     }
-        var parameterText = string.Join(", ", funcPrototypeNode.Parameters.Select(x => $"{x.NameToken.Value}: {x.Type}"));
-        var externText = funcPrototypeNode.ExternSymbolToken != null ? $"extern \"{funcPrototypeNode.ExternSymbolToken.Value}\" " : "";
-
-        return $"""
-                **Function** `{funcPrototypeNode.NameToken.Value}`
-                ```nub
-                {externText}func {funcPrototypeNode.NameToken.Value}({parameterText}): {funcPrototypeNode.ReturnType}
-                ```
-                """;
-    }
 }

compiler/NubLang.LSP/WorkspaceManager.cs

@@ -7,7 +7,7 @@ namespace NubLang.LSP;
 public class WorkspaceManager(DiagnosticsPublisher diagnosticsPublisher)
 {
     private readonly Dictionary<string, SyntaxTree> _syntaxTrees = new();
-    private readonly Dictionary<string, CompilationUnit> _compilationUnits = new();
+    private readonly Dictionary<string, List<TopLevelNode>> _compilationUnits = new();
 
     public void Init(string rootPath)
     {
@@ -35,16 +35,9 @@ public class WorkspaceManager(DiagnosticsPublisher diagnosticsPublisher)
             var result = typeChecker.Check();
             diagnosticsPublisher.Publish(fsPath, typeChecker.Diagnostics);
 
-            if (result == null)
-            {
-                _compilationUnits.Remove(fsPath);
-            }
-            else
-            {
             _compilationUnits[fsPath] = result;
         }
     }
-    }
 
     public void UpdateFile(DocumentUri path)
     {
@@ -66,15 +59,8 @@ public class WorkspaceManager(DiagnosticsPublisher diagnosticsPublisher)
         var result = typeChecker.Check();
         diagnosticsPublisher.Publish(fsPath, typeChecker.Diagnostics);
 
-        if (result == null)
-        {
-            _compilationUnits.Remove(fsPath);
-        }
-        else
-        {
         _compilationUnits[fsPath] = result;
     }
-    }
 
     public void RemoveFile(DocumentUri path)
     {
@@ -83,7 +69,7 @@ public class WorkspaceManager(DiagnosticsPublisher diagnosticsPublisher)
         _compilationUnits.Remove(fsPath);
     }
 
-    public CompilationUnit? GetCompilationUnit(DocumentUri path)
+    public List<TopLevelNode>? GetCompilationUnit(DocumentUri path)
     {
         return _compilationUnits.GetValueOrDefault(path.GetFileSystemPath());
     }

compiler/NubLang/Ast/CompilationUnit.cs

@@ -2,10 +2,11 @@ using NubLang.Syntax;
 
 namespace NubLang.Ast;
 
-public sealed class CompilationUnit(IdentifierToken module, List<FuncNode> functions, Dictionary<IdentifierToken, List<NubStructType>> importedStructTypes, Dictionary<IdentifierToken, List<FuncPrototypeNode>> importedFunctions)
+// public sealed class CompilationUnit(IdentifierToken module, List<FuncNode> functions, List<StructNode> structTypes, Dictionary<IdentifierToken, List<NubStructType>> importedStructTypes, Dictionary<IdentifierToken, List<FuncPrototypeNode>> importedFunctions)
-{
+// {
-    public IdentifierToken Module { get; } = module;
+//     public IdentifierToken Module { get; } = module;
-    public List<FuncNode> Functions { get; } = functions;
+//     public List<FuncNode> Functions { get; } = functions;
-    public Dictionary<IdentifierToken, List<NubStructType>> ImportedStructTypes { get; } = importedStructTypes;
+//     public List<StructNode> Structs { get; } = structTypes;
-    public Dictionary<IdentifierToken, List<FuncPrototypeNode>> ImportedFunctions { get; } = importedFunctions;
+//     public Dictionary<IdentifierToken, List<NubStructType>> ImportedStructTypes { get; } = importedStructTypes;
-}
+//     public Dictionary<IdentifierToken, List<FuncPrototypeNode>> ImportedFunctions { get; } = importedFunctions;
+// }

compiler/NubLang/Ast/Node.cs

@@ -29,9 +29,31 @@ public abstract class Node(List<Token> tokens)
     }
 }
 
+public abstract class TopLevelNode(List<Token> tokens) : Node(tokens);
+
+public class ImportNode(List<Token> tokens, IdentifierToken nameToken) : TopLevelNode(tokens)
+{
+    public IdentifierToken NameToken { get; } = nameToken;
+
+    public override IEnumerable<Node> Children()
+    {
+        return [];
+    }
+}
+
+public class ModuleNode(List<Token> tokens, IdentifierToken nameToken) : TopLevelNode(tokens)
+{
+    public IdentifierToken NameToken { get; } = nameToken;
+
+    public override IEnumerable<Node> Children()
+    {
+        return [];
+    }
+}
+
 #region Definitions
 
-public abstract class DefinitionNode(List<Token> tokens, IdentifierToken nameToken) : Node(tokens)
+public abstract class DefinitionNode(List<Token> tokens, IdentifierToken nameToken) : TopLevelNode(tokens)
 {
     public IdentifierToken NameToken { get; } = nameToken;
 }
@@ -75,6 +97,35 @@ public class FuncNode(List<Token> tokens, FuncPrototypeNode prototype, BlockNode
     }
 }
 
+public class StructFieldNode(List<Token> tokens, IdentifierToken nameToken, NubType type, ExpressionNode? value) : Node(tokens)
+{
+    public IdentifierToken NameToken { get; } = nameToken;
+    public NubType Type { get; } = type;
+    public ExpressionNode? Value { get; } = value;
+
+    public override IEnumerable<Node> Children()
+    {
+        if (Value != null)
+        {
+            yield return Value;
+        }
+    }
+}
+
+public class StructNode(List<Token> tokens, IdentifierToken name, NubStructType structType, List<StructFieldNode> fields) : DefinitionNode(tokens, name)
+{
+    public NubStructType StructType { get; } = structType;
+    public List<StructFieldNode> Fields { get; } = fields;
+
+    public override IEnumerable<Node> Children()
+    {
+        foreach (var field in Fields)
+        {
+            yield return field;
+        }
+    }
+}
+
 #endregion
 
 #region Statements
@@ -554,6 +605,16 @@ public class DereferenceNode(List<Token> tokens, NubType type, ExpressionNode ta
     }
 }
 
+public class RefDereferenceNode(List<Token> tokens, NubType type, ExpressionNode target) : LValueExpressionNode(tokens, type)
+{
+    public ExpressionNode Target { get; } = target;
+
+    public override IEnumerable<Node> Children()
+    {
+        yield return Target;
+    }
+}
+
 public class SizeNode(List<Token> tokens, NubType TargetType) : RValueExpressionNode(tokens, new NubIntType(false, 64))
 {
     public NubType TargetType { get; } = TargetType;
@@ -574,6 +635,19 @@ public class CastNode(List<Token> tokens, NubType type, ExpressionNode value) :
     }
 }
 
+public class RefStructInitializerNode(List<Token> tokens, NubType type, Dictionary<IdentifierToken, ExpressionNode> initializers) : RValueExpressionNode(tokens, type)
+{
+    public Dictionary<IdentifierToken, ExpressionNode> Initializers { get; } = initializers;
+
+    public override IEnumerable<Node> Children()
+    {
+        foreach (var initializer in Initializers)
+        {
+            yield return initializer.Value;
+        }
+    }
+}
+
 public class EnumReferenceIntermediateNode(List<Token> tokens, IdentifierToken moduleToken, IdentifierToken nameToken) : IntermediateExpression(tokens)
 {
     public IdentifierToken ModuleToken { get; } = moduleToken;

compiler/NubLang/Ast/NubType.cs

@@ -57,6 +57,15 @@ public sealed class NubPointerType(NubType baseType) : NubType
     public override int GetHashCode() => HashCode.Combine(typeof(NubPointerType), BaseType);
 }
 
+public class NubRefType(NubType baseType) : NubType
+{
+    public NubType BaseType { get; } = baseType;
+
+    public override string ToString() => "&" + BaseType;
+    public override bool Equals(NubType? other) => other is NubRefType;
+    public override int GetHashCode() => HashCode.Combine(typeof(NubRefType));
+}
+
 public class NubFuncType(List<NubType> parameters, NubType returnType) : NubType
 {
     public List<NubType> Parameters { get; } = parameters;

compiler/NubLang/Ast/TypeChecker.cs

@@ -10,8 +10,8 @@ public sealed class TypeChecker
     private readonly Dictionary<string, Module> _modules;
 
     private readonly Stack<Scope> _scopes = [];
-    private readonly Dictionary<(string Module, string Name), NubType> _typeCache = new();
+
-    private readonly HashSet<(string Module, string Name)> _resolvingTypes = [];
+    private readonly TypeResolver _typeResolver;
 
     private Scope Scope => _scopes.Peek();
 
@@ -21,19 +21,18 @@ public sealed class TypeChecker
     {
         _syntaxTree = syntaxTree;
         _modules = modules;
+        _typeResolver = new TypeResolver(_modules);
     }
 
-    public CompilationUnit? Check()
+    public List<TopLevelNode> Check()
     {
         _scopes.Clear();
-        _typeCache.Clear();
-        _resolvingTypes.Clear();
 
         var moduleDeclarations = _syntaxTree.TopLevelSyntaxNodes.OfType<ModuleSyntax>().ToList();
         if (moduleDeclarations.Count == 0)
         {
             Diagnostics.Add(Diagnostic.Error("Missing module declaration").WithHelp("module \"main\"").Build());
-            return null;
+            return [];
         }
 
         if (moduleDeclarations.Count > 1)
@@ -79,72 +78,45 @@ public sealed class TypeChecker
                     .At(last)
                     .Build());
 
-                return null;
+                return [];
             }
         }
 
-        var functions = new List<FuncNode>();
+        var topLevelNodes = new List<TopLevelNode>();
 
         using (BeginRootScope(moduleName))
         {
-            foreach (var funcSyntax in _syntaxTree.TopLevelSyntaxNodes.OfType<FuncSyntax>())
+            foreach (var topLevelSyntaxNode in _syntaxTree.TopLevelSyntaxNodes)
             {
-                try
+                switch (topLevelSyntaxNode)
                 {
-                    functions.Add(CheckFuncDefinition(funcSyntax));
+                    case EnumSyntax:
-                }
+                        break;
-                catch (TypeCheckerException e)
+                    case FuncSyntax funcSyntax:
-                {
+                        topLevelNodes.Add(CheckFuncDefinition(funcSyntax));
-                    Diagnostics.Add(e.Diagnostic);
+                        break;
+                    case StructSyntax structSyntax:
+                        topLevelNodes.Add(CheckStructDefinition(structSyntax));
+                        break;
+                    case ImportSyntax importSyntax:
+                        topLevelNodes.Add(new ImportNode(importSyntax.Tokens, importSyntax.NameToken));
+                        break;
+                    case ModuleSyntax moduleSyntax:
+                        topLevelNodes.Add(new ModuleNode(moduleSyntax.Tokens, moduleSyntax.NameToken));
+                        break;
+                    default:
+                        throw new ArgumentOutOfRangeException(nameof(topLevelSyntaxNode));
                 }
             }
         }
 
-        var importedStructTypes = new Dictionary<IdentifierToken, List<NubStructType>>();
+        return topLevelNodes;
-        var importedFunctions = new Dictionary<IdentifierToken, List<FuncPrototypeNode>>();
-
-        foreach (var (name, module) in GetImportedModules())
-        {
-            var moduleStructs = new List<NubStructType>();
-            var moduleFunctions = new List<FuncPrototypeNode>();
-
-            using (BeginRootScope(name))
-            {
-                foreach (var structSyntax in module.Structs(true))
-                {
-                    try
-                    {
-                        var fields = structSyntax.Fields
-                            .Select(f => new NubStructFieldType(f.NameToken.Value, ResolveType(f.Type), f.Value != null))
-                            .ToList();
-
-                        moduleStructs.Add(new NubStructType(name.Value, structSyntax.NameToken.Value, fields));
-                    }
-                    catch (TypeCheckerException e)
-                    {
-                        Diagnostics.Add(e.Diagnostic);
-                    }
     }
 
-                importedStructTypes[name] = moduleStructs;
+    private (IdentifierToken Name, Module Module) GetCurrentModule()
-
-                foreach (var funcSyntax in module.Functions(true))
     {
-                    try
+        var currentModule = _syntaxTree.TopLevelSyntaxNodes.OfType<ModuleSyntax>().First().NameToken;
-                    {
+        return (currentModule, _modules[currentModule.Value]);
-                        moduleFunctions.Add(CheckFuncPrototype(funcSyntax.Prototype));
-                    }
-                    catch (TypeCheckerException e)
-                    {
-                        Diagnostics.Add(e.Diagnostic);
-                    }
-                }
-
-                importedFunctions[name] = moduleFunctions;
-            }
-        }
-
-        return new CompilationUnit(moduleName, functions, importedStructTypes, importedFunctions);
     }
 
     private List<(IdentifierToken Name, Module Module)> GetImportedModules()
@@ -225,19 +197,48 @@ public sealed class TypeChecker
         }
     }
 
+    private StructNode CheckStructDefinition(StructSyntax structSyntax)
+    {
+        var fields = new List<StructFieldNode>();
+
+        foreach (var field in structSyntax.Fields)
+        {
+            var fieldType = _typeResolver.ResolveType(field.Type, Scope.Module.Value);
+            ExpressionNode? value = null;
+            if (field.Value != null)
+            {
+                value = CheckExpression(field.Value, fieldType);
+                if (value.Type != fieldType)
+                {
+                    throw new CompileException(Diagnostic
+                        .Error($"Type {value.Type} is not assignable to {field.Type} for field {field.NameToken.Value}")
+                        .At(field)
+                        .Build());
+                }
+            }
+
+            fields.Add(new StructFieldNode(field.Tokens, field.NameToken, fieldType, value));
+        }
+
+        var currentModule = GetCurrentModule();
+        var type = new NubStructType(currentModule.Name.Value, structSyntax.NameToken.Value, fields.Select(x => new NubStructFieldType(x.NameToken.Value, x.Type, x.Value != null)).ToList());
+
+        return new StructNode(structSyntax.Tokens, structSyntax.NameToken, type, fields);
+    }
+
     private AssignmentNode CheckAssignment(AssignmentSyntax statement)
     {
         var target = CheckExpression(statement.Target);
         if (target is not LValueExpressionNode lValue)
         {
-            throw new TypeCheckerException(Diagnostic.Error("Cannot assign to an rvalue").At(statement).Build());
+            throw new CompileException(Diagnostic.Error("Cannot assign to an rvalue").At(statement).Build());
         }
 
         var value = CheckExpression(statement.Value, lValue.Type);
 
         if (value.Type != lValue.Type)
         {
-            throw new TypeCheckerException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error($"Cannot assign {value.Type} to {lValue.Type}")
                 .At(statement.Value)
                 .Build());
@@ -279,7 +280,7 @@ public sealed class TypeChecker
         return expression switch
         {
             FuncCallNode funcCall => new StatementFuncCallNode(statement.Tokens, funcCall),
-            _ => throw new TypeCheckerException(Diagnostic.Error("Expressions statements can only be function calls").At(statement).Build())
+            _ => throw new CompileException(Diagnostic.Error("Expressions statements can only be function calls").At(statement).Build())
         };
     }
 
@@ -290,7 +291,7 @@ public sealed class TypeChecker
 
         if (statement.ExplicitType != null)
         {
-            type = ResolveType(statement.ExplicitType);
+            type = _typeResolver.ResolveType(statement.ExplicitType, Scope.Module.Value);
         }
 
         if (statement.Assignment != null)
@@ -303,7 +304,7 @@ public sealed class TypeChecker
             }
             else if (assignmentNode.Type != type)
             {
-                throw new TypeCheckerException(Diagnostic
+                throw new CompileException(Diagnostic
                     .Error($"Cannot assign {assignmentNode.Type} to variable of type {type}")
                     .At(statement.Assignment)
                     .Build());
@@ -312,7 +313,7 @@ public sealed class TypeChecker
 
         if (type == null)
         {
-            throw new TypeCheckerException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error($"Cannot infer type of variable {statement.NameToken.Value}")
                 .At(statement)
                 .Build());
@@ -367,7 +368,7 @@ public sealed class TypeChecker
             }
             default:
             {
-                throw new TypeCheckerException(Diagnostic
+                throw new CompileException(Diagnostic
                     .Error($"Cannot iterate over type {target.Type} which does not have size information")
                     .At(forSyntax.Target)
                     .Build());
@@ -380,10 +381,10 @@ public sealed class TypeChecker
         var parameters = new List<FuncParameterNode>();
         foreach (var parameter in statement.Parameters)
         {
-            parameters.Add(new FuncParameterNode(parameter.Tokens, parameter.NameToken, ResolveType(parameter.Type)));
+            parameters.Add(new FuncParameterNode(parameter.Tokens, parameter.NameToken, _typeResolver.ResolveType(parameter.Type, Scope.Module.Value)));
         }
 
-        return new FuncPrototypeNode(statement.Tokens, statement.NameToken, statement.ExternSymbolToken, parameters, ResolveType(statement.ReturnType));
+        return new FuncPrototypeNode(statement.Tokens, statement.NameToken, statement.ExternSymbolToken, parameters, _typeResolver.ResolveType(statement.ReturnType, Scope.Module.Value));
     }
 
     private ExpressionNode CheckExpression(ExpressionSyntax node, NubType? expectedType = null)
@@ -405,7 +406,7 @@ public sealed class TypeChecker
             FloatLiteralSyntax expression => CheckFloatLiteral(expression, expectedType),
             MemberAccessSyntax expression => CheckMemberAccess(expression, expectedType),
             StructInitializerSyntax expression => CheckStructInitializer(expression, expectedType),
-            SizeSyntax expression => new SizeNode(node.Tokens, ResolveType(expression.Type)),
+            SizeSyntax expression => new SizeNode(node.Tokens, _typeResolver.ResolveType(expression.Type, Scope.Module.Value)),
             CastSyntax expression => CheckCast(expression, expectedType),
             _ => throw new ArgumentOutOfRangeException(nameof(node))
         };
@@ -430,7 +431,7 @@ public sealed class TypeChecker
     {
         if (expectedType == null)
         {
-            throw new TypeCheckerException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error("Unable to infer target type of cast")
                 .At(expression)
                 .WithHelp("Specify target type where value is used")
@@ -451,7 +452,7 @@ public sealed class TypeChecker
 
         if (!IsCastAllowed(value.Type, expectedType, false))
         {
-            throw new TypeCheckerException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error($"Cannot cast from {value.Type} to {expectedType}")
                 .Build());
         }
@@ -500,7 +501,7 @@ public sealed class TypeChecker
         var target = CheckExpression(expression.Target, (expectedType as NubPointerType)?.BaseType);
         if (target is not LValueExpressionNode lvalue)
         {
-            throw new TypeCheckerException(Diagnostic.Error("Cannot take address of an rvalue").At(expression).Build());
+            throw new CompileException(Diagnostic.Error("Cannot take address of an rvalue").At(expression).Build());
         }
 
         var type = new NubPointerType(target.Type);
@@ -512,7 +513,7 @@ public sealed class TypeChecker
         var index = CheckExpression(expression.Index);
         if (index.Type is not NubIntType)
         {
-            throw new TypeCheckerException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error("Array indexer must be of type int")
                 .At(expression.Index)
                 .Build());
@@ -525,7 +526,7 @@ public sealed class TypeChecker
             NubArrayType arrayType => new ArrayIndexAccessNode(expression.Tokens, arrayType.ElementType, target, index),
             NubConstArrayType constArrayType => new ConstArrayIndexAccessNode(expression.Tokens, constArrayType.ElementType, target, index),
             NubSliceType sliceType => new SliceIndexAccessNode(expression.Tokens, sliceType.ElementType, target, index),
-            _ => throw new TypeCheckerException(Diagnostic.Error($"Cannot use array indexer on type {target.Type}").At(expression).Build())
+            _ => throw new CompileException(Diagnostic.Error($"Cannot use array indexer on type {target.Type}").At(expression).Build())
         };
     }
 
@@ -550,7 +551,7 @@ public sealed class TypeChecker
 
         if (elementType == null)
         {
-            throw new TypeCheckerException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error("Unable to infer type of array initializer")
                 .At(expression)
                 .WithHelp("Provide a type for a variable assignment")
@@ -563,7 +564,7 @@ public sealed class TypeChecker
             var value = CheckExpression(valueExpression, elementType);
             if (value.Type != elementType)
             {
-                throw new TypeCheckerException(Diagnostic
+                throw new CompileException(Diagnostic
                     .Error("Value in array initializer is not the same as the array type")
                     .At(valueExpression)
                     .Build());
@@ -613,7 +614,7 @@ public sealed class TypeChecker
                 var left = CheckExpression(expression.Left);
                 if (left.Type is not NubIntType and not NubFloatType and not NubBoolType)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("Equal and not equal operators must must be used with int, float or bool types")
                         .At(expression.Left)
                         .Build());
@@ -622,7 +623,7 @@ public sealed class TypeChecker
                 var right = CheckExpression(expression.Right, left.Type);
                 if (right.Type != left.Type)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error($"Expected type {left.Type} from left side of binary expression, but got {right.Type}")
                         .At(expression.Right)
                         .Build());
@@ -638,7 +639,7 @@ public sealed class TypeChecker
                 var left = CheckExpression(expression.Left);
                 if (left.Type is not NubIntType and not NubFloatType)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("Greater than and less than operators must must be used with int or float types")
                         .At(expression.Left)
                         .Build());
@@ -647,7 +648,7 @@ public sealed class TypeChecker
                 var right = CheckExpression(expression.Right, left.Type);
                 if (right.Type != left.Type)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error($"Expected type {left.Type} from left side of binary expression, but got {right.Type}")
                         .At(expression.Right)
                         .Build());
@@ -661,7 +662,7 @@ public sealed class TypeChecker
                 var left = CheckExpression(expression.Left);
                 if (left.Type is not NubBoolType)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("Logical and/or must must be used with bool types")
                         .At(expression.Left)
                         .Build());
@@ -670,7 +671,7 @@ public sealed class TypeChecker
                 var right = CheckExpression(expression.Right, left.Type);
                 if (right.Type != left.Type)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error($"Expected type {left.Type} from left side of binary expression, but got {right.Type}")
                         .At(expression.Right)
                         .Build());
@@ -683,7 +684,7 @@ public sealed class TypeChecker
                 var left = CheckExpression(expression.Left, expectedType);
                 if (left.Type is not NubIntType and not NubFloatType)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("The plus operator must only be used with int and float types")
                         .At(expression.Left)
                         .Build());
@@ -692,7 +693,7 @@ public sealed class TypeChecker
                 var right = CheckExpression(expression.Right, left.Type);
                 if (right.Type != left.Type)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error($"Expected type {left.Type} from left side of binary expression, but got {right.Type}")
                         .At(expression.Right)
                         .Build());
@@ -708,7 +709,7 @@ public sealed class TypeChecker
                 var left = CheckExpression(expression.Left, expectedType);
                 if (left.Type is not NubIntType and not NubFloatType)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("Math operators must be used with int or float types")
                         .At(expression.Left)
                         .Build());
@@ -717,7 +718,7 @@ public sealed class TypeChecker
                 var right = CheckExpression(expression.Right, left.Type);
                 if (right.Type != left.Type)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error($"Expected type {left.Type} from left side of binary expression, but got {right.Type}")
                         .At(expression.Right)
                         .Build());
@@ -734,7 +735,7 @@ public sealed class TypeChecker
                 var left = CheckExpression(expression.Left, expectedType);
                 if (left.Type is not NubIntType)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("Bitwise operators must be used with int types")
                         .At(expression.Left)
                         .Build());
@@ -743,7 +744,7 @@ public sealed class TypeChecker
                 var right = CheckExpression(expression.Right, left.Type);
                 if (right.Type != left.Type)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error($"Expected type {left.Type} from left side of binary expression, but got {right.Type}")
                         .At(expression.Right)
                         .Build());
@@ -767,7 +768,7 @@ public sealed class TypeChecker
                 var operand = CheckExpression(expression.Operand, expectedType);
                 if (operand.Type is not NubIntType { Signed: true } and not NubFloatType)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("Negation operator must be used with signed integer or float types")
                         .At(expression)
                         .Build());
@@ -780,7 +781,7 @@ public sealed class TypeChecker
                 var operand = CheckExpression(expression.Operand, expectedType);
                 if (operand.Type is not NubBoolType)
                 {
-                    throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("Invert operator must be used with booleans")
                         .At(expression)
                         .Build());
@@ -795,15 +796,16 @@ public sealed class TypeChecker
         }
     }
 
-    private DereferenceNode CheckDereference(DereferenceSyntax expression, NubType? _)
+    private ExpressionNode CheckDereference(DereferenceSyntax expression, NubType? _)
     {
         var target = CheckExpression(expression.Target);
-        if (target.Type is not NubPointerType pointerType)
-        {
-            throw new TypeCheckerException(Diagnostic.Error($"Cannot dereference non-pointer type {target.Type}").At(expression).Build());
-        }
 
-        return new DereferenceNode(expression.Tokens, pointerType.BaseType, target);
+        return target.Type switch
+        {
+            NubPointerType pointerType => new DereferenceNode(expression.Tokens, pointerType.BaseType, target),
+            NubRefType refType => new RefDereferenceNode(expression.Tokens, refType.BaseType, target),
+            _ => throw new CompileException(Diagnostic.Error($"Cannot dereference non-pointer type {target.Type}").At(expression).Build())
+        };
     }
 
     private FuncCallNode CheckFuncCall(FuncCallSyntax expression, NubType? _)
@@ -811,12 +813,12 @@ public sealed class TypeChecker
         var accessor = CheckExpression(expression.Expression);
         if (accessor.Type is not NubFuncType funcType)
         {
-            throw new TypeCheckerException(Diagnostic.Error($"Cannot call non-function type {accessor.Type}").At(expression.Expression).Build());
+            throw new CompileException(Diagnostic.Error($"Cannot call non-function type {accessor.Type}").At(expression.Expression).Build());
         }
 
         if (expression.Parameters.Count != funcType.Parameters.Count)
         {
-            throw new TypeCheckerException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error($"Function {funcType} expects {funcType.Parameters.Count} parameters but got {expression.Parameters.Count}")
                 .At(expression.Parameters.LastOrDefault(expression))
                 .Build());
@@ -831,7 +833,7 @@ public sealed class TypeChecker
             var parameterExpression = CheckExpression(parameter, expectedParameterType);
             if (parameterExpression.Type != expectedParameterType)
             {
-                throw new TypeCheckerException(Diagnostic
+                throw new CompileException(Diagnostic
                     .Error($"Parameter {i + 1} does not match the type {expectedParameterType} for function {funcType}")
                     .At(parameter)
                     .Build());
@@ -857,8 +859,8 @@ public sealed class TypeChecker
         var function = module.Functions(true).FirstOrDefault(x => x.NameToken.Value == expression.NameToken.Value);
         if (function != null)
         {
-            var parameters = function.Prototype.Parameters.Select(x => ResolveType(x.Type)).ToList();
+            var parameters = function.Prototype.Parameters.Select(x => _typeResolver.ResolveType(x.Type, Scope.Module.Value)).ToList();
-            var type = new NubFuncType(parameters, ResolveType(function.Prototype.ReturnType));
+            var type = new NubFuncType(parameters, _typeResolver.ResolveType(function.Prototype.ReturnType, Scope.Module.Value));
             return new FuncIdentifierNode(expression.Tokens, type, Scope.Module, expression.NameToken, function.Prototype.ExternSymbolToken);
         }
 
@@ -868,7 +870,7 @@ public sealed class TypeChecker
             return new EnumReferenceIntermediateNode(expression.Tokens, Scope.Module, expression.NameToken);
         }
 
-        throw new TypeCheckerException(Diagnostic
+        throw new CompileException(Diagnostic
             .Error($"There is no identifier named {expression.NameToken.Value}")
             .At(expression)
             .Build());
@@ -879,7 +881,7 @@ public sealed class TypeChecker
         var module = GetImportedModule(expression.ModuleToken.Value);
         if (module == null)
         {
-            throw new TypeCheckerException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error($"Module {expression.ModuleToken.Value} not found")
                 .WithHelp($"import \"{expression.ModuleToken.Value}\"")
                 .At(expression.ModuleToken)
@@ -891,8 +893,8 @@ public sealed class TypeChecker
         {
             using (BeginRootScope(expression.ModuleToken))
             {
-                var parameters = function.Prototype.Parameters.Select(x => ResolveType(x.Type)).ToList();
+                var parameters = function.Prototype.Parameters.Select(x => _typeResolver.ResolveType(x.Type, Scope.Module.Value)).ToList();
-                var type = new NubFuncType(parameters, ResolveType(function.Prototype.ReturnType));
+                var type = new NubFuncType(parameters, _typeResolver.ResolveType(function.Prototype.ReturnType, Scope.Module.Value));
                 return new FuncIdentifierNode(expression.Tokens, type, expression.ModuleToken, expression.NameToken, function.Prototype.ExternSymbolToken);
             }
         }
@@ -903,7 +905,7 @@ public sealed class TypeChecker
             return new EnumReferenceIntermediateNode(expression.Tokens, expression.ModuleToken, expression.NameToken);
         }
 
-        throw new TypeCheckerException(Diagnostic
+        throw new CompileException(Diagnostic
             .Error($"Module {expression.ModuleToken.Value} does not export a member named {expression.NameToken.Value}")
             .At(expression)
             .Build());
@@ -981,16 +983,16 @@ public sealed class TypeChecker
             var field = enumDef.Fields.FirstOrDefault(x => x.NameToken.Value == expression.MemberToken.Value);
             if (field == null)
             {
-                throw new TypeCheckerException(Diagnostic
+                throw new CompileException(Diagnostic
                     .Error($"Enum {Scope.Module.Value}::{enumReferenceIntermediate.NameToken.Value} does not have a field named {expression.MemberToken.Value}")
                     .At(enumDef)
                     .Build());
             }
 
-            var enumType = enumDef.Type != null ? ResolveType(enumDef.Type) : new NubIntType(false, 64);
+            var enumType = enumDef.Type != null ? _typeResolver.ResolveType(enumDef.Type, Scope.Module.Value) : new NubIntType(false, 64);
             if (enumType is not NubIntType enumIntType)
             {
-                throw new TypeCheckerException(Diagnostic.Error("Enum type must be an int type").At(enumDef.Type).Build());
+                throw new CompileException(Diagnostic.Error("Enum type must be an int type").At(enumDef.Type).Build());
             }
 
             if (enumIntType.Signed)
@@ -1019,12 +1021,14 @@ public sealed class TypeChecker
             }
         }
 
-        if (target.Type is NubStructType structType)
+        switch (target.Type)
+        {
+            case NubStructType structType:
             {
                 var field = structType.Fields.FirstOrDefault(x => x.Name == expression.MemberToken.Value);
                 if (field == null)
                 {
-                throw new TypeCheckerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error($"Struct {target.Type} does not have a field with the name {expression.MemberToken.Value}")
                         .At(expression)
                         .Build());
@@ -1032,12 +1036,15 @@ public sealed class TypeChecker
 
                 return new StructFieldAccessNode(expression.Tokens, field.Type, target, expression.MemberToken);
             }
-
+            default:
-        throw new TypeCheckerException(Diagnostic
+            {
+                throw new CompileException(Diagnostic
                     .Error($"Cannot access struct member {expression.MemberToken.Value} on type {target.Type}")
                     .At(expression)
                     .Build());
             }
+        }
+    }
 
     private static long CalculateSignedEnumFieldValue(EnumSyntax enumDef, EnumFieldSyntax field)
     {
@@ -1083,13 +1090,13 @@ public sealed class TypeChecker
         throw new UnreachableException();
     }
 
-    private StructInitializerNode CheckStructInitializer(StructInitializerSyntax expression, NubType? expectedType)
+    private ExpressionNode CheckStructInitializer(StructInitializerSyntax expression, NubType? expectedType)
     {
         NubStructType? structType = null;
 
         if (expression.StructType != null)
         {
-            var checkedType = ResolveType(expression.StructType);
+            var checkedType = _typeResolver.ResolveType(expression.StructType, Scope.Module.Value);
             if (checkedType is not NubStructType checkedStructType)
             {
                 throw new UnreachableException("Parser fucked up");
@@ -1097,14 +1104,19 @@ public sealed class TypeChecker
 
             structType = checkedStructType;
         }
-        else if (expectedType is NubStructType expectedStructType)
+        else
         {
-            structType = expectedStructType;
+            structType = expectedType switch
+            {
+                NubStructType expectedStructType => expectedStructType,
+                NubRefType { BaseType: NubStructType expectedStructType } => expectedStructType,
+                _ => structType
+            };
         }
 
         if (structType == null)
         {
-            throw new TypeCheckerException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error("Cannot get implicit type of struct")
                 .WithHelp("Specify struct type with struct {type_name} syntax")
                 .At(expression)
@@ -1142,8 +1154,15 @@ public sealed class TypeChecker
                 .Build());
         }
 
+        if (expectedType is NubRefType refType && refType.BaseType == structType)
+        {
+            return new RefStructInitializerNode(expression.Tokens, refType, initializers);
+        }
+        else
+        {
             return new StructInitializerNode(expression.Tokens, structType, initializers);
         }
+    }
 
     private BlockNode CheckBlock(BlockSyntax node)
     {
@@ -1156,7 +1175,7 @@ public sealed class TypeChecker
                 {
                     statements.Add(CheckStatement(statement));
                 }
-                catch (TypeCheckerException e)
+                catch (CompileException e)
                 {
                     Diagnostics.Add(e.Diagnostic);
                 }
@@ -1184,84 +1203,6 @@ public sealed class TypeChecker
             _ => throw new ArgumentOutOfRangeException(nameof(statement))
         };
     }
-
-    private NubType ResolveType(TypeSyntax type)
-    {
-        return type switch
-        {
-            ArrayTypeSyntax arr => new NubArrayType(ResolveType(arr.BaseType)),
-            BoolTypeSyntax => new NubBoolType(),
-            IntTypeSyntax i => new NubIntType(i.Signed, i.Width),
-            FloatTypeSyntax f => new NubFloatType(f.Width),
-            FuncTypeSyntax func => new NubFuncType(func.Parameters.Select(ResolveType).ToList(), ResolveType(func.ReturnType)),
-            SliceTypeSyntax slice => new NubSliceType(ResolveType(slice.BaseType)),
-            ConstArrayTypeSyntax arr => new NubConstArrayType(ResolveType(arr.BaseType), arr.Size),
-            PointerTypeSyntax ptr => new NubPointerType(ResolveType(ptr.BaseType)),
-            StringTypeSyntax => new NubStringType(),
-            CustomTypeSyntax c => ResolveCustomType(c),
-            VoidTypeSyntax => new NubVoidType(),
-            _ => throw new NotSupportedException($"Unknown type syntax: {type}")
-        };
-    }
-
-    private NubType ResolveCustomType(CustomTypeSyntax customType)
-    {
-        var module = GetImportedModule(customType.ModuleToken?.Value ?? Scope.Module.Value);
-        if (module == null)
-        {
-            throw new TypeCheckerException(Diagnostic
-                .Error($"Module {customType.ModuleToken?.Value ?? Scope.Module.Value} not found")
-                .WithHelp($"import \"{customType.ModuleToken?.Value ?? Scope.Module.Value}\"")
-                .At(customType)
-                .Build());
-        }
-
-        var enumDef = module.Enums(IsCurrentModule(customType.ModuleToken)).FirstOrDefault(x => x.NameToken.Value == customType.NameToken.Value);
-        if (enumDef != null)
-        {
-            return enumDef.Type != null ? ResolveType(enumDef.Type) : new NubIntType(false, 64);
-        }
-
-        var structDef = module.Structs(IsCurrentModule(customType.ModuleToken)).FirstOrDefault(x => x.NameToken.Value == customType.NameToken.Value);
-        if (structDef != null)
-        {
-            var key = (customType.ModuleToken?.Value ?? Scope.Module.Value, customType.NameToken.Value);
-
-            if (_typeCache.TryGetValue(key, out var cachedType))
-            {
-                return cachedType;
-            }
-
-            if (!_resolvingTypes.Add(key))
-            {
-                var placeholder = new NubStructType(customType.ModuleToken?.Value ?? Scope.Module.Value, customType.NameToken.Value, []);
-                _typeCache[key] = placeholder;
-                return placeholder;
-            }
-
-            try
-            {
-                var result = new NubStructType(customType.ModuleToken?.Value ?? Scope.Module.Value, structDef.NameToken.Value, []);
-                _typeCache[key] = result;
-
-                var fields = structDef.Fields
-                    .Select(x => new NubStructFieldType(x.NameToken.Value, ResolveType(x.Type), x.Value != null))
-                    .ToList();
-
-                result.Fields.AddRange(fields);
-                return result;
-            }
-            finally
-            {
-                _resolvingTypes.Remove(key);
-            }
-        }
-
-        throw new TypeCheckerException(Diagnostic
-            .Error($"Type {customType.NameToken.Value} not found in module {customType.ModuleToken?.Value ?? Scope.Module.Value}")
-            .At(customType)
-            .Build());
-    }
 }
 
 public record Variable(IdentifierToken Name, NubType Type);
@@ -1303,13 +1244,3 @@ public class Scope(IdentifierToken module, Scope? parent = null)
         return new Scope(Module, this);
     }
 }
-
-public class TypeCheckerException : Exception
-{
-    public Diagnostic Diagnostic { get; }
-
-    public TypeCheckerException(Diagnostic diagnostic) : base(diagnostic.Message)
-    {
-        Diagnostic = diagnostic;
-    }
-}

compiler/NubLang/Ast/TypeResolver.cs

@@ -0,0 +1,97 @@
+using NubLang.Diagnostics;
+using NubLang.Syntax;
+
+namespace NubLang.Ast;
+
+public class TypeResolver
+{
+    private readonly Dictionary<string, Module> _modules;
+    private readonly Dictionary<(string Module, string Name), NubType> _typeCache = new();
+    private readonly HashSet<(string Module, string Name)> _resolvingTypes = [];
+
+    public TypeResolver(Dictionary<string, Module> modules)
+    {
+        _modules = modules;
+    }
+
+    public NubType ResolveType(TypeSyntax type, string currentModule)
+    {
+        return type switch
+        {
+            ArrayTypeSyntax arr => new NubArrayType(ResolveType(arr.BaseType, currentModule)),
+            BoolTypeSyntax => new NubBoolType(),
+            IntTypeSyntax i => new NubIntType(i.Signed, i.Width),
+            FloatTypeSyntax f => new NubFloatType(f.Width),
+            FuncTypeSyntax func => new NubFuncType(func.Parameters.Select(x => ResolveType(x, currentModule)).ToList(), ResolveType(func.ReturnType, currentModule)),
+            SliceTypeSyntax slice => new NubSliceType(ResolveType(slice.BaseType, currentModule)),
+            ConstArrayTypeSyntax arr => new NubConstArrayType(ResolveType(arr.BaseType, currentModule), arr.Size),
+            PointerTypeSyntax ptr => new NubPointerType(ResolveType(ptr.BaseType, currentModule)),
+            RefTypeSyntax r => new NubRefType(ResolveType(r.BaseType, currentModule)),
+            StringTypeSyntax => new NubStringType(),
+            CustomTypeSyntax c => ResolveCustomType(c, currentModule),
+            VoidTypeSyntax => new NubVoidType(),
+            _ => throw new NotSupportedException($"Unknown type syntax: {type}")
+        };
+    }
+
+    private NubType ResolveCustomType(CustomTypeSyntax customType, string currentModule)
+    {
+        var module = _modules[customType.ModuleToken?.Value ?? currentModule];
+
+        var enumDef = module.Enums(true).FirstOrDefault(x => x.NameToken.Value == customType.NameToken.Value);
+        if (enumDef != null)
+        {
+            return enumDef.Type != null ? ResolveType(enumDef.Type, currentModule) : new NubIntType(false, 64);
+        }
+
+        var structDef = module.Structs(true).FirstOrDefault(x => x.NameToken.Value == customType.NameToken.Value);
+        if (structDef != null)
+        {
+            var key = (customType.ModuleToken?.Value ?? currentModule, customType.NameToken.Value);
+
+            if (_typeCache.TryGetValue(key, out var cachedType))
+            {
+                return cachedType;
+            }
+
+            if (!_resolvingTypes.Add(key))
+            {
+                var placeholder = new NubStructType(customType.ModuleToken?.Value ?? currentModule, customType.NameToken.Value, []);
+                _typeCache[key] = placeholder;
+                return placeholder;
+            }
+
+            try
+            {
+                var result = new NubStructType(customType.ModuleToken?.Value ?? currentModule, structDef.NameToken.Value, []);
+                _typeCache[key] = result;
+
+                var fields = structDef.Fields
+                    .Select(x => new NubStructFieldType(x.NameToken.Value, ResolveType(x.Type, currentModule), x.Value != null))
+                    .ToList();
+
+                result.Fields.AddRange(fields);
+                return result;
+            }
+            finally
+            {
+                _resolvingTypes.Remove(key);
+            }
+        }
+
+        throw new TypeResolverException(Diagnostic
+            .Error($"Type {customType.NameToken.Value} not found in module {customType.ModuleToken?.Value ?? currentModule}")
+            .At(customType)
+            .Build());
+    }
+}
+
+public class TypeResolverException : Exception
+{
+    public Diagnostic Diagnostic { get; }
+
+    public TypeResolverException(Diagnostic diagnostic) : base(diagnostic.Message)
+    {
+        Diagnostic = diagnostic;
+    }
+}

compiler/NubLang/Diagnostics/CompileException.cs

@@ -0,0 +1,11 @@
+namespace NubLang.Diagnostics;
+
+public class CompileException : Exception
+{
+    public Diagnostic Diagnostic { get; }
+
+    public CompileException(Diagnostic diagnostic) : base(diagnostic.Message)
+    {
+        Diagnostic = diagnostic;
+    }
+}

compiler/NubLang/Generation/CType.cs

@@ -10,15 +10,16 @@ public static class CType
         {
             NubVoidType => "void" + (variableName != null ? $" {variableName}" : ""),
             NubBoolType => "bool" + (variableName != null ? $" {variableName}" : ""),
-            NubIntType intType => CreateIntType(intType, variableName),
+            NubIntType i => CreateIntType(i, variableName),
-            NubFloatType floatType => CreateFloatType(floatType, variableName),
+            NubFloatType f => CreateFloatType(f, variableName),
-            NubPointerType ptr => CreatePointerType(ptr, variableName),
+            NubPointerType p => CreatePointerType(p, variableName),
-            NubSliceType => "struct nub_slice" + (variableName != null ? $" {variableName}" : ""),
+            NubRefType r => CreateRefType(r, variableName),
-            NubStringType => "struct nub_string" + (variableName != null ? $" {variableName}" : ""),
+            NubSliceType => "nub_slice" + (variableName != null ? $" {variableName}" : ""),
-            NubConstArrayType arr => CreateConstArrayType(arr, variableName, constArraysAsPointers),
+            NubStringType => "nub_string" + (variableName != null ? $" {variableName}" : ""),
-            NubArrayType arr => CreateArrayType(arr, variableName),
+            NubConstArrayType a => CreateConstArrayType(a, variableName, constArraysAsPointers),
-            NubFuncType fn => CreateFuncType(fn, variableName),
+            NubArrayType a => CreateArrayType(a, variableName),
-            NubStructType st => $"struct {st.Module}_{st.Name}_{NameMangler.Mangle(st)}" + (variableName != null ? $" {variableName}" : ""),
+            NubFuncType f => CreateFuncType(f, variableName),
+            NubStructType s => $"{s.Module}_{s.Name}_{NameMangler.Mangle(s)}" + (variableName != null ? $" {variableName}" : ""),
             _ => throw new NotSupportedException($"C type generation not supported for: {type}")
         };
     }
@@ -47,6 +48,12 @@ public static class CType
         return cType + (varName != null ? $" {varName}" : "");
     }
 
+    private static string CreateRefType(NubRefType ptr, string? varName)
+    {
+        var baseType = Create(ptr.BaseType);
+        return baseType + "*" + (varName != null ? $" {varName}" : "");
+    }
+
     private static string CreatePointerType(NubPointerType ptr, string? varName)
     {
         var baseType = Create(ptr.BaseType);

compiler/NubLang/Generation/Generator.cs

@@ -7,12 +7,14 @@ namespace NubLang.Generation;
 
 public class Generator
 {
-    private readonly CompilationUnit _compilationUnit;
+    private readonly List<TopLevelNode> _compilationUnit;
     private readonly IndentedTextWriter _writer;
-    private readonly Stack<List<DeferNode>> _deferStack = [];
+    private readonly Stack<Scope> _scopes = [];
     private int _tmpIndex;
 
-    public Generator(CompilationUnit compilationUnit)
+    private Scope Scope => _scopes.Peek();
+
+    public Generator(List<TopLevelNode> compilationUnit)
     {
         _compilationUnit = compilationUnit;
         _writer = new IndentedTextWriter();
@@ -29,60 +31,51 @@ public class Generator
         return externSymbol ?? $"{module}_{name}";
     }
 
+    private string GetModuleName()
+    {
+        return _compilationUnit.OfType<ModuleNode>().First().NameToken.Value;
+    }
+
     public string Emit()
     {
-        _writer.WriteLine("""
+        foreach (var structType in _compilationUnit.OfType<StructNode>())
-                          struct nub_string
         {
-                              unsigned long long length;
+            _writer.WriteLine($"void {CType.Create(structType.StructType)}_create({CType.Create(structType.StructType)} *self)");
-                              char *data;
-                          };
-
-                          struct nub_slice
-                          {
-                              unsigned long long length;
-                              void *data;
-                          };
-
-                          """);
-
-        foreach (var (_, structTypes) in _compilationUnit.ImportedStructTypes)
-        {
-            foreach (var structType in structTypes)
-            {
-                _writer.WriteLine(CType.Create(structType));
             _writer.WriteLine("{");
             using (_writer.Indent())
             {
                 foreach (var field in structType.Fields)
                 {
-                        _writer.WriteLine($"{CType.Create(field.Type, field.Name, constArraysAsPointers: false)};");
+                    if (field.Value != null)
-                    }
-                }
-
-                _writer.WriteLine("};");
-                _writer.WriteLine();
-            }
-        }
-
-        // note(nub31): Forward declarations
-        foreach (var (module, prototypes) in _compilationUnit.ImportedFunctions)
                     {
-            foreach (var prototype in prototypes)
+                        var value = EmitExpression(field.Value);
-            {
+                        _writer.WriteLine($"self->{field.NameToken.Value} = {value}");
-                EmitLine(prototype.Tokens.FirstOrDefault());
-                var parameters = prototype.Parameters.Count != 0
-                    ? string.Join(", ", prototype.Parameters.Select(x => CType.Create(x.Type, x.NameToken.Value)))
-                    : "void";
-
-                var name = FuncName(module.Value, prototype.NameToken.Value, prototype.ExternSymbolToken?.Value);
-                _writer.WriteLine($"{CType.Create(prototype.ReturnType, name)}({parameters});");
-                _writer.WriteLine();
                     }
                 }
+            }
+
+            _writer.WriteLine("}");
+            _writer.WriteLine();
+
+            _writer.WriteLine($"void {CType.Create(structType.StructType)}_destroy({CType.Create(structType.StructType)} *self)");
+            _writer.WriteLine("{");
+            using (_writer.Indent())
+            {
+                foreach (var field in structType.Fields)
+                {
+                    if (field.Type is NubRefType)
+                    {
+                        _writer.WriteLine($"rc_release(self->{field.NameToken.Value});");
+                    }
+                }
+            }
+
+            _writer.WriteLine("}");
+            _writer.WriteLine();
+        }
 
         // note(nub31): Normal functions
-        foreach (var funcNode in _compilationUnit.Functions)
+        foreach (var funcNode in _compilationUnit.OfType<FuncNode>())
         {
             if (funcNode.Body == null) continue;
 
@@ -91,13 +84,24 @@ public class Generator
                 ? string.Join(", ", funcNode.Prototype.Parameters.Select(x => CType.Create(x.Type, x.NameToken.Value)))
                 : "void";
 
-            var name = FuncName(_compilationUnit.Module.Value, funcNode.NameToken.Value, funcNode.Prototype.ExternSymbolToken?.Value);
+            var name = FuncName(GetModuleName(), funcNode.NameToken.Value, funcNode.Prototype.ExternSymbolToken?.Value);
             _writer.WriteLine($"{CType.Create(funcNode.Prototype.ReturnType, name)}({parameters})");
             _writer.WriteLine("{");
             using (_writer.Indent())
             {
+                using (BeginScope())
+                {
+                    foreach (var parameter in funcNode.Prototype.Parameters)
+                    {
+                        if (parameter.Type is NubRefType)
+                        {
+                            Scope.Defer(() => _writer.WriteLine($"rc_release({parameter.NameToken.Value});"));
+                        }
+                    }
+
                     EmitBlock(funcNode.Body);
                 }
+            }
 
             _writer.WriteLine("}");
             _writer.WriteLine();
@@ -117,9 +121,12 @@ public class Generator
             case BlockNode blockNode:
                 _writer.WriteLine("{");
                 using (_writer.Indent())
+                {
+                    using (BeginScope())
                     {
                         EmitBlock(blockNode);
                     }
+                }
 
                 _writer.WriteLine("}");
                 break;
@@ -130,7 +137,7 @@ public class Generator
                 EmitContinue(continueNode);
                 break;
             case DeferNode deferNode:
-                EmitDefer(deferNode);
+                Scope.Defer(() => EmitStatement(deferNode.Statement));
                 break;
             case ForConstArrayNode forConstArrayNode:
                 EmitForConstArray(forConstArrayNode);
@@ -170,6 +177,14 @@ public class Generator
     {
         var target = EmitExpression(assignmentNode.Target);
         var value = EmitExpression(assignmentNode.Value);
+
+        if (assignmentNode.Target.Type is NubRefType)
+        {
+            _writer.WriteLine($"rc_retain({value});");
+            Scope.Defer(() => _writer.WriteLine($"rc_release({value});"));
+            _writer.WriteLine($"rc_release({target});");
+        }
+
         _writer.WriteLine($"{target} = {value};");
     }
 
@@ -185,11 +200,6 @@ public class Generator
         _writer.WriteLine("continue;");
     }
 
-    private void EmitDefer(DeferNode deferNode)
-    {
-        _deferStack.Peek().Add(deferNode);
-    }
-
     private void EmitForSlice(ForSliceNode forSliceNode)
     {
         var targetType = (NubSliceType)forSliceNode.Target.Type;
@@ -199,10 +209,13 @@ public class Generator
         _writer.WriteLine($"for (unsigned long long {indexName} = 0; {indexName} < {target}.length; ++{indexName})");
         _writer.WriteLine("{");
         using (_writer.Indent())
+        {
+            using (BeginScope())
             {
                 _writer.WriteLine($"{CType.Create(targetType.ElementType, forSliceNode.ElementNameToken.Value)} = (({CType.Create(targetType.ElementType)}*){target}.data)[{indexName}];");
                 EmitBlock(forSliceNode.Body);
             }
+        }
 
         _writer.WriteLine("}");
     }
@@ -216,10 +229,13 @@ public class Generator
         _writer.WriteLine($"for (unsigned long long {indexName} = 0; {indexName} < {targetType.Size}; ++{indexName})");
         _writer.WriteLine("{");
         using (_writer.Indent())
+        {
+            using (BeginScope())
             {
                 _writer.WriteLine($"{CType.Create(targetType.ElementType, forConstArrayNode.ElementNameToken.Value)} = {target}[{indexName}];");
                 EmitBlock(forConstArrayNode.Body);
             }
+        }
 
         _writer.WriteLine("}");
     }
@@ -230,9 +246,12 @@ public class Generator
         _writer.WriteLine($"{(elseIf ? "else " : "")}if ({condition})");
         _writer.WriteLine("{");
         using (_writer.Indent())
+        {
+            using (BeginScope())
             {
                 EmitBlock(ifNode.Body);
             }
+        }
 
         _writer.WriteLine("}");
         ifNode.Else?.Match
@@ -243,9 +262,12 @@ public class Generator
                 _writer.WriteLine("else");
                 _writer.WriteLine("{");
                 using (_writer.Indent())
+                {
+                    using (BeginScope())
                     {
                         EmitBlock(elseNode);
                     }
+                }
 
                 _writer.WriteLine("}");
             }
@@ -256,44 +278,28 @@ public class Generator
     {
         if (returnNode.Value == null)
         {
-            var blockDefers = _deferStack.Peek();
+            EmitScopeCleanup();
-            for (var i = blockDefers.Count - 1; i >= 0; i--)
-            {
-                EmitStatement(blockDefers[i].Statement);
-            }
-
             _writer.WriteLine("return;");
         }
         else
         {
             var returnValue = EmitExpression(returnNode.Value);
-
-            if (_deferStack.Peek().Count != 0)
-            {
             var tmp = NewTmp();
             _writer.WriteLine($"{CType.Create(returnNode.Value.Type, tmp)} = {returnValue};");
-
+            if (returnNode.Value.Type is NubRefType)
-                var blockDefers = _deferStack.Peek();
-                for (var i = blockDefers.Count - 1; i >= 0; i--)
             {
-                    EmitStatement(blockDefers[i].Statement);
+                _writer.WriteLine($"rc_retain({tmp});");
             }
 
+            EmitScopeCleanup();
             EmitLine(returnNode.Tokens.FirstOrDefault());
             _writer.WriteLine($"return {tmp};");
         }
-            else
-            {
-                EmitLine(returnNode.Tokens.FirstOrDefault());
-                _writer.WriteLine($"return {returnValue};");
-            }
-        }
     }
 
     private void EmitStatementFuncCall(StatementFuncCallNode statementFuncCallNode)
     {
-        var funcCall = EmitFuncCall(statementFuncCallNode.FuncCall);
+        EmitFuncCall(statementFuncCallNode.FuncCall);
-        _writer.WriteLine($"{funcCall};");
     }
 
     private void EmitVariableDeclaration(VariableDeclarationNode variableDeclarationNode)
@@ -301,6 +307,13 @@ public class Generator
         if (variableDeclarationNode.Assignment != null)
         {
             var value = EmitExpression(variableDeclarationNode.Assignment);
+
+            if (variableDeclarationNode.Type is NubRefType)
+            {
+                _writer.WriteLine($"rc_retain({value});");
+                Scope.Defer(() => _writer.WriteLine($"rc_release({value});"));
+            }
+
             _writer.WriteLine($"{CType.Create(variableDeclarationNode.Type, variableDeclarationNode.NameToken.Value)} = {value};");
         }
         else
@@ -315,9 +328,12 @@ public class Generator
         _writer.WriteLine($"while ({condition})");
         _writer.WriteLine("{");
         using (_writer.Indent())
+        {
+            using (BeginScope())
             {
                 EmitBlock(whileNode.Body);
             }
+        }
 
         _writer.WriteLine("}");
     }
@@ -345,6 +361,8 @@ public class Generator
             FuncCallNode funcCallNode => EmitFuncCall(funcCallNode),
             FuncIdentifierNode funcIdentifierNode => FuncName(funcIdentifierNode.ModuleToken.Value, funcIdentifierNode.NameToken.Value, funcIdentifierNode.ExternSymbolToken?.Value),
             AddressOfNode addressOfNode => EmitAddressOf(addressOfNode),
+            RefDereferenceNode refDereferenceNode => EmitRefDereference(refDereferenceNode),
+            RefStructInitializerNode refStructInitializerNode => EmitRefStructInitializer(refStructInitializerNode),
             SizeNode sizeBuiltinNode => $"sizeof({CType.Create(sizeBuiltinNode.TargetType)})",
             SliceIndexAccessNode sliceIndexAccessNode => EmitSliceArrayIndexAccess(sliceIndexAccessNode),
             StringLiteralNode stringLiteralNode => EmitStringLiteral(stringLiteralNode),
@@ -479,8 +497,29 @@ public class Generator
     private string EmitFuncCall(FuncCallNode funcCallNode)
     {
         var name = EmitExpression(funcCallNode.Expression);
-        var parameterNames = funcCallNode.Parameters.Select(EmitExpression).ToList();
+
-        return $"{name}({string.Join(", ", parameterNames)})";
+        var parameterNames = new List<string>();
+        foreach (var parameter in funcCallNode.Parameters)
+        {
+            var result = EmitExpression(parameter);
+            if (parameter.Type is NubRefType)
+            {
+                _writer.WriteLine($"rc_retain({result});");
+            }
+
+            parameterNames.Add(result);
+        }
+
+        var tmp = NewTmp();
+
+        _writer.WriteLine($"{CType.Create(funcCallNode.Type)} {tmp} = {name}({string.Join(", ", parameterNames)});");
+
+        if (funcCallNode.Type is NubRefType)
+        {
+            Scope.Defer(() => _writer.WriteLine($"rc_release({tmp});"));
+        }
+
+        return tmp;
     }
 
     private string EmitAddressOf(AddressOfNode addressOfNode)
@@ -489,6 +528,33 @@ public class Generator
         return $"&{value}";
     }
 
+    private string EmitRefDereference(RefDereferenceNode refDereferenceNode)
+    {
+        var pointer = EmitExpression(refDereferenceNode.Target);
+        return $"*{pointer}";
+    }
+
+    private string EmitRefStructInitializer(RefStructInitializerNode refStructInitializerNode)
+    {
+        var type = (NubRefType)refStructInitializerNode.Type;
+        var structType = (NubStructType)type.BaseType;
+
+        var tmp = NewTmp();
+        _writer.WriteLine($"{CType.Create(type)} {tmp} = ({CType.Create(type)})rc_alloc(sizeof({CType.Create(structType)}), (void (*)(void *)){CType.Create(structType)}_destroy);");
+        Scope.Defer(() => _writer.WriteLine($"rc_release({tmp});"));
+
+        _writer.WriteLine($"*{tmp} = ({CType.Create(structType)}){{{0}}};");
+        _writer.WriteLine($"{CType.Create(structType)}_create({tmp});");
+
+        foreach (var initializer in refStructInitializerNode.Initializers)
+        {
+            var value = EmitExpression(initializer.Value);
+            _writer.WriteLine($"{tmp}->{initializer.Key} = {value};");
+        }
+
+        return tmp;
+    }
+
     private string EmitSliceArrayIndexAccess(SliceIndexAccessNode sliceIndexAccessNode)
     {
         var targetType = (NubSliceType)sliceIndexAccessNode.Target.Type;
@@ -501,7 +567,7 @@ public class Generator
     private string EmitStringLiteral(StringLiteralNode stringLiteralNode)
     {
         var length = Encoding.UTF8.GetByteCount(stringLiteralNode.Value);
-        return $"(nub_string){{.length = {length}, .data = \"{stringLiteralNode.Value}\"}}";
+        return $"({CType.Create(stringLiteralNode.Type)}){{.length = {length}, .data = \"{stringLiteralNode.Value}\"}}";
     }
 
     private string EmitStructFieldAccess(StructFieldAccessNode structFieldAccessNode)
@@ -512,18 +578,19 @@ public class Generator
 
     private string EmitStructInitializer(StructInitializerNode structInitializerNode)
     {
-        var initValues = new List<string>();
+        var structType = (NubStructType)structInitializerNode.Type;
+
+        var tmp = NewTmp();
+        _writer.WriteLine($"{CType.Create(structType)} {tmp} = ({CType.Create(structType)}){{0}};");
+        _writer.WriteLine($"{CType.Create(structType)}_create(&{tmp});");
+
         foreach (var initializer in structInitializerNode.Initializers)
         {
             var value = EmitExpression(initializer.Value);
-            initValues.Add($".{initializer.Key.Value} = {value}");
+            _writer.WriteLine($"{tmp}.{initializer.Key} = {value};");
         }
 
-        var initString = initValues.Count == 0
+        return tmp;
-            ? "0"
-            : string.Join(", ", initValues);
-
-        return $"({CType.Create(structInitializerNode.Type)}){{{initString}}}";
     }
 
     private string EmitI8Literal(I8LiteralNode i8LiteralNode)
@@ -580,17 +647,45 @@ public class Generator
 
     private void EmitBlock(BlockNode blockNode)
     {
-        _deferStack.Push([]);
-
         foreach (var statementNode in blockNode.Statements)
         {
             EmitStatement(statementNode);
         }
+    }
 
-        var blockDefers = _deferStack.Pop();
+    private void EmitScopeCleanup()
-        for (var i = blockDefers.Count - 1; i >= 0; i--)
     {
-            EmitStatement(blockDefers[i].Statement);
+        var deferredStack = Scope.GetDeferred();
+        while (deferredStack.TryPop(out var deferred))
+        {
+            deferred.Invoke();
+        }
+    }
+
+    private ScopeDisposer BeginScope()
+    {
+        _scopes.Push(new Scope());
+        return new ScopeDisposer(this);
+    }
+
+    private sealed class ScopeDisposer(Generator owner) : IDisposable
+    {
+        public void Dispose()
+        {
+            owner.EmitScopeCleanup();
+            owner._scopes.Pop();
         }
     }
 }
+
+public class Scope
+{
+    private readonly List<Action> _deferred = [];
+
+    public void Defer(Action action)
+    {
+        _deferred.Add(action);
+    }
+
+    public Stack<Action> GetDeferred() => new(_deferred);
+}

compiler/NubLang/Generation/HeaderGenerator.cs

@@ -0,0 +1,49 @@
+using NubLang.Ast;
+using NubLang.Syntax;
+
+namespace NubLang.Generation;
+
+public static class HeaderGenerator
+{
+    private static string FuncName(string module, string name, string? externSymbol)
+    {
+        return externSymbol ?? $"{module}_{name}";
+    }
+
+    public static string Generate(string name, TypedModule module)
+    {
+        var writer = new IndentedTextWriter();
+
+        writer.WriteLine();
+
+        foreach (var structType in module.StructTypes)
+        {
+            writer.WriteLine("typedef struct");
+            writer.WriteLine("{");
+            using (writer.Indent())
+            {
+                foreach (var field in structType.Fields)
+                {
+                    writer.WriteLine($"{CType.Create(field.Type)} {field.Name};");
+                }
+            }
+
+            writer.WriteLine($"}} {CType.Create(structType)};");
+            writer.WriteLine($"void {CType.Create(structType)}_create({CType.Create(structType)} *self);");
+            writer.WriteLine($"void {CType.Create(structType)}_destroy({CType.Create(structType)} *self);");
+            writer.WriteLine();
+        }
+
+        foreach (var prototype in module.FunctionPrototypes)
+        {
+            var parameters = prototype.Parameters.Count != 0
+                ? string.Join(", ", prototype.Parameters.Select(x => CType.Create(x.Type, x.NameToken.Value)))
+                : "void";
+
+            var funcName = FuncName(name, prototype.NameToken.Value, prototype.ExternSymbolToken?.Value);
+            writer.WriteLine($"{CType.Create(prototype.ReturnType, funcName)}({parameters});");
+        }
+
+        return writer.ToString();
+    }
+}

compiler/NubLang/Syntax/Parser.cs

@@ -45,7 +45,7 @@ public sealed class Parser
                     Symbol.Func => ParseFunc(startIndex, exported, null),
                     Symbol.Struct => ParseStruct(startIndex, exported),
                     Symbol.Enum => ParseEnum(startIndex, exported),
-                    _ => throw new ParseException(Diagnostic
+                    _ => throw new CompileException(Diagnostic
                         .Error($"Expected 'func', 'struct', 'enum', 'import' or 'module' but found '{keyword.Symbol}'")
                         .WithHelp("Valid top level statements are 'func', 'struct', 'enum', 'import' and 'module'")
                         .At(keyword)
@@ -54,7 +54,7 @@ public sealed class Parser
 
                 topLevelSyntaxNodes.Add(definition);
             }
-            catch (ParseException e)
+            catch (CompileException e)
             {
                 Diagnostics.Add(e.Diagnostic);
                 while (HasToken)
@@ -180,7 +180,7 @@ public sealed class Parser
             {
                 if (!TryExpectIntLiteral(out var intLiteralToken))
                 {
-                    throw new ParseException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("Value of enum field must be an integer literal")
                         .At(CurrentToken)
                         .Build());
@@ -451,13 +451,13 @@ public sealed class Parser
                 Symbol.OpenBrace => new StructInitializerSyntax(GetTokens(startIndex), null, ParseStructInitializerBody()),
                 Symbol.Struct => ParseStructInitializer(startIndex),
                 Symbol.At => ParseBuiltinFunction(startIndex),
-                _ => throw new ParseException(Diagnostic
+                _ => throw new CompileException(Diagnostic
                     .Error($"Unexpected symbol '{symbolToken.Symbol}' in expression")
                     .WithHelp("Expected '(', '-', '!', '[' or '{'")
                     .At(symbolToken)
                     .Build())
             },
-            _ => throw new ParseException(Diagnostic
+            _ => throw new CompileException(Diagnostic
                 .Error($"Unexpected token '{token.GetType().Name}' in expression")
                 .WithHelp("Expected literal, identifier, or parenthesized expression")
                 .At(token)
@@ -488,7 +488,7 @@ public sealed class Parser
             }
             default:
             {
-                throw new ParseException(Diagnostic.Error($"Unknown builtin {name.Value}").At(name).Build());
+                throw new CompileException(Diagnostic.Error($"Unknown builtin {name.Value}").At(name).Build());
             }
         }
     }
@@ -628,7 +628,7 @@ public sealed class Parser
             {
                 statements.Add(ParseStatement());
             }
-            catch (ParseException ex)
+            catch (CompileException ex)
             {
                 Diagnostics.Add(ex.Diagnostic);
                 if (HasToken)
@@ -654,7 +654,7 @@ public sealed class Parser
             {
                 if (size is not 8 and not 16 and not 32 and not 64)
                 {
-                    throw new ParseException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("Arbitrary uint size is not supported")
                         .WithHelp("Use u8, u16, u32 or u64")
                         .At(name)
@@ -668,7 +668,7 @@ public sealed class Parser
             {
                 if (size is not 8 and not 16 and not 32 and not 64)
                 {
-                    throw new ParseException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("Arbitrary int size is not supported")
                         .WithHelp("Use i8, i16, i32 or i64")
                         .At(name)
@@ -682,7 +682,7 @@ public sealed class Parser
             {
                 if (size is not 32 and not 64)
                 {
-                    throw new ParseException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("Arbitrary float size is not supported")
                         .WithHelp("Use f32 or f64")
                         .At(name)
@@ -716,6 +716,12 @@ public sealed class Parser
             }
         }
 
+        if (TryExpectSymbol(Symbol.Ampersand))
+        {
+            var baseType = ParseType();
+            return new RefTypeSyntax(GetTokens(startIndex), baseType);
+        }
+
         if (TryExpectSymbol(Symbol.Caret))
         {
             var baseType = ParseType();
@@ -766,7 +772,7 @@ public sealed class Parser
             }
         }
 
-        throw new ParseException(Diagnostic
+        throw new CompileException(Diagnostic
             .Error("Invalid type syntax")
             .WithHelp("Expected type name, '^' for pointer, or '[]' for array")
             .At(CurrentToken)
@@ -777,7 +783,7 @@ public sealed class Parser
     {
         if (!HasToken)
         {
-            throw new ParseException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error("Unexpected end of file")
                 .WithHelp("Expected more tokens to complete the syntax")
                 .At(_tokens[^1])
@@ -794,7 +800,7 @@ public sealed class Parser
         var token = ExpectToken();
         if (token is not SymbolToken symbol)
         {
-            throw new ParseException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error($"Expected symbol, but found {token.GetType().Name}")
                 .WithHelp("This position requires a symbol like '(', ')', '{', '}', etc.")
                 .At(token)
@@ -809,7 +815,7 @@ public sealed class Parser
         var token = ExpectSymbol();
         if (token.Symbol != expectedSymbol)
         {
-            throw new ParseException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error($"Expected '{expectedSymbol}', but found '{token.Symbol}'")
                 .WithHelp($"Insert '{expectedSymbol}' here")
                 .At(token)
@@ -859,7 +865,7 @@ public sealed class Parser
         var token = ExpectToken();
         if (token is not IdentifierToken identifier)
         {
-            throw new ParseException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error($"Expected identifier, but found {token.GetType().Name}")
                 .WithHelp("Provide a valid identifier name here")
                 .At(token)
@@ -887,7 +893,7 @@ public sealed class Parser
         var token = ExpectToken();
         if (token is not StringLiteralToken identifier)
         {
-            throw new ParseException(Diagnostic
+            throw new CompileException(Diagnostic
                 .Error($"Expected string literal, but found {token.GetType().Name}")
                 .WithHelp("Provide a valid string literal")
                 .At(token)
@@ -909,13 +915,3 @@ public sealed class Parser
 }
 
 public record SyntaxTree(List<TopLevelSyntaxNode> TopLevelSyntaxNodes);
-
-public class ParseException : Exception
-{
-    public Diagnostic Diagnostic { get; }
-
-    public ParseException(Diagnostic diagnostic) : base(diagnostic.Message)
-    {
-        Diagnostic = diagnostic;
-    }
-}

compiler/NubLang/Syntax/Syntax.cs

@@ -150,4 +150,6 @@ public record ConstArrayTypeSyntax(List<Token> Tokens, TypeSyntax BaseType, ulon
 
 public record CustomTypeSyntax(List<Token> Tokens, IdentifierToken? ModuleToken, IdentifierToken NameToken) : TypeSyntax(Tokens);
 
+public record RefTypeSyntax(List<Token> Tokens, TypeSyntax BaseType) : TypeSyntax(Tokens);
+
 #endregion

compiler/NubLang/Syntax/Tokenizer.cs

@@ -58,7 +58,7 @@ public sealed class Tokenizer
 
                 Tokens.Add(ParseToken(current, _line, _column));
             }
-            catch (TokenizerException e)
+            catch (CompileException e)
             {
                 Diagnostics.Add(e.Diagnostic);
                 Next();
@@ -95,7 +95,7 @@ public sealed class Tokenizer
             return ParseIdentifier(lineStart, columnStart);
         }
 
-        throw new TokenizerException(Diagnostic.Error($"Unknown token '{current}'").Build());
+        throw new CompileException(Diagnostic.Error($"Unknown token '{current}'").Build());
     }
 
     private Token ParseNumber(int lineStart, int columnStart)
@@ -116,7 +116,7 @@ public sealed class Tokenizer
 
             if (_index == digitStart)
             {
-                throw new TokenizerException(Diagnostic
+                throw new CompileException(Diagnostic
                     .Error("Invalid hex literal, no digits found")
                     .At(_fileName, _line, _column)
                     .Build());
@@ -141,7 +141,7 @@ public sealed class Tokenizer
 
             if (_index == digitStart)
             {
-                throw new TokenizerException(Diagnostic
+                throw new CompileException(Diagnostic
                     .Error("Invalid binary literal, no digits found")
                     .At(_fileName, _line, _column)
                     .Build());
@@ -163,7 +163,7 @@ public sealed class Tokenizer
             {
                 if (isFloat)
                 {
-                    throw new TokenizerException(Diagnostic
+                    throw new CompileException(Diagnostic
                         .Error("More than one period found in float literal")
                         .At(_fileName, _line, _column)
                         .Build());
@@ -198,7 +198,7 @@ public sealed class Tokenizer
         {
             if (_index >= _content.Length)
             {
-                throw new TokenizerException(Diagnostic
+                throw new CompileException(Diagnostic
                     .Error("Unclosed string literal")
                     .At(_fileName, _line, _column)
                     .Build());
@@ -208,7 +208,7 @@ public sealed class Tokenizer
 
             if (next == '\n')
             {
-                throw new TokenizerException(Diagnostic
+                throw new CompileException(Diagnostic
                     .Error("Unclosed string literal (newline found)")
                     .At(_fileName, _line, _column)
                     .Build());
@@ -376,13 +376,3 @@ public sealed class Tokenizer
         _column += count;
     }
 }
-
-public class TokenizerException : Exception
-{
-    public Diagnostic Diagnostic { get; }
-
-    public TokenizerException(Diagnostic diagnostic) : base(diagnostic.Message)
-    {
-        Diagnostic = diagnostic;
-    }
-}

compiler/NubLang/Syntax/TypedModule.cs

@@ -0,0 +1,50 @@
+using NubLang.Ast;
+
+namespace NubLang.Syntax;
+
+public sealed class TypedModule
+{
+    public static TypedModule FromModule(string name, Module module, Dictionary<string, Module> modules)
+    {
+        var typeResolver = new TypeResolver(modules);
+
+        var functionPrototypes = new List<FuncPrototypeNode>();
+
+        foreach (var funcSyntax in module.Functions(true))
+        {
+            var parameters = new List<FuncParameterNode>();
+            foreach (var parameter in funcSyntax.Prototype.Parameters)
+            {
+                parameters.Add(new FuncParameterNode(parameter.Tokens, parameter.NameToken, typeResolver.ResolveType(parameter.Type, name)));
+            }
+
+            var returnType = typeResolver.ResolveType(funcSyntax.Prototype.ReturnType, name);
+
+            functionPrototypes.Add(new FuncPrototypeNode(funcSyntax.Tokens, funcSyntax.Prototype.NameToken, funcSyntax.Prototype.ExternSymbolToken, parameters, returnType));
+        }
+
+        var structTypes = new List<NubStructType>();
+
+        foreach (var structSyntax in module.Structs(true))
+        {
+            var fields = new List<NubStructFieldType>();
+            foreach (var field in structSyntax.Fields)
+            {
+                fields.Add(new NubStructFieldType(field.NameToken.Value, typeResolver.ResolveType(field.Type, name), field.Value != null));
+            }
+
+            structTypes.Add(new NubStructType(name, structSyntax.NameToken.Value, fields));
+        }
+
+        return new TypedModule(functionPrototypes, structTypes);
+    }
+
+    public TypedModule(List<FuncPrototypeNode> functionPrototypes, List<NubStructType> structTypes)
+    {
+        FunctionPrototypes = functionPrototypes;
+        StructTypes = structTypes;
+    }
+
+    public List<FuncPrototypeNode> FunctionPrototypes { get; set; }
+    public List<NubStructType> StructTypes { get; set; }
+}

examples/playgroud/build.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+set -euo pipefail
+
+obj=$(nubc main.nub)
+clang $obj ../../runtime/.build/runtime.o -o .build/out

examples/playgroud/main.nub

@@ -0,0 +1,45 @@
+module main
+
+extern "puts" func puts(text: ^i8)
+
+struct Name
+{
+    first: ^i8
+    last: ^i8
+}
+
+struct Human
+{
+    age: u64
+    name: &Name
+}
+
+extern "main" func main(argc: i64, argv: [?]^i8): i64
+{
+    let x: &Human = {
+        age = 23
+        name = {
+            first = "oliver"
+            last = "stene"
+        }
+    }
+
+    let z: Human = {
+        age = 23
+        name = {
+            first = "oliver"
+            last = "stene"
+        }
+    }
+
+    test(x)
+
+    let y = x
+
+    return 0
+}
+
+func test(x: &Human): &Human
+{
+    return x
+}

runtime/.gitignore

@@ -0,0 +1 @@
+.build

runtime/build.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+set -euo pipefail
+
+mkdir -p .build
+clang -c runtime.c -o .build/runtime.o

runtime/ref.c

@@ -0,0 +1,42 @@
+#include "ref.h"
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+void *rc_alloc(size_t size, void (*destructor)(void *self))
+{
+    printf("rc_alloc %zu bytes\n", size);
+    ref_header *header = malloc(sizeof(ref_header) + size);
+    if (!header)
+    {
+        exit(69);
+    }
+
+    header->ref_count = 1;
+    header->destructor = destructor;
+
+    return (void *)(header + 1);
+}
+
+void rc_retain(void *obj)
+{
+    printf("rc_retain\n");
+    ref_header *header = ((ref_header *)obj) - 1;
+    header->ref_count++;
+}
+
+void rc_release(void *obj)
+{
+    ref_header *header = ((ref_header *)obj) - 1;
+    printf("rc_release\n");
+    if (--header->ref_count == 0)
+    {
+        if (header->destructor)
+        {
+            header->destructor(obj);
+        }
+
+        free(header);
+        printf("rc_free\n");
+    }
+}

runtime/ref.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <stddef.h>
+
+typedef struct
+{
+    int ref_count;
+    void (*destructor)(void *self);
+} ref_header;
+
+void *rc_alloc(size_t size, void (*destructor)(void *self));
+void rc_retain(void *obj);
+void rc_release(void *obj);

runtime/runtime.c

@@ -0,0 +1 @@
+#include "ref.c"