Array type works with args

example/program.nub

@@ -1,23 +1,10 @@
 import c
 
-struct Test {
+global func main(args: []string) {
-    name: ^string
+    i = 0
-}
+    printf("%d\n", args.count)
-
+    while i < args.count {
-struct Test2 {
+        printf("%s\n", args[i])
-    parent: ^Test
+        i = i + 1
-}
-
-global func main(argc: i64, argv: i64) {
-    name = "Oliver"
-
-    parent = new Test {
-        name = &name
     }
-
-    test = new Test2 {
-        parent = &parent
-    }
-
-    printf("%s\n", <string>(test.parent^.name^))
 }

src/compiler/Nub.Lang/Backend/Generator.cs

@@ -74,6 +74,7 @@ public class Generator
             }
             case NubStructType:
             case NubPointerType:
+            case NubArrayType:
             {
                 return "l";
             }
@@ -120,6 +121,7 @@ public class Generator
                 return ":" + nubCustomType.Name;
             }
             case NubPointerType:
+            case NubArrayType:
             {
                 return "l";
             }
@@ -169,6 +171,7 @@ public class Generator
                 return ":" + nubCustomType.Name;
             }
             case NubPointerType:
+            case NubArrayType:
             {
                 return "l";
             }
@@ -221,6 +224,7 @@ public class Generator
                 return definition.Fields.Sum(f => QbeTypeSize(f.Type));
             }
             case NubPointerType:
+            case NubArrayType:
             {
                 return 8;
             }
@@ -474,6 +478,13 @@ public class Generator
     private void GenerateVariableAssignment(VariableAssignmentNode variableAssignment)
     {
         var result = GenerateExpression(variableAssignment.Value);
+
+        if (_variables.TryGetValue(variableAssignment.Name, out var existingVariable))
+        {
+            _builder.AppendLine($"    storel {result}, {existingVariable.Pointer}");
+        }
+        else
+        {
             var pointerLabel = GenName();
             _builder.AppendLine($"    %{pointerLabel} ={SQT(variableAssignment.Value.Type)} alloc8 {QbeTypeSize(variableAssignment.Value.Type)}");
             _builder.AppendLine($"    storel {result}, %{pointerLabel}");
@@ -484,6 +495,7 @@ public class Generator
                 Type = variableAssignment.Value.Type
             };
         }
+    }
 
     private void GenerateWhile(WhileNode whileStatement)
     {
@@ -511,6 +523,7 @@ public class Generator
         return expression switch
         {
             AddressOfNode addressOf => GenerateAddressOf(addressOf),
+            ArrayIndexNode arrayIndex => GenerateArrayIndex(arrayIndex),
             BinaryExpressionNode binaryExpression => GenerateBinaryExpression(binaryExpression),
             CastNode cast => GenerateCast(cast),
             DereferenceNode dereference => GenerateDereference(dereference),
@@ -519,11 +532,29 @@ public class Generator
             LiteralNode literal => GenerateLiteral(literal),
             StructInitializerNode structInitializer => GenerateStructInitializer(structInitializer),
             UnaryExpressionNode unaryExpression => GenerateUnaryExpression(unaryExpression),
-            StructFieldAccessorNode structMemberAccessor => GenerateStructFieldAccessor(structMemberAccessor),
+            MemberAccessNode memberAccess => GenerateMemberAccess(memberAccess),
             _ => throw new ArgumentOutOfRangeException(nameof(expression))
         };
     }
 
+    private string GenerateArrayIndex(ArrayIndexNode arrayIndex)
+    {
+        var array = GenerateExpression(arrayIndex.Expression);
+        var index = GenerateExpression(arrayIndex.Index);
+
+        var arrayBaseType = ((NubArrayType)arrayIndex.Expression.Type).BaseType;
+        
+        var firstItem = GenName();
+        _builder.AppendLine($"    %{firstItem} =l add {array}, 8");
+        var adjustedIndex = GenName();
+        _builder.AppendLine($"    %{adjustedIndex} =l mul {index}, {QbeTypeSize(arrayBaseType)}");
+        var indexLabel = GenName();
+        _builder.AppendLine($"    %{indexLabel} ={SQT(arrayIndex.Type)} add %{firstItem}, %{adjustedIndex}");
+        var outputLabel = GenName();
+        _builder.AppendLine($"    %{outputLabel} =l load{SQT(arrayBaseType)} %{indexLabel}");
+        return $"%{outputLabel}";
+    }
+
     private string GenerateDereference(DereferenceNode dereference)
     {
         var result = GenerateExpression(dereference.Expression);
@@ -1354,9 +1385,25 @@ public class Generator
         throw new NotSupportedException($"Unary operator {unaryExpression.Operator} for type {unaryExpression.Operand.Type} not supported");
     }
 
-    private string GenerateStructFieldAccessor(StructFieldAccessorNode structFieldAccessor)
+    private string GenerateMemberAccess(MemberAccessNode memberAccess)
+    {
+        var expression = GenerateExpression(memberAccess.Expression);
+
+        switch (memberAccess.Expression.Type)
+        {
+            case NubArrayType:
+            {
+                if (memberAccess.Member == "count")
+                {
+                    var outputLabel = GenName();
+                    _builder.AppendLine($"    %{outputLabel} =l loadl {expression}");
+                    return $"%{outputLabel}";
+                }
+
+                break;
+            }
+            case NubStructType structType:
             {
-        var structType = structFieldAccessor.Struct.Type;
                 var structDefinition = _definitions
                     .OfType<StructDefinitionNode>()
                     .FirstOrDefault(s => s.Name == structType.Name);
@@ -1366,12 +1413,10 @@ public class Generator
                     throw new Exception($"Struct {structType.Name} is not defined");
                 }
                 
-        var @struct = GenerateExpression(structFieldAccessor.Struct);
-
                 var fieldIndex = -1;
                 for (var i = 0; i < structDefinition.Fields.Count; i++)
                 {
-            if (structDefinition.Fields[i].Name == structFieldAccessor.Field)
+                    if (structDefinition.Fields[i].Name == memberAccess.Member)
                     {
                         fieldIndex = i;
                         break;
@@ -1380,17 +1425,21 @@ public class Generator
 
                 if (fieldIndex == -1)
                 {
-            throw new Exception($"Field {structFieldAccessor.Field} is not defined in struct {structType.Name}");
+                    throw new Exception($"Field {memberAccess.Member} is not defined in struct {structType.Name}");
                 }
 
                 var offsetLabel = GenName();
-        _builder.AppendLine($"    %{offsetLabel} =l add {@struct}, {fieldIndex * QbeTypeSize(structFieldAccessor.Type)}");
+                _builder.AppendLine($"    %{offsetLabel} =l add {expression}, {fieldIndex * QbeTypeSize(memberAccess.Type)}");
 
                 var outputLabel = GenName();
-        _builder.AppendLine($"    %{outputLabel} ={SQT(structFieldAccessor.Type)} load{SQT(structFieldAccessor.Type)} %{offsetLabel}");
+                _builder.AppendLine($"    %{outputLabel} ={SQT(memberAccess.Type)} load{SQT(memberAccess.Type)} %{offsetLabel}");
 
                 return $"%{outputLabel}";
             }
+        }
+        
+        throw new ArgumentOutOfRangeException(nameof(memberAccess.Expression.Type));
+    }
 
     private string GenerateExpressionFuncCall(FuncCallExpressionNode funcCall)
     {

src/compiler/Nub.Lang/Frontend/Parsing/ArrayIndexNode.cs

@@ -0,0 +1,7 @@
+namespace Nub.Lang.Frontend.Parsing;
+
+public class ArrayIndexNode(ExpressionNode expression, ExpressionNode index) : ExpressionNode
+{
+    public ExpressionNode Expression { get; } = expression;
+    public ExpressionNode Index { get; } = index;
+}

src/compiler/Nub.Lang/Frontend/Parsing/MemberAccessNode.cs

@@ -0,0 +1,7 @@
+namespace Nub.Lang.Frontend.Parsing;
+
+public class MemberAccessNode(ExpressionNode expression, string member) : ExpressionNode
+{
+    public ExpressionNode Expression { get; } = expression;
+    public string Member { get; } = member;
+}

src/compiler/Nub.Lang/Frontend/Parsing/Parser.cs

@@ -427,17 +427,17 @@ public class Parser
             if (TryExpectSymbol(Symbol.Period))
             {
                 var structMember = ExpectIdentifier().Value;
-                expr = new StructFieldAccessorNode(expr, structMember);
+                expr = new MemberAccessNode(expr, structMember);
                 continue;
             }
 
-            // if (TryExpectSymbol(Symbol.OpenBracket))
+            if (TryExpectSymbol(Symbol.OpenBracket))
-            // {
+            {
-            //     var index = ParseExpression();
+                var index = ParseExpression();
-            //     ExpectSymbol(Symbol.CloseBracket);
+                ExpectSymbol(Symbol.CloseBracket);
-            //     expr = new ArrayIndexNode(expr, index);
+                expr = new ArrayIndexNode(expr, index);
-            //     continue;
+                continue;
-            // }
+            }
 
             break;
         }
@@ -459,10 +459,25 @@ public class Parser
 
     private NubType ParseType()
     {
-        var pointer = TryExpectSymbol(Symbol.Caret);
+        if (TryExpectIdentifier(out var name))
-        var name = ExpectIdentifier().Value;
+        {
-        var type = NubType.Parse(name);
+            return NubType.Parse(name);
-        return pointer ? new NubPointerType(type) : type;
+        }
+        
+        if (TryExpectSymbol(Symbol.Caret))
+        {
+            var baseType = ParseType();
+            return new NubPointerType(baseType);
+        }
+
+        if (TryExpectSymbol(Symbol.OpenBracket))
+        {
+            ExpectSymbol(Symbol.CloseBracket);
+            var baseType = ParseType();
+            return new NubArrayType(baseType);
+        }
+
+        throw new Exception($"Unexpected token {Peek()} when parsing type");
     }
 
     private Token ExpectToken()
@@ -517,6 +532,19 @@ public class Parser
         return false;
     }
 
+    private bool TryExpectIdentifier([NotNullWhen(true)] out string? identifier)
+    {
+        if (Peek() is { HasValue: true, Value: IdentifierToken identifierToken })
+        {
+            identifier = identifierToken.Value;
+            Next();
+            return true;
+        }
+
+        identifier = null;
+        return false;
+    }
+
     private IdentifierToken ExpectIdentifier()
     {
         var token = ExpectToken();

src/compiler/Nub.Lang/Frontend/Parsing/StructFieldAccessorNode.cs

@@ -1,7 +0,0 @@
-namespace Nub.Lang.Frontend.Parsing;
-
-public class StructFieldAccessorNode(ExpressionNode @struct, string field) : ExpressionNode
-{
-    public ExpressionNode Struct { get; } = @struct;
-    public string Field { get; } = field;
-}

src/compiler/Nub.Lang/Frontend/Typing/TypeChecker.cs

@@ -253,6 +253,7 @@ public class TypeChecker
         var resultType = expression switch
         {
             AddressOfNode addressOf => TypeCheckAddressOf(addressOf),
+            ArrayIndexNode arrayIndex => TypeCheckArrayIndex(arrayIndex),
             LiteralNode literal => literal.LiteralType,
             IdentifierNode identifier => TypeCheckIdentifier(identifier),
             BinaryExpressionNode binaryExpr => TypeCheckBinaryExpression(binaryExpr),
@@ -261,7 +262,7 @@ public class TypeChecker
             FuncCallExpressionNode funcCallExpr => TypeCheckFuncCall(funcCallExpr.FuncCall),
             StructInitializerNode structInit => TypeCheckStructInitializer(structInit),
             UnaryExpressionNode unaryExpression => TypeCheckUnaryExpression(unaryExpression),
-            StructFieldAccessorNode fieldAccess => TypeCheckStructFieldAccess(fieldAccess),
+            MemberAccessNode memberAccess => TypeCheckMemberAccess(memberAccess),
             _ => throw new TypeCheckingException($"Unsupported expression type: {expression.GetType().Name}")
         };
 
@@ -269,6 +270,23 @@ public class TypeChecker
         return resultType;
     }
 
+    private NubType TypeCheckArrayIndex(ArrayIndexNode arrayIndex)
+    {
+        var expressionType = TypeCheckExpression(arrayIndex.Expression);
+        if (expressionType is not NubArrayType arrayType)
+        {
+            throw new TypeCheckingException($"Annot access index of non-array type {expressionType}");
+        }
+
+        var indexType = TypeCheckExpression(arrayIndex.Index);
+        if (!IsInteger(indexType))
+        {
+            throw new TypeCheckingException("Array index type must be an integer");
+        }
+
+        return arrayType.BaseType;
+    }
+
     private NubType TypeCheckIdentifier(IdentifierNode identifier)
     {
         if (!_variables.TryGetValue(identifier.Identifier, out var varType))
@@ -282,7 +300,7 @@ public class TypeChecker
     private NubType TypeCheckAddressOf(AddressOfNode addressOf)
     {
         TypeCheckExpression(addressOf.Expression);
-        if (addressOf.Expression is not (IdentifierNode or StructFieldAccessorNode))
+        if (addressOf.Expression is not (IdentifierNode or MemberAccessNode))
         {
             throw new TypeCheckingException($"Cannot take the address of {addressOf.Expression.Type}");
         }
@@ -422,28 +440,40 @@ public class TypeChecker
         }
     }
 
-    private NubType TypeCheckStructFieldAccess(StructFieldAccessorNode fieldAccess)
+    private NubType TypeCheckMemberAccess(MemberAccessNode memberAccess)
     {
-        var structType = TypeCheckExpression(fieldAccess.Struct);
+        var expressionType = TypeCheckExpression(memberAccess.Expression);
-        if (structType is not NubStructType customType)
+        switch (expressionType)
         {
-            throw new TypeCheckingException($"Cannot access field '{fieldAccess.Field}' on non-struct type '{structType}'");
+            case NubArrayType:
+            {
+                if (memberAccess.Member == "count")
+                {
+                    return NubPrimitiveType.I64;
                 }
 
-        var definition = _definitions.OfType<StructDefinitionNode>().FirstOrDefault(s => s.Name == customType.Name);
+                break;
+            }
+            case NubStructType structType:
+            {
+                var definition = _definitions.OfType<StructDefinitionNode>().FirstOrDefault(s => s.Name == structType.Name);
                 if (definition == null)
                 {
-            throw new TypeCheckingException($"Struct type '{customType.Name}' is not defined");
+                    throw new TypeCheckingException($"Struct type '{structType.Name}' is not defined");
                 }
 
-        var field = definition.Fields.FirstOrDefault(f => f.Name == fieldAccess.Field);
+                var field = definition.Fields.FirstOrDefault(f => f.Name == memberAccess.Member);
                 if (field == null)
                 {
-            throw new TypeCheckingException($"Field '{fieldAccess.Field}' does not exist in struct '{customType.Name}'");
+                    throw new TypeCheckingException($"Field '{memberAccess.Member}' does not exist in struct '{structType.Name}'");
                 }
 
                 return field.Type;
             }
+        }
+
+        throw new TypeCheckingException($"Cannot access member '{memberAccess.Member}' on type '{expressionType}'");
+    }
 
     private static bool AreTypesCompatible(NubType sourceType, NubType targetType)
     {
@@ -474,4 +504,27 @@ public class TypeChecker
                 return false;
         }
     }
+
+    private static bool IsInteger(NubType type)
+    {
+        if (type is not NubPrimitiveType primitiveType)
+        {
+            return false;
+        }
+
+        switch (primitiveType.Kind)
+        {
+            case PrimitiveTypeKind.I8:
+            case PrimitiveTypeKind.I16:
+            case PrimitiveTypeKind.I32:
+            case PrimitiveTypeKind.I64:
+            case PrimitiveTypeKind.U8:
+            case PrimitiveTypeKind.U16:
+            case PrimitiveTypeKind.U32:
+            case PrimitiveTypeKind.U64:
+                return true;
+            default:
+                return false;
+        }
+    }
 }

src/compiler/Nub.Lang/NubType.cs

@@ -41,7 +41,29 @@ public class NubPointerType(NubType baseType) : NubType("^" + baseType)
         return false;
     }
 
-    public override int GetHashCode() => BaseType.GetHashCode() * 31;
+    public override int GetHashCode()
+    {
+        return HashCode.Combine(base.GetHashCode(), BaseType);
+    }
+}
+
+public class NubArrayType(NubType baseType) : NubType("[]" + baseType)
+{
+    public NubType BaseType { get; } = baseType;
+    
+    public override bool Equals(object? obj)
+    {
+        if (obj is NubArrayType other)
+        {
+            return BaseType.Equals(other.BaseType);
+        }
+        return false;
+    }
+
+    public override int GetHashCode()
+    {
+        return HashCode.Combine(base.GetHashCode(), BaseType);
+    }
 }
 
 public class NubPrimitiveType(PrimitiveTypeKind kind) : NubType(KindToString(kind))

src/runtime/runtime.asm

@@ -3,11 +3,9 @@ extern main
 
 section .text
 _start:
-    ; Extract argc and argv from the stack
+    ; The args already match our array structure, so we pass the result directly
-    mov rdi, [rsp]        ; rdi = argc
+    mov rdi, rsp
-    lea rsi, [rsp + 8]    ; rsi = argv (pointer to array of strings)
 
-    ; Call main(argc, argv)
     call main             ; main returns int in rax
 
     ; Exit with main's return value
@@ -34,3 +32,4 @@ nub_strcmp:
 .equal:
     mov rax, 1
     ret
+