compiler/Compiler/Generator.cs

@@ -35,6 +35,23 @@ public sealed class Generator(List<NodeDefinition> nodes)
 
         writer.WriteLine();
 
+        foreach (var node in nodes.OfType<NodeDefinitionStruct>())
+        {
+            writer.WriteLine($"struct {node.Name.Ident}");
+            writer.WriteLine("{");
+            using (writer.Indent())
+            {
+                foreach (var field in node.Fields)
+                {
+                    writer.WriteLine($"{CType(field.Type, field.Name.Ident)};");
+                }
+            }
+
+            writer.WriteLine("};");
+        }
+
+        writer.WriteLine();
+
         foreach (var node in nodes.OfType<NodeDefinitionFunc>())
         {
             var parameters = node.Parameters.Select(x => CType(x.Type, x.Name.Ident));
@@ -171,6 +188,8 @@ public sealed class Generator(List<NodeDefinition> nodes)
             NodeExpressionBoolLiteral expression => expression.Value.Value ? "true" : "false",
             NodeExpressionIntLiteral expression => expression.Value.Value.ToString(),
             NodeExpressionStringLiteral expression => $"(struct string){{ \"{expression.Value.Value}\", {expression.Value.Value.Length} }}",
+            NodeExpressionStructLiteral expression => EmitStructLiteral(expression),
+            NodeExpressionMemberAccess expression => EmitExpressionMemberAccess(expression),
             NodeExpressionIdent expression => expression.Value.Ident,
             _ => throw new ArgumentOutOfRangeException(nameof(node), node, null)
         };
@@ -208,7 +227,7 @@ public sealed class Generator(List<NodeDefinition> nodes)
         {
             NodeTypeVoid => "void" + (varName != null ? $" {varName}" : ""),
             NodeTypeBool => "bool" + (varName != null ? $" {varName}" : ""),
-            NodeTypeCustom type => $"struct {type}" + (varName != null ? $" {varName}" : ""),
+            NodeTypeCustom type => $"struct {type.Name.Ident}" + (varName != null ? $" {varName}" : ""),
             NodeTypeSInt type => $"int{type.Width}_t" + (varName != null ? $" {varName}" : ""),
             NodeTypeUInt type => $"uint{type.Width}_t" + (varName != null ? $" {varName}" : ""),
             NodeTypePointer type => CType(type.To) + (varName != null ? $" *{varName}" : "*"),
@@ -217,6 +236,27 @@ public sealed class Generator(List<NodeDefinition> nodes)
             _ => throw new ArgumentOutOfRangeException(nameof(node), node, null)
         };
     }
+
+    private string EmitStructLiteral(NodeExpressionStructLiteral expression)
+    {
+        var initializerValues = new Dictionary<string, string>();
+
+        foreach (var initializer in expression.Initializers)
+        {
+            var values = EmitExpression(initializer.Value);
+            initializerValues[initializer.Name.Ident] = values;
+        }
+
+        var initializerStrings = initializerValues.Select(x => $".{x.Key} = {x.Value}");
+
+        return $"(struct {expression.Name.Ident}){{ {string.Join(", ", initializerStrings)} }}";
+    }
+
+    private string EmitExpressionMemberAccess(NodeExpressionMemberAccess expression)
+    {
+        var target = EmitExpression(expression.Target);
+        return $"{target}.{expression.Name.Ident}";
+    }
 }
 
 internal class IndentedTextWriter

compiler/Compiler/Parser.cs

@@ -48,6 +48,24 @@ public sealed class Parser(List<Token> tokens)
             return new NodeDefinitionFunc(TokensFrom(startIndex), name, parameters, body, returnType);
         }
 
+        if (TryExpectKeyword(Keyword.Struct))
+        {
+            var name = ExpectIdent();
+            var fields = new List<NodeDefinitionStruct.Field>();
+
+            ExpectSymbol(Symbol.OpenCurly);
+            while (!TryExpectSymbol(Symbol.CloseCurly))
+            {
+                var fieldStartIndex = index;
+                var fieldName = ExpectIdent();
+                ExpectSymbol(Symbol.Colon);
+                var fieldType = ParseType();
+                fields.Add(new NodeDefinitionStruct.Field(TokensFrom(fieldStartIndex), fieldName, fieldType));
+            }
+
+            return new NodeDefinitionStruct(TokensFrom(startIndex), name, fields);
+        }
+
         throw new Exception("Not a valid definition");
     }
 
@@ -172,36 +190,61 @@ public sealed class Parser(List<Token> tokens)
     {
         var startIndex = index;
 
+        NodeExpression expr;
+
         if (TryExpectSymbol(Symbol.OpenParen))
         {
             var value = ParseExpression();
             ExpectSymbol(Symbol.CloseParen);
-            return value;
+            expr = value;
         }
-
+        else if (TryExpectIntLiteral(out var intLiteral))
-        if (TryExpectIntLiteral(out var intLiteral))
         {
-            return new NodeExpressionIntLiteral(TokensFrom(startIndex), intLiteral);
+            expr = new NodeExpressionIntLiteral(TokensFrom(startIndex), intLiteral);
         }
-
+        else if (TryExpectStringLiteral(out var stringLiteral))
-        if (TryExpectStringLiteral(out var stringLiteral))
         {
-            return new NodeExpressionStringLiteral(TokensFrom(startIndex), stringLiteral);
+            expr = new NodeExpressionStringLiteral(TokensFrom(startIndex), stringLiteral);
         }
-
+        else if (TryExpectBoolLiteral(out var boolLiteral))
-        if (TryExpectBoolLiteral(out var boolLiteral))
         {
-            return new NodeExpressionBoolLiteral(TokensFrom(startIndex), boolLiteral);
+            expr = new NodeExpressionBoolLiteral(TokensFrom(startIndex), boolLiteral);
         }
-
+        else if (TryExpectIdent(out var ident))
-        if (TryExpectIdent(out var ident))
         {
-            return new NodeExpressionIdent(TokensFrom(startIndex), ident);
+            expr = new NodeExpressionIdent(TokensFrom(startIndex), ident);
+        }
+        else if (TryExpectKeyword(Keyword.Struct))
+        {
+            var name = ExpectIdent();
+            var initializers = new List<NodeExpressionStructLiteral.Initializer>();
+
+            ExpectSymbol(Symbol.OpenCurly);
+            while (!TryExpectSymbol(Symbol.CloseCurly))
+            {
+                var initializerStartIndex = startIndex;
+                var fieldName = ExpectIdent();
+                ExpectSymbol(Symbol.Equal);
+                var fieldValue = ParseExpression();
+                initializers.Add(new NodeExpressionStructLiteral.Initializer(TokensFrom(initializerStartIndex), fieldName, fieldValue));
             }
 
+            expr = new NodeExpressionStructLiteral(TokensFrom(startIndex), name, initializers);
+        }
+        else
+        {
             throw new Exception("Not a valid expression leaf");
         }
 
+        if (TryExpectSymbol(Symbol.Period))
+        {
+            var name = ExpectIdent();
+            expr = new NodeExpressionMemberAccess(TokensFrom(startIndex), expr, name);
+        }
+
+        return expr;
+    }
+
     private NodeType ParseType()
     {
         var startIndex = index;
@@ -462,6 +505,18 @@ public sealed class NodeDefinitionFunc(List<Token> tokens, TokenIdent name, List
     }
 }
 
+public sealed class NodeDefinitionStruct(List<Token> tokens, TokenIdent name, List<NodeDefinitionStruct.Field> fields) : NodeDefinition(tokens)
+{
+    public readonly TokenIdent Name = name;
+    public readonly List<Field> Fields = fields;
+
+    public sealed class Field(List<Token> tokens, TokenIdent name, NodeType type) : Node(tokens)
+    {
+        public readonly TokenIdent Name = name;
+        public readonly NodeType Type = type;
+    }
+}
+
 public abstract class NodeStatement(List<Token> tokens) : Node(tokens);
 
 public sealed class NodeStatementBlock(List<Token> tokens, List<NodeStatement> statements) : NodeStatement(tokens)
@@ -475,32 +530,32 @@ public sealed class NodeStatementFuncCall(List<Token> tokens, NodeExpression tar
     public readonly List<NodeExpression> Parameters = parameters;
 }
 
-public class NodeStatementReturn(List<Token> tokens, NodeExpression value) : NodeStatement(tokens)
+public sealed class NodeStatementReturn(List<Token> tokens, NodeExpression value) : NodeStatement(tokens)
 {
     public readonly NodeExpression Value = value;
 }
 
-public class NodeStatementVariableDeclaration(List<Token> tokens, TokenIdent name, NodeType type, NodeExpression value) : NodeStatement(tokens)
+public sealed class NodeStatementVariableDeclaration(List<Token> tokens, TokenIdent name, NodeType type, NodeExpression value) : NodeStatement(tokens)
 {
     public readonly TokenIdent Name = name;
     public readonly NodeType Type = type;
     public readonly NodeExpression Value = value;
 }
 
-public class NodeStatementAssignment(List<Token> tokens, NodeExpression target, NodeExpression value) : NodeStatement(tokens)
+public sealed class NodeStatementAssignment(List<Token> tokens, NodeExpression target, NodeExpression value) : NodeStatement(tokens)
 {
     public readonly NodeExpression Target = target;
     public readonly NodeExpression Value = value;
 }
 
-public class NodeStatementIf(List<Token> tokens, NodeExpression condition, NodeStatement thenBlock, NodeStatement? elseBlock) : NodeStatement(tokens)
+public sealed class NodeStatementIf(List<Token> tokens, NodeExpression condition, NodeStatement thenBlock, NodeStatement? elseBlock) : NodeStatement(tokens)
 {
     public readonly NodeExpression Condition = condition;
     public readonly NodeStatement ThenBlock = thenBlock;
     public readonly NodeStatement? ElseBlock = elseBlock;
 }
 
-public class NodeStatementWhile(List<Token> tokens, NodeExpression condition, NodeStatement block) : NodeStatement(tokens)
+public sealed class NodeStatementWhile(List<Token> tokens, NodeExpression condition, NodeStatement block) : NodeStatement(tokens)
 {
     public readonly NodeExpression Condition = condition;
     public readonly NodeStatement Block = block;
@@ -523,16 +578,34 @@ public sealed class NodeExpressionBoolLiteral(List<Token> tokens, TokenBoolLiter
     public readonly TokenBoolLiteral Value = value;
 }
 
+public sealed class NodeExpressionStructLiteral(List<Token> tokens, TokenIdent name, List<NodeExpressionStructLiteral.Initializer> initializers) : NodeExpression(tokens)
+{
+    public readonly TokenIdent Name = name;
+    public readonly List<Initializer> Initializers = initializers;
+
+    public sealed class Initializer(List<Token> tokens, TokenIdent name, NodeExpression value) : Node(tokens)
+    {
+        public readonly TokenIdent Name = name;
+        public readonly NodeExpression Value = value;
+    }
+}
+
+public sealed class NodeExpressionMemberAccess(List<Token> tokens, NodeExpression target, TokenIdent name) : NodeExpression(tokens)
+{
+    public readonly NodeExpression Target = target;
+    public readonly TokenIdent Name = name;
+}
+
 public sealed class NodeExpressionIdent(List<Token> tokens, TokenIdent value) : NodeExpression(tokens)
 {
     public readonly TokenIdent Value = value;
 }
 
-public class NodeExpressionBinary(List<Token> tokens, NodeExpression left, NodeExpressionBinary.Op operation, NodeExpression right) : NodeExpression(tokens)
+public sealed class NodeExpressionBinary(List<Token> tokens, NodeExpression left, NodeExpressionBinary.Op operation, NodeExpression right) : NodeExpression(tokens)
 {
-    public NodeExpression Left { get; } = left;
+    public readonly NodeExpression Left = left;
     public readonly Op Operation = operation;
-    public NodeExpression Right { get; } = right;
+    public readonly NodeExpression Right = right;
 
 
     public enum Op

compiler/Compiler/Program.cs

@@ -1,6 +1,11 @@
 using Compiler;
 
 const string contents = """
+                        struct person {
+                            age: i32
+                            name: string
+                        }
+
                         func main(): i32 {
                             let x: i32 = 23
                             x = 24
@@ -20,7 +25,9 @@ const string contents = """
                                 x = i
                             }
                             
-                            do_something("test")
+                            let me: person = struct person { age = 21 name = "Oliver" }
+                            
+                            do_something(me.name)
                             return x
                         }
 

compiler/Compiler/Tokenizer.cs

@@ -165,6 +165,11 @@ public sealed class Tokenizer(string contents)
                 Consume();
                 return new TokenSymbol(line, startColumn, column - startColumn, Symbol.Comma);
             }
+            case '.':
+            {
+                Consume();
+                return new TokenSymbol(line, startColumn, column - startColumn, Symbol.Period);
+            }
             case ':':
             {
                 Consume();
@@ -322,6 +327,7 @@ public sealed class Tokenizer(string contents)
                     return value switch
                     {
                         "func" => new TokenKeyword(line, startColumn, column - startColumn, Keyword.Func),
+                        "struct" => new TokenKeyword(line, startColumn, column - startColumn, Keyword.Struct),
                         "let" => new TokenKeyword(line, startColumn, column - startColumn, Keyword.Let),
                         "if" => new TokenKeyword(line, startColumn, column - startColumn, Keyword.If),
                         "else" => new TokenKeyword(line, startColumn, column - startColumn, Keyword.Else),
@@ -415,6 +421,7 @@ public enum Symbol
     OpenParen,
     CloseParen,
     Comma,
+    Period,
     Colon,
     Caret,
     Bang,
@@ -451,6 +458,7 @@ public sealed class TokenSymbol(int line, int column, int length, Symbol symbol)
 public enum Keyword
 {
     Func,
+    Struct,
     Let,
     If,
     Else,