compiler/Diagnostic.cs

@@ -1,29 +1,51 @@
 namespace Compiler;
 
-public sealed class Diagnostic(DiagnosticSeverity severity, string message, string? help, FileInfo? file)
+public class Diagnostic
 {
-    public static DiagnosticBuilder Info(string message) => new DiagnosticBuilder(DiagnosticSeverity.Info, message);
+    public static Builder Info(string message) => new Builder(DiagnosticSeverity.Info, message);
-    public static DiagnosticBuilder Warning(string message) => new DiagnosticBuilder(DiagnosticSeverity.Warning, message);
+    public static Builder Warning(string message) => new Builder(DiagnosticSeverity.Warning, message);
-    public static DiagnosticBuilder Error(string message) => new DiagnosticBuilder(DiagnosticSeverity.Error, message);
+    public static Builder Error(string message) => new Builder(DiagnosticSeverity.Error, message);
 
-    public DiagnosticSeverity Severity { get; } = severity;
+    private Diagnostic(DiagnosticSeverity severity, string message, string? help, FileInfo? file)
-    public string Message { get; } = message;
+    {
-    public string? Help { get; } = help;
+        Severity = severity;
-    public FileInfo? File { get; } = file;
+        Message = message;
+        Help = help;
+        File = file;
     }
 
-public sealed class DiagnosticBuilder(DiagnosticSeverity severity, string message)
+    public class FileInfo(string file, int line, int column, int length)
+    {
+        public string File { get; } = file;
+        public int Line { get; } = line;
+        public int Column { get; } = column;
+        public int Length { get; } = length;
+    }
+
+    public DiagnosticSeverity Severity { get; }
+    public string Message { get; }
+    public string? Help { get; }
+    public FileInfo? File { get; }
+
+    public enum DiagnosticSeverity
+    {
+        Info,
+        Warning,
+        Error,
+    }
+
+    public class Builder(DiagnosticSeverity severity, string message)
     {
         private FileInfo? file;
         private string? help;
 
-    public DiagnosticBuilder At(string fileName, int line, int column, int length)
+        public Builder At(string fileName, int line, int column, int length)
         {
             file = new FileInfo(fileName, line, column, length);
             return this;
         }
 
-    public DiagnosticBuilder At(string fileName, Token? token)
+        public Builder At(string fileName, Token? token)
         {
             if (token != null)
             {
@@ -33,7 +55,7 @@ public sealed class DiagnosticBuilder(DiagnosticSeverity severity, string messag
             return this;
         }
 
-    public DiagnosticBuilder At(string fileName, Node? node)
+        public Builder At(string fileName, Node? node)
         {
             if (node != null && node.Tokens.Count != 0)
             {
@@ -44,7 +66,7 @@ public sealed class DiagnosticBuilder(DiagnosticSeverity severity, string messag
             return this;
         }
 
-    public DiagnosticBuilder At(string fileName, TypedNode? node)
+        public Builder At(string fileName, TypedNode? node)
         {
             if (node != null && node.Tokens.Count != 0)
             {
@@ -55,7 +77,7 @@ public sealed class DiagnosticBuilder(DiagnosticSeverity severity, string messag
             return this;
         }
 
-    public DiagnosticBuilder WithHelp(string helpMessage)
+        public Builder WithHelp(string helpMessage)
         {
             help = helpMessage;
             return this;
@@ -66,23 +88,9 @@ public sealed class DiagnosticBuilder(DiagnosticSeverity severity, string messag
             return new Diagnostic(severity, message, help, file);
         }
     }
-
-public sealed class FileInfo(string file, int line, int column, int length)
-{
-    public string File { get; } = file;
-    public int Line { get; } = line;
-    public int Column { get; } = column;
-    public int Length { get; } = length;
 }
 
-public enum DiagnosticSeverity
+public class CompileException(Diagnostic diagnostic) : Exception
-{
-    Info,
-    Warning,
-    Error,
-}
-
-public sealed class CompileException(Diagnostic diagnostic) : Exception
 {
     public Diagnostic Diagnostic { get; } = diagnostic;
 }
@@ -93,9 +101,9 @@ public static class DiagnosticFormatter
     {
         var (label, color) = diagnostic.Severity switch
         {
-            DiagnosticSeverity.Info => ("info", Ansi.Cyan),
+            Diagnostic.DiagnosticSeverity.Info => ("info", Ansi.Cyan),
-            DiagnosticSeverity.Warning => ("warning", Ansi.Yellow),
+            Diagnostic.DiagnosticSeverity.Warning => ("warning", Ansi.Yellow),
-            DiagnosticSeverity.Error => ("error", Ansi.Red),
+            Diagnostic.DiagnosticSeverity.Error => ("error", Ansi.Red),
             _ => ("unknown", Ansi.Reset),
         };
 

compiler/Generator.cs

@@ -2,13 +2,23 @@
 
 namespace Compiler;
 
-public sealed class Generator(List<TypedNodeDefinitionFunc> functions, ModuleGraph moduleGraph, bool compileLib)
+public class Generator
 {
     public static string Emit(List<TypedNodeDefinitionFunc> functions, ModuleGraph moduleGraph, bool compileLib)
     {
         return new Generator(functions, moduleGraph, compileLib).Emit();
     }
 
+    private Generator(List<TypedNodeDefinitionFunc> functions, ModuleGraph moduleGraph, bool compileLib)
+    {
+        this.functions = functions;
+        this.moduleGraph = moduleGraph;
+        this.compileLib = compileLib;
+    }
+
+    private readonly List<TypedNodeDefinitionFunc> functions;
+    private readonly ModuleGraph moduleGraph;
+    private readonly bool compileLib;
     private readonly IndentedTextWriter writer = new();
     private readonly Dictionary<NubTypeStruct, string> structTypeNames = new();
 

compiler/ModuleGraph.cs

@@ -3,9 +3,16 @@ using System.Diagnostics.CodeAnalysis;
 
 namespace Compiler;
 
-public class ModuleGraph(Dictionary<string, ModuleGraph.Module> modules)
+public class ModuleGraph
 {
-    public static Builder Create() => new();
+    public static Builder CreateBuilder() => new();
+
+    private ModuleGraph(Dictionary<string, Module> modules)
+    {
+        this.modules = modules;
+    }
+
+    private readonly Dictionary<string, Module> modules;
 
     public List<Module> GetModules()
     {
@@ -23,7 +30,7 @@ public class ModuleGraph(Dictionary<string, ModuleGraph.Module> modules)
         return new Manifest(1, GetModules().Select(x => x.CreateManifestModule()).ToList());
     }
 
-    public sealed class Module(string name)
+    public class Module(string name)
     {
         public string Name { get; } = name;
         private readonly Dictionary<string, CustomTypeInfo> customTypes = new();
@@ -108,7 +115,7 @@ public class ModuleGraph(Dictionary<string, ModuleGraph.Module> modules)
 
             public ManifestCustomTypeInfo CreateManifestCustomTypeInfo()
             {
-                return new ManifestCustomTypeInfo(TypeMangler.Encode(Type), Exported);
+                return new ManifestCustomTypeInfo(TypeEncoder.Encode(Type), Exported);
             }
         }
 
@@ -120,7 +127,7 @@ public class ModuleGraph(Dictionary<string, ModuleGraph.Module> modules)
 
             public ManifestIdentifierInfo CreateManifestIdentifierInfo()
             {
-                return new ManifestIdentifierInfo(TypeMangler.Encode(Type), Exported);
+                return new ManifestIdentifierInfo(TypeEncoder.Encode(Type), Exported);
             }
         }
     }
@@ -159,13 +166,13 @@ public class ModuleGraph(Dictionary<string, ModuleGraph.Module> modules)
 
                     foreach (var customType in manifestModule.CustomTypes)
                     {
-                        var decoded = TypeMangler.Decode(customType.Value.EncodedType);
+                        var decoded = TypeDecoder.Decode(customType.Value.EncodedType);
                         module.AddCustomType(customType.Key, new Module.CustomTypeInfo(decoded, customType.Value.Exported, Module.Source.Lib));
                     }
 
                     foreach (var identifier in manifestModule.Identifiers)
                     {
-                        var decoded = TypeMangler.Decode(identifier.Value.EncodedType);
+                        var decoded = TypeDecoder.Decode(identifier.Value.EncodedType);
                         module.AddIdentifier(identifier.Key, new Module.IdentifierInfo(decoded, identifier.Value.Exported, Module.Source.Lib));
                     }
                 }
@@ -234,7 +241,7 @@ public class ModuleGraph(Dictionary<string, ModuleGraph.Module> modules)
                 }
             }
 
-            if (diagnostics.Any(x => x.Severity == DiagnosticSeverity.Error))
+            if (diagnostics.Any(x => x.Severity == Diagnostic.DiagnosticSeverity.Error))
                 return null;
 
             return new ModuleGraph(modules);

compiler/NubType.cs

@@ -1,4 +1,3 @@
-using System.Net;
 using System.Text;
 
 namespace Compiler;
@@ -8,7 +7,7 @@ public abstract class NubType
     public abstract override string ToString();
 }
 
-public sealed class NubTypeVoid : NubType
+public class NubTypeVoid : NubType
 {
     public static readonly NubTypeVoid Instance = new();
 
@@ -19,7 +18,7 @@ public sealed class NubTypeVoid : NubType
     public override string ToString() => "void";
 }
 
-public sealed class NubTypeUInt : NubType
+public class NubTypeUInt : NubType
 {
     private static readonly Dictionary<int, NubTypeUInt> Cache = new();
 
@@ -41,7 +40,7 @@ public sealed class NubTypeUInt : NubType
     public override string ToString() => $"u{Width}";
 }
 
-public sealed class NubTypeSInt : NubType
+public class NubTypeSInt : NubType
 {
     private static readonly Dictionary<int, NubTypeSInt> Cache = new();
 
@@ -63,7 +62,7 @@ public sealed class NubTypeSInt : NubType
     public override string ToString() => $"i{Width}";
 }
 
-public sealed class NubTypeBool : NubType
+public class NubTypeBool : NubType
 {
     public static readonly NubTypeBool Instance = new();
 
@@ -74,7 +73,7 @@ public sealed class NubTypeBool : NubType
     public override string ToString() => "bool";
 }
 
-public sealed class NubTypeString : NubType
+public class NubTypeString : NubType
 {
     public static readonly NubTypeString Instance = new();
 
@@ -85,7 +84,7 @@ public sealed class NubTypeString : NubType
     public override string ToString() => "string";
 }
 
-public sealed class NubTypeStruct : NubType
+public class NubTypeStruct : NubType
 {
     public string Name { get; }
     public string Module { get; }
@@ -112,14 +111,14 @@ public sealed class NubTypeStruct : NubType
 
     public override string ToString() => _resolvedFields == null ? $"struct {Module}::{Name} <unresolved>" : $"struct {Module}::{Name} {{ {string.Join(' ', Fields.Select(f => $"{f.Name}: {f.Type}"))} }}";
 
-    public sealed class Field(string name, NubType type)
+    public class Field(string name, NubType type)
     {
         public string Name { get; } = name;
         public NubType Type { get; } = type;
     }
 }
 
-public sealed class NubTypePointer : NubType
+public class NubTypePointer : NubType
 {
     private static readonly Dictionary<NubType, NubTypePointer> Cache = new();
 
@@ -141,7 +140,7 @@ public sealed class NubTypePointer : NubType
     public override string ToString() => $"^{To}";
 }
 
-public sealed class NubTypeFunc : NubType
+public class NubTypeFunc : NubType
 {
     private static readonly Dictionary<Signature, NubTypeFunc> Cache = new();
 
@@ -171,7 +170,7 @@ public sealed class NubTypeFunc : NubType
     private readonly record struct Signature(IReadOnlyList<NubType> Parameters, NubType ReturnType);
 }
 
-static class TypeMangler
+static class TypeEncoder
 {
     public static string Encode(NubType type)
     {
@@ -241,63 +240,78 @@ static class TypeMangler
                 throw new NotSupportedException(type.GetType().Name);
         }
     }
-
-    public static NubType Decode(string encoded)
-    {
-        int pos = 0;
-        return Parse(encoded, ref pos);
 }
 
-    private static NubType Parse(string s, ref int pos)
+class TypeDecoder
 {
-        if (pos >= s.Length)
+    public static NubType Decode(string encoded)
+    {
+        return new TypeDecoder(encoded).Decode();
+    }
+
+    private TypeDecoder(string encoded)
+    {
+        this.encoded = encoded;
+    }
+
+    private readonly string encoded;
+    private int pos;
+
+    private NubType Decode()
+    {
+        return Parse();
+    }
+
+    private NubType Parse()
+    {
+        if (pos >= encoded.Length)
             throw new InvalidOperationException("Unexpected end of string");
 
-        char c = s[pos++];
+        char c = encoded[pos++];
         return c switch
         {
             'V' => NubTypeVoid.Instance,
             'B' => NubTypeBool.Instance,
             'S' => NubTypeString.Instance,
-            'U' => ParseUInt(s, ref pos),
+            'U' => ParseUInt(),
-            'I' => ParseSInt(s, ref pos),
+            'I' => ParseSInt(),
-            'P' => ParsePointer(s, ref pos),
+            'P' => ParsePointer(),
-            'T' => ParseStruct(s, ref pos),
+            'T' => ParseStruct(),
-            'F' => ParseFunc(s, ref pos),
+            'F' => ParseFunc(),
             _ => throw new NotSupportedException($"Unknown type code '{c}' at position {pos - 1}")
         };
     }
 
-    private static NubTypeUInt ParseUInt(string s, ref int pos)
+    private NubTypeUInt ParseUInt()
     {
-        ExpectChar(s, ref pos, '(');
+        ExpectChar('(');
-        int width = ReadNumber(s, ref pos);
+        int width = ReadNumber();
-        ExpectChar(s, ref pos, ')');
+        ExpectChar(')');
         return NubTypeUInt.Get(width);
     }
 
-    private static NubTypeSInt ParseSInt(string s, ref int pos)
+    private NubTypeSInt ParseSInt()
     {
-        ExpectChar(s, ref pos, '(');
+        ExpectChar('(');
-        int width = ReadNumber(s, ref pos);
+        int width = ReadNumber();
-        ExpectChar(s, ref pos, ')');
+        ExpectChar(')');
         return NubTypeSInt.Get(width);
     }
 
-    private static NubTypePointer ParsePointer(string s, ref int pos)
+    private NubTypePointer ParsePointer()
     {
-        ExpectChar(s, ref pos, '(');
+        ExpectChar('(');
-        var to = Parse(s, ref pos);
+        var to = Parse();
-        ExpectChar(s, ref pos, ')');
+        ExpectChar(')');
         return NubTypePointer.Get(to);
     }
 
-    private static NubTypeStruct ParseStruct(string s, ref int pos)
+    private NubTypeStruct ParseStruct()
     {
-        ExpectChar(s, ref pos, '(');
+        ExpectChar('(');
         int start = pos;
-        while (pos < s.Length && s[pos] != ',' && s[pos] != '{') pos++;
+        while (pos < encoded.Length && encoded[pos] != ',' && encoded[pos] != '{') pos++;
-        var fullName = s[start..pos];
+        var fullName = encoded[start..pos];
         var parts = fullName.Split("::");
         if (parts.Length != 2)
             throw new InvalidOperationException($"Invalid struct name: {fullName}");
@@ -305,64 +319,64 @@ static class TypeMangler
         string module = parts[0], name = parts[1];
 
         bool packed = false;
-        if (s[pos] == ',')
+        if (encoded[pos] == ',')
         {
             pos += 1;
-            packed = s[pos += 1] == '1';
+            packed = encoded[pos += 1] == '1';
         }
 
         var st = new NubTypeStruct(module, name, packed);
 
-        ExpectChar(s, ref pos, '{');
+        ExpectChar('{');
 
         var fields = new List<NubTypeStruct.Field>();
-        while (s[pos] != '}')
+        while (encoded[pos] != '}')
         {
             int nameStart = pos;
-            while (s[pos] != ':') pos += 1;
+            while (encoded[pos] != ':') pos += 1;
-            string fieldName = s[nameStart..pos];
+            string fieldName = encoded[nameStart..pos];
             pos += 1;
 
-            var fieldType = Parse(s, ref pos);
+            var fieldType = Parse();
             fields.Add(new NubTypeStruct.Field(fieldName, fieldType));
 
-            if (s[pos] == ',') pos += 1;
+            if (encoded[pos] == ',') pos += 1;
         }
 
-        ExpectChar(s, ref pos, '}');
+        ExpectChar('}');
-        ExpectChar(s, ref pos, ')');
+        ExpectChar(')');
 
         st.ResolveFields(fields);
         return st;
     }
 
-    private static NubTypeFunc ParseFunc(string s, ref int pos)
+    private NubTypeFunc ParseFunc()
     {
-        ExpectChar(s, ref pos, '(');
+        ExpectChar('(');
         var parameters = new List<NubType>();
         while (true)
         {
-            if (s[pos] == ')')
+            if (encoded[pos] == ')')
             {
                 pos++;
                 break;
             }
 
-            var param = Parse(s, ref pos);
+            var param = Parse();
             parameters.Add(param);
 
-            if (s[pos] == ',')
+            if (encoded[pos] == ',')
             {
                 pos += 1;
             }
-            else if (s[pos] == ')')
+            else if (encoded[pos] == ')')
             {
                 pos += 1;
                 break;
             }
             else
             {
-                throw new InvalidOperationException($"Unexpected char '{s[pos]}' in function type at {pos}");
+                throw new InvalidOperationException($"Unexpected char '{encoded[pos]}' in function type at {pos}");
             }
         }
 
@@ -375,20 +389,20 @@ static class TypeMangler
         return NubTypeFunc.Get(paramTypes, returnType);
     }
 
-    private static void ExpectChar(string s, ref int pos, char expected)
+    private void ExpectChar(char expected)
     {
-        if (pos >= s.Length || s[pos] != expected)
+        if (pos >= encoded.Length || encoded[pos] != expected)
             throw new InvalidOperationException($"Expected '{expected}' at position {pos}");
 
         pos += 1;
     }
 
-    private static int ReadNumber(string s, ref int pos)
+    private int ReadNumber()
     {
         int start = pos;
-        while (pos < s.Length && char.IsDigit(s[pos])) pos += 1;
+        while (pos < encoded.Length && char.IsDigit(encoded[pos])) pos += 1;
         if (start == pos) throw new InvalidOperationException($"Expected number at position {start}");
-        return int.Parse(s[start..pos]);
+        return int.Parse(encoded[start..pos]);
     }
 }
 
@@ -414,7 +428,7 @@ static class SymbolNameGen
 {
     public static string Exported(string module, string function, NubType type)
     {
-        var canonical = TypeMangler.Encode(type);
+        var canonical = TypeEncoder.Encode(type);
         var hash = Hashing.Fnv1a64(canonical);
 
         return $"nub_{Sanitize(module)}_{Sanitize(function)}_{hash:x16}";

compiler/Parser.cs

@@ -2,13 +2,21 @@
 
 namespace Compiler;
 
-public sealed class Parser(string fileName, List<Token> tokens)
+public class Parser
 {
     public static Ast? Parse(string fileName, List<Token> tokens, out List<Diagnostic> diagnostics)
     {
         return new Parser(fileName, tokens).Parse(out diagnostics);
     }
 
+    private Parser(string fileName, List<Token> tokens)
+    {
+        this.fileName = fileName;
+        this.tokens = tokens;
+    }
+
+    private readonly string fileName;
+    private readonly List<Token> tokens;
     private int index;
 
     private Ast? Parse(out List<Diagnostic> diagnostics)
@@ -33,7 +41,7 @@ public sealed class Parser(string fileName, List<Token> tokens)
             diagnostics.Add(e.Diagnostic);
         }
 
-        if (moduleName == null || diagnostics.Any(x => x.Severity == DiagnosticSeverity.Error))
+        if (moduleName == null || diagnostics.Any(x => x.Severity == Diagnostic.DiagnosticSeverity.Error))
             return null;
 
         return new Ast(fileName, moduleName, definitions);
@@ -594,7 +602,7 @@ public sealed class Parser(string fileName, List<Token> tokens)
     }
 }
 
-public sealed class Ast(string fileName, TokenIdent moduleName, List<NodeDefinition> definitions)
+public class Ast(string fileName, TokenIdent moduleName, List<NodeDefinition> definitions)
 {
     public string FileName { get; } = fileName;
     public TokenIdent ModuleName { get; } = moduleName;
@@ -608,7 +616,7 @@ public abstract class Node(List<Token> tokens)
 
 public abstract class NodeDefinition(List<Token> tokens) : Node(tokens);
 
-public sealed class NodeDefinitionFunc(List<Token> tokens, bool exported, TokenIdent name, List<NodeDefinitionFunc.Param> parameters, NodeStatement body, NodeType returnType) : NodeDefinition(tokens)
+public class NodeDefinitionFunc(List<Token> tokens, bool exported, TokenIdent name, List<NodeDefinitionFunc.Param> parameters, NodeStatement body, NodeType returnType) : NodeDefinition(tokens)
 {
     public bool Exported { get; } = exported;
     public TokenIdent Name { get; } = name;
@@ -616,28 +624,28 @@ public sealed class NodeDefinitionFunc(List<Token> tokens, bool exported, TokenI
     public NodeStatement Body { get; } = body;
     public NodeType ReturnType { get; } = returnType;
 
-    public sealed class Param(List<Token> tokens, TokenIdent name, NodeType type) : Node(tokens)
+    public class Param(List<Token> tokens, TokenIdent name, NodeType type) : Node(tokens)
     {
         public TokenIdent Name { get; } = name;
         public NodeType Type { get; } = type;
     }
 }
 
-public sealed class NodeDefinitionStruct(List<Token> tokens, bool exported, bool packed, TokenIdent name, List<NodeDefinitionStruct.Field> fields) : NodeDefinition(tokens)
+public class NodeDefinitionStruct(List<Token> tokens, bool exported, bool packed, TokenIdent name, List<NodeDefinitionStruct.Field> fields) : NodeDefinition(tokens)
 {
     public bool Exported { get; } = exported;
     public bool Packed { get; } = packed;
     public TokenIdent Name { get; } = name;
     public List<Field> Fields { get; } = fields;
 
-    public sealed class Field(List<Token> tokens, TokenIdent name, NodeType type) : Node(tokens)
+    public class Field(List<Token> tokens, TokenIdent name, NodeType type) : Node(tokens)
     {
         public TokenIdent Name { get; } = name;
         public NodeType Type { get; } = type;
     }
 }
 
-public sealed class NodeDefinitionGlobalVariable(List<Token> tokens, bool exported, TokenIdent name, NodeType type) : NodeDefinition(tokens)
+public class NodeDefinitionGlobalVariable(List<Token> tokens, bool exported, TokenIdent name, NodeType type) : NodeDefinition(tokens)
 {
     public bool Exported { get; } = exported;
     public TokenIdent Name { get; } = name;
@@ -646,42 +654,42 @@ public sealed class NodeDefinitionGlobalVariable(List<Token> tokens, bool export
 
 public abstract class NodeStatement(List<Token> tokens) : Node(tokens);
 
-public sealed class NodeStatementBlock(List<Token> tokens, List<NodeStatement> statements) : NodeStatement(tokens)
+public class NodeStatementBlock(List<Token> tokens, List<NodeStatement> statements) : NodeStatement(tokens)
 {
     public List<NodeStatement> Statements { get; } = statements;
 }
 
-public sealed class NodeStatementExpression(List<Token> tokens, NodeExpression expression) : NodeStatement(tokens)
+public class NodeStatementExpression(List<Token> tokens, NodeExpression expression) : NodeStatement(tokens)
 {
     public NodeExpression Expression { get; } = expression;
 }
 
-public sealed class NodeStatementReturn(List<Token> tokens, NodeExpression value) : NodeStatement(tokens)
+public class NodeStatementReturn(List<Token> tokens, NodeExpression value) : NodeStatement(tokens)
 {
     public NodeExpression Value { get; } = value;
 }
 
-public sealed class NodeStatementVariableDeclaration(List<Token> tokens, TokenIdent name, NodeType type, NodeExpression value) : NodeStatement(tokens)
+public class NodeStatementVariableDeclaration(List<Token> tokens, TokenIdent name, NodeType type, NodeExpression value) : NodeStatement(tokens)
 {
     public TokenIdent Name { get; } = name;
     public NodeType Type { get; } = type;
     public NodeExpression Value { get; } = value;
 }
 
-public sealed class NodeStatementAssignment(List<Token> tokens, NodeExpression target, NodeExpression value) : NodeStatement(tokens)
+public class NodeStatementAssignment(List<Token> tokens, NodeExpression target, NodeExpression value) : NodeStatement(tokens)
 {
     public NodeExpression Target { get; } = target;
     public NodeExpression Value { get; } = value;
 }
 
-public sealed class NodeStatementIf(List<Token> tokens, NodeExpression condition, NodeStatement thenBlock, NodeStatement? elseBlock) : NodeStatement(tokens)
+public class NodeStatementIf(List<Token> tokens, NodeExpression condition, NodeStatement thenBlock, NodeStatement? elseBlock) : NodeStatement(tokens)
 {
     public NodeExpression Condition { get; } = condition;
     public NodeStatement ThenBlock { get; } = thenBlock;
     public NodeStatement? ElseBlock { get; } = elseBlock;
 }
 
-public sealed class NodeStatementWhile(List<Token> tokens, NodeExpression condition, NodeStatement block) : NodeStatement(tokens)
+public class NodeStatementWhile(List<Token> tokens, NodeExpression condition, NodeStatement block) : NodeStatement(tokens)
 {
     public NodeExpression Condition { get; } = condition;
     public NodeStatement Block { get; } = block;
@@ -689,58 +697,58 @@ public sealed class NodeStatementWhile(List<Token> tokens, NodeExpression condit
 
 public abstract class NodeExpression(List<Token> tokens) : Node(tokens);
 
-public sealed class NodeExpressionIntLiteral(List<Token> tokens, TokenIntLiteral value) : NodeExpression(tokens)
+public class NodeExpressionIntLiteral(List<Token> tokens, TokenIntLiteral value) : NodeExpression(tokens)
 {
     public TokenIntLiteral Value { get; } = value;
 }
 
-public sealed class NodeExpressionStringLiteral(List<Token> tokens, TokenStringLiteral value) : NodeExpression(tokens)
+public class NodeExpressionStringLiteral(List<Token> tokens, TokenStringLiteral value) : NodeExpression(tokens)
 {
     public TokenStringLiteral Value { get; } = value;
 }
 
-public sealed class NodeExpressionBoolLiteral(List<Token> tokens, TokenBoolLiteral value) : NodeExpression(tokens)
+public class NodeExpressionBoolLiteral(List<Token> tokens, TokenBoolLiteral value) : NodeExpression(tokens)
 {
     public TokenBoolLiteral Value { get; } = value;
 }
 
-public sealed class NodeExpressionStructLiteral(List<Token> tokens, TokenIdent module, TokenIdent name, List<NodeExpressionStructLiteral.Initializer> initializers) : NodeExpression(tokens)
+public class NodeExpressionStructLiteral(List<Token> tokens, TokenIdent module, TokenIdent name, List<NodeExpressionStructLiteral.Initializer> initializers) : NodeExpression(tokens)
 {
     public TokenIdent Module { get; } = module;
     public TokenIdent Name { get; } = name;
     public List<Initializer> Initializers { get; } = initializers;
 
-    public sealed class Initializer(List<Token> tokens, TokenIdent name, NodeExpression value) : Node(tokens)
+    public class Initializer(List<Token> tokens, TokenIdent name, NodeExpression value) : Node(tokens)
     {
         public TokenIdent Name { get; } = name;
         public NodeExpression Value { get; } = value;
     }
 }
 
-public sealed class NodeExpressionMemberAccess(List<Token> tokens, NodeExpression target, TokenIdent name) : NodeExpression(tokens)
+public class NodeExpressionMemberAccess(List<Token> tokens, NodeExpression target, TokenIdent name) : NodeExpression(tokens)
 {
     public NodeExpression Target { get; } = target;
     public TokenIdent Name { get; } = name;
 }
 
-public sealed class NodeExpressionFuncCall(List<Token> tokens, NodeExpression target, List<NodeExpression> parameters) : NodeExpression(tokens)
+public class NodeExpressionFuncCall(List<Token> tokens, NodeExpression target, List<NodeExpression> parameters) : NodeExpression(tokens)
 {
     public NodeExpression Target { get; } = target;
     public List<NodeExpression> Parameters { get; } = parameters;
 }
 
-public sealed class NodeExpressionLocalIdent(List<Token> tokens, TokenIdent value) : NodeExpression(tokens)
+public class NodeExpressionLocalIdent(List<Token> tokens, TokenIdent value) : NodeExpression(tokens)
 {
     public TokenIdent Value { get; } = value;
 }
 
-public sealed class NodeExpressionModuleIdent(List<Token> tokens, TokenIdent module, TokenIdent value) : NodeExpression(tokens)
+public class NodeExpressionModuleIdent(List<Token> tokens, TokenIdent module, TokenIdent value) : NodeExpression(tokens)
 {
     public TokenIdent Module { get; } = module;
     public TokenIdent Value { get; } = value;
 }
 
-public sealed class NodeExpressionBinary(List<Token> tokens, NodeExpression left, NodeExpressionBinary.Op operation, NodeExpression right) : NodeExpression(tokens)
+public class NodeExpressionBinary(List<Token> tokens, NodeExpression left, NodeExpressionBinary.Op operation, NodeExpression right) : NodeExpression(tokens)
 {
     public NodeExpression Left { get; } = left;
     public Op Operation { get; } = operation;
@@ -773,7 +781,7 @@ public sealed class NodeExpressionBinary(List<Token> tokens, NodeExpression left
     }
 }
 
-public sealed class NodeExpressionUnary(List<Token> tokens, NodeExpression target, NodeExpressionUnary.Op op) : NodeExpression(tokens)
+public class NodeExpressionUnary(List<Token> tokens, NodeExpression target, NodeExpressionUnary.Op op) : NodeExpression(tokens)
 {
     public NodeExpression Target { get; } = target;
     public Op Operation { get; } = op;
@@ -787,34 +795,34 @@ public sealed class NodeExpressionUnary(List<Token> tokens, NodeExpression targe
 
 public abstract class NodeType(List<Token> tokens) : Node(tokens);
 
-public sealed class NodeTypeVoid(List<Token> tokens) : NodeType(tokens);
+public class NodeTypeVoid(List<Token> tokens) : NodeType(tokens);
 
-public sealed class NodeTypeUInt(List<Token> tokens, int width) : NodeType(tokens)
+public class NodeTypeUInt(List<Token> tokens, int width) : NodeType(tokens)
 {
     public int Width { get; } = width;
 }
 
-public sealed class NodeTypeSInt(List<Token> tokens, int width) : NodeType(tokens)
+public class NodeTypeSInt(List<Token> tokens, int width) : NodeType(tokens)
 {
     public int Width { get; } = width;
 }
 
-public sealed class NodeTypeBool(List<Token> tokens) : NodeType(tokens);
+public class NodeTypeBool(List<Token> tokens) : NodeType(tokens);
 
-public sealed class NodeTypeString(List<Token> tokens) : NodeType(tokens);
+public class NodeTypeString(List<Token> tokens) : NodeType(tokens);
 
-public sealed class NodeTypeCustom(List<Token> tokens, TokenIdent module, TokenIdent name) : NodeType(tokens)
+public class NodeTypeCustom(List<Token> tokens, TokenIdent module, TokenIdent name) : NodeType(tokens)
 {
     public TokenIdent Module { get; } = module;
     public TokenIdent Name { get; } = name;
 }
 
-public sealed class NodeTypePointer(List<Token> tokens, NodeType to) : NodeType(tokens)
+public class NodeTypePointer(List<Token> tokens, NodeType to) : NodeType(tokens)
 {
     public NodeType To { get; } = to;
 }
 
-public sealed class NodeTypeFunc(List<Token> tokens, List<NodeType> parameters, NodeType returnType) : NodeType(tokens)
+public class NodeTypeFunc(List<Token> tokens, List<NodeType> parameters, NodeType returnType) : NodeType(tokens)
 {
     public List<NodeType> Parameters { get; } = parameters;
     public NodeType ReturnType { get; } = returnType;

compiler/Program.cs

@@ -60,7 +60,7 @@ for (int i = 0; i < args.Length; i++)
     }
 }
 
-var moduleGraphBuilder = ModuleGraph.Create();
+var moduleGraphBuilder = ModuleGraph.CreateBuilder();
 var asts = new List<Ast>();
 var archivePaths = new List<string>();
 

compiler/Tokenizer.cs

@@ -3,13 +3,21 @@ using System.Text;
 
 namespace Compiler;
 
-public sealed class Tokenizer(string fileName, string contents)
+public class Tokenizer
 {
     public static List<Token>? Tokenize(string fileName, string contents, out List<Diagnostic> diagnostics)
     {
         return new Tokenizer(fileName, contents).Tokenize(out diagnostics);
     }
 
+    private Tokenizer(string fileName, string contents)
+    {
+        this.fileName = fileName;
+        this.contents = contents;
+    }
+
+    private readonly string fileName;
+    private readonly string contents;
     private int index;
     private int line = 1;
     private int column = 1;
@@ -53,7 +61,7 @@ public sealed class Tokenizer(string fileName, string contents)
             }
         }
 
-        if (diagnostics.Any(x => x.Severity == DiagnosticSeverity.Error))
+        if (diagnostics.Any(x => x.Severity == Diagnostic.DiagnosticSeverity.Error))
             return null;
 
         return tokens;
@@ -459,22 +467,22 @@ public abstract class Token(int line, int column, int length)
     public int Length { get; } = length;
 }
 
-public sealed class TokenIdent(int line, int column, int length, string ident) : Token(line, column, length)
+public class TokenIdent(int line, int column, int length, string ident) : Token(line, column, length)
 {
     public string Ident { get; } = ident;
 }
 
-public sealed class TokenIntLiteral(int line, int column, int length, BigInteger value) : Token(line, column, length)
+public class TokenIntLiteral(int line, int column, int length, BigInteger value) : Token(line, column, length)
 {
     public BigInteger Value { get; } = value;
 }
 
-public sealed class TokenStringLiteral(int line, int column, int length, string value) : Token(line, column, length)
+public class TokenStringLiteral(int line, int column, int length, string value) : Token(line, column, length)
 {
     public string Value { get; } = value;
 }
 
-public sealed class TokenBoolLiteral(int line, int column, int length, bool value) : Token(line, column, length)
+public class TokenBoolLiteral(int line, int column, int length, bool value) : Token(line, column, length)
 {
     public bool Value { get; } = value;
 }
@@ -516,7 +524,7 @@ public enum Symbol
     PipePipe,
 }
 
-public sealed class TokenSymbol(int line, int column, int length, Symbol symbol) : Token(line, column, length)
+public class TokenSymbol(int line, int column, int length, Symbol symbol) : Token(line, column, length)
 {
     public Symbol Symbol { get; } = symbol;
 }
@@ -535,7 +543,7 @@ public enum Keyword
     Export,
 }
 
-public sealed class TokenKeyword(int line, int column, int length, Keyword keyword) : Token(line, column, length)
+public class TokenKeyword(int line, int column, int length, Keyword keyword) : Token(line, column, length)
 {
     public Keyword Keyword { get; } = keyword;
 }

compiler/TypeChecker.cs

@@ -1,12 +1,24 @@
 namespace Compiler;
 
-public sealed class TypeChecker(string fileName, string moduleName, NodeDefinitionFunc function, ModuleGraph moduleGraph)
+public class TypeChecker
 {
     public static TypedNodeDefinitionFunc? CheckFunction(string fileName, string moduleName, NodeDefinitionFunc function, ModuleGraph moduleGraph, out List<Diagnostic> diagnostics)
     {
         return new TypeChecker(fileName, moduleName, function, moduleGraph).CheckFunction(out diagnostics);
     }
 
+    private TypeChecker(string fileName, string moduleName, NodeDefinitionFunc function, ModuleGraph moduleGraph)
+    {
+        this.fileName = fileName;
+        this.moduleName = moduleName;
+        this.function = function;
+        this.moduleGraph = moduleGraph;
+    }
+
+    private readonly string fileName;
+    private readonly string moduleName;
+    private readonly NodeDefinitionFunc function;
+    private readonly ModuleGraph moduleGraph;
     private readonly Scope scope = new(null);
 
     private TypedNodeDefinitionFunc? CheckFunction(out List<Diagnostic> diagnostics)
@@ -422,7 +434,7 @@ public abstract class TypedNodeDefinition(List<Token> tokens, string module) : T
     public string Module { get; } = module;
 }
 
-public sealed class TypedNodeDefinitionFunc(List<Token> tokens, string module, TokenIdent name, List<TypedNodeDefinitionFunc.Param> parameters, TypedNodeStatement body, NubType returnType) : TypedNodeDefinition(tokens, module)
+public class TypedNodeDefinitionFunc(List<Token> tokens, string module, TokenIdent name, List<TypedNodeDefinitionFunc.Param> parameters, TypedNodeStatement body, NubType returnType) : TypedNodeDefinition(tokens, module)
 {
     public TokenIdent Name { get; } = name;
     public List<Param> Parameters { get; } = parameters;
@@ -439,7 +451,7 @@ public sealed class TypedNodeDefinitionFunc(List<Token> tokens, string module, T
         return SymbolNameGen.Exported(Module, Name.Ident, GetNubType());
     }
 
-    public sealed class Param(List<Token> tokens, TokenIdent name, NubType type) : TypedNode(tokens)
+    public class Param(List<Token> tokens, TokenIdent name, NubType type) : TypedNode(tokens)
     {
         public TokenIdent Name { get; } = name;
         public NubType Type { get; } = type;
@@ -448,43 +460,43 @@ public sealed class TypedNodeDefinitionFunc(List<Token> tokens, string module, T
 
 public abstract class TypedNodeStatement(List<Token> tokens) : TypedNode(tokens);
 
-public sealed class TypedNodeStatementBlock(List<Token> tokens, List<TypedNodeStatement> statements) : TypedNodeStatement(tokens)
+public class TypedNodeStatementBlock(List<Token> tokens, List<TypedNodeStatement> statements) : TypedNodeStatement(tokens)
 {
     public List<TypedNodeStatement> Statements { get; } = statements;
 }
 
-public sealed class TypedNodeStatementFuncCall(List<Token> tokens, TypedNodeExpression target, List<TypedNodeExpression> parameters) : TypedNodeStatement(tokens)
+public class TypedNodeStatementFuncCall(List<Token> tokens, TypedNodeExpression target, List<TypedNodeExpression> parameters) : TypedNodeStatement(tokens)
 {
     public TypedNodeExpression Target { get; } = target;
     public List<TypedNodeExpression> Parameters { get; } = parameters;
 }
 
-public sealed class TypedNodeStatementReturn(List<Token> tokens, TypedNodeExpression value) : TypedNodeStatement(tokens)
+public class TypedNodeStatementReturn(List<Token> tokens, TypedNodeExpression value) : TypedNodeStatement(tokens)
 {
     public TypedNodeExpression Value { get; } = value;
 }
 
-public sealed class TypedNodeStatementVariableDeclaration(List<Token> tokens, TokenIdent name, NubType type, TypedNodeExpression value) : TypedNodeStatement(tokens)
+public class TypedNodeStatementVariableDeclaration(List<Token> tokens, TokenIdent name, NubType type, TypedNodeExpression value) : TypedNodeStatement(tokens)
 {
     public TokenIdent Name { get; } = name;
     public NubType Type { get; } = type;
     public TypedNodeExpression Value { get; } = value;
 }
 
-public sealed class TypedNodeStatementAssignment(List<Token> tokens, TypedNodeExpression target, TypedNodeExpression value) : TypedNodeStatement(tokens)
+public class TypedNodeStatementAssignment(List<Token> tokens, TypedNodeExpression target, TypedNodeExpression value) : TypedNodeStatement(tokens)
 {
     public TypedNodeExpression Target { get; } = target;
     public TypedNodeExpression Value { get; } = value;
 }
 
-public sealed class TypedNodeStatementIf(List<Token> tokens, TypedNodeExpression condition, TypedNodeStatement thenBlock, TypedNodeStatement? elseBlock) : TypedNodeStatement(tokens)
+public class TypedNodeStatementIf(List<Token> tokens, TypedNodeExpression condition, TypedNodeStatement thenBlock, TypedNodeStatement? elseBlock) : TypedNodeStatement(tokens)
 {
     public TypedNodeExpression Condition { get; } = condition;
     public TypedNodeStatement ThenBlock { get; } = thenBlock;
     public TypedNodeStatement? ElseBlock { get; } = elseBlock;
 }
 
-public sealed class TypedNodeStatementWhile(List<Token> tokens, TypedNodeExpression condition, TypedNodeStatement block) : TypedNodeStatement(tokens)
+public class TypedNodeStatementWhile(List<Token> tokens, TypedNodeExpression condition, TypedNodeStatement block) : TypedNodeStatement(tokens)
 {
     public TypedNodeExpression Condition { get; } = condition;
     public TypedNodeStatement Block { get; } = block;
@@ -495,56 +507,56 @@ public abstract class TypedNodeExpression(List<Token> tokens, NubType type) : Ty
     public NubType Type { get; } = type;
 }
 
-public sealed class TypedNodeExpressionIntLiteral(List<Token> tokens, NubType type, TokenIntLiteral value) : TypedNodeExpression(tokens, type)
+public class TypedNodeExpressionIntLiteral(List<Token> tokens, NubType type, TokenIntLiteral value) : TypedNodeExpression(tokens, type)
 {
     public TokenIntLiteral Value { get; } = value;
 }
 
-public sealed class TypedNodeExpressionStringLiteral(List<Token> tokens, NubType type, TokenStringLiteral value) : TypedNodeExpression(tokens, type)
+public class TypedNodeExpressionStringLiteral(List<Token> tokens, NubType type, TokenStringLiteral value) : TypedNodeExpression(tokens, type)
 {
     public TokenStringLiteral Value { get; } = value;
 }
 
-public sealed class TypedNodeExpressionBoolLiteral(List<Token> tokens, NubType type, TokenBoolLiteral value) : TypedNodeExpression(tokens, type)
+public class TypedNodeExpressionBoolLiteral(List<Token> tokens, NubType type, TokenBoolLiteral value) : TypedNodeExpression(tokens, type)
 {
     public TokenBoolLiteral Value { get; } = value;
 }
 
-public sealed class TypedNodeExpressionStructLiteral(List<Token> tokens, NubType type, List<TypedNodeExpressionStructLiteral.Initializer> initializers) : TypedNodeExpression(tokens, type)
+public class TypedNodeExpressionStructLiteral(List<Token> tokens, NubType type, List<TypedNodeExpressionStructLiteral.Initializer> initializers) : TypedNodeExpression(tokens, type)
 {
     public List<Initializer> Initializers { get; } = initializers;
 
-    public sealed class Initializer(List<Token> tokens, TokenIdent name, TypedNodeExpression value) : Node(tokens)
+    public class Initializer(List<Token> tokens, TokenIdent name, TypedNodeExpression value) : Node(tokens)
     {
         public TokenIdent Name { get; } = name;
         public TypedNodeExpression Value { get; } = value;
     }
 }
 
-public sealed class TypedNodeExpressionMemberAccess(List<Token> tokens, NubType type, TypedNodeExpression target, TokenIdent name) : TypedNodeExpression(tokens, type)
+public class TypedNodeExpressionMemberAccess(List<Token> tokens, NubType type, TypedNodeExpression target, TokenIdent name) : TypedNodeExpression(tokens, type)
 {
     public TypedNodeExpression Target { get; } = target;
     public TokenIdent Name { get; } = name;
 }
 
-public sealed class TypedNodeExpressionFuncCall(List<Token> tokens, NubType type, TypedNodeExpression target, List<TypedNodeExpression> parameters) : TypedNodeExpression(tokens, type)
+public class TypedNodeExpressionFuncCall(List<Token> tokens, NubType type, TypedNodeExpression target, List<TypedNodeExpression> parameters) : TypedNodeExpression(tokens, type)
 {
     public TypedNodeExpression Target { get; } = target;
     public List<TypedNodeExpression> Parameters { get; } = parameters;
 }
 
-public sealed class TypedNodeExpressionLocalIdent(List<Token> tokens, NubType type, TokenIdent value) : TypedNodeExpression(tokens, type)
+public class TypedNodeExpressionLocalIdent(List<Token> tokens, NubType type, TokenIdent value) : TypedNodeExpression(tokens, type)
 {
     public TokenIdent Value { get; } = value;
 }
 
-public sealed class TypedNodeExpressionModuleIdent(List<Token> tokens, NubType type, TokenIdent module, TokenIdent value) : TypedNodeExpression(tokens, type)
+public class TypedNodeExpressionModuleIdent(List<Token> tokens, NubType type, TokenIdent module, TokenIdent value) : TypedNodeExpression(tokens, type)
 {
     public TokenIdent Module { get; } = module;
     public TokenIdent Value { get; } = value;
 }
 
-public sealed class TypedNodeExpressionBinary(List<Token> tokens, NubType type, TypedNodeExpression left, TypedNodeExpressionBinary.Op operation, TypedNodeExpression right) : TypedNodeExpression(tokens, type)
+public class TypedNodeExpressionBinary(List<Token> tokens, NubType type, TypedNodeExpression left, TypedNodeExpressionBinary.Op operation, TypedNodeExpression right) : TypedNodeExpression(tokens, type)
 {
     public TypedNodeExpression Left { get; } = left;
     public Op Operation { get; } = operation;
@@ -577,7 +589,7 @@ public sealed class TypedNodeExpressionBinary(List<Token> tokens, NubType type,
     }
 }
 
-public sealed class TypedNodeExpressionUnary(List<Token> tokens, NubType type, TypedNodeExpression target, TypedNodeExpressionUnary.Op op) : TypedNodeExpression(tokens, type)
+public class TypedNodeExpressionUnary(List<Token> tokens, NubType type, TypedNodeExpression target, TypedNodeExpressionUnary.Op op) : TypedNodeExpression(tokens, type)
 {
     public TypedNodeExpression Target { get; } = target;
     public Op Operation { get; } = op;