more type validation

generators/wraith.lex

@@ -14,6 +14,7 @@
 "bool"                      return BOOL;
 "MemoryAddress"             return MEMORYADDRESS;
 "struct"                    return STRUCT;
+"interface"                 return INTERFACE;
 "return"                    return RETURN;
 "static"                    return STATIC;
 "Reference"                 return REFERENCE;

generators/wraith.y

@@ -27,6 +27,7 @@ extern FILE *yyin;
 %token BOOL
 %token MEMORYADDRESS
 %token STRUCT
+%token INTERFACE
 %token RETURN
 %token STATIC
 %token REFERENCE
@@ -150,6 +151,11 @@ AccessExpression        : Identifier POINT AccessExpression
                         {
                             $$ = $1;
                         }
+						| BaseType POINT AccessExpression
+						{
+							$$ = MakeAccessExpressionNode($1, $3);
+						}
+						;
 
 SystemCallExpression    : AT Identifier
                         {
@@ -355,6 +361,10 @@ GenericDeclaration      : Identifier
                         {
                             $$ = MakeGenericDeclarationNode($1, NULL);
                         }
+                        | Identifier COLON Type
+                        {
+                            $$ = MakeGenericDeclarationNode($1, $3);
+                        }
 
 GenericDeclarations     : GenericDeclaration
                         {
@@ -433,7 +443,28 @@ Declarations            : Declaration
                             $$ = AddDeclarationNode($1, $2);
                         }
 
-TopLevelDeclaration     : StructDeclaration;
+InterfaceMember         : FunctionSignature SEMICOLON
+                        {
+                            $$ = $1;
+                        }
+
+InterfaceMembers        : InterfaceMember
+                        {
+                            $$ = StartInterfaceMembersNode($1);
+                        }
+                        | InterfaceMembers InterfaceMember
+                        {
+                            $$ = AddInterfaceMemberNode($1, $2);
+                        }
+
+InterfaceDeclaration    : INTERFACE Identifier GenericDeclarationClause LEFT_BRACE InterfaceMembers RIGHT_BRACE
+                        {
+                            $$ = MakeInterfaceDeclarationNode($2, $5, $3);
+                        }
+
+TopLevelDeclaration     : StructDeclaration
+                        | InterfaceDeclaration
+                        ;
 
 TopLevelDeclarations    : TopLevelDeclaration
                         {

generic.w

@@ -14,6 +14,15 @@ struct MemoryBlock<T>
 	start: MemoryAddress;
 	capacity: uint;
 
+	static Init(capacity: uint): MemoryBlock<T>
+	{
+		return MemoryBlock<T>
+		{
+			capacity: capacity,
+			start: @malloc(capacity * @sizeof<T>())
+		};
+	}
+
 	AddressOf(index: uint): MemoryAddress
     {
         return start + (index * @sizeof<T>());
@@ -35,25 +44,40 @@ struct MemoryBlock<T>
     }
 }
 
+struct Array<T>
+{
+    memoryBlock: MemoryBlock<T>;
+
+    static Init(capacity: uint): Array<T>
+    {
+        return Array<T>
+        {
+            memoryBlock: MemoryBlock<T>.Init(capacity)
+        };
+    }
+
+    Get(index: uint): T
+    {
+        return memoryBlock.Get(index);
+    }
+
+	Set(index: uint, value: T): void
+	{
+		memoryBlock.Set(index, value);
+	}
+}
+
 struct Program {
     static Main(): int {
+        array: Array<int> = Array<int>.Init(4);
         x: int = 4;
         y: int = Foo.Func(x);
-        block: MemoryBlock<int> = MemoryBlock<int>
-        {
-            capacity: y,
-            start: @malloc(y * @sizeof<int>())
-        };
-        block.Set(0, 5);
-        block.Set(1, 3);
-        block.Set(2, 9);
-        block.Set(3, 100);
-        Console.PrintLine("%p", block.start);
-        Console.PrintLine("%i", block.Get(0));
-        Console.PrintLine("%i", block.Get(1));
-        Console.PrintLine("%i", block.Get(2));
-        Console.PrintLine("%i", block.Get(3));
-        block.Free();
+		array.Set(0, 2);
+		array.Set(1, 0);
+		array.Set(2, 5);
+		array.Set(3, 9);
+        Console.PrintLine("%i", array.Get(0));
+		Console.PrintLine("%i", array.Get(3));
         return 0;
     }
 }

interface.w

@@ -0,0 +1,30 @@
+struct Ass
+{
+    Fart(): void
+    {
+        Console.PrintLine("Poot!");
+    }
+}
+
+interface Farter
+{
+    Fart(): void;
+}
+
+struct FartDispatcher
+{
+    static Fart<T : Farter>(farter: T): void
+    {
+        farter.Fart();
+    }
+}
+
+struct Program {
+    static Main(): int {
+        ass: Ass;
+
+        FartDispatcher.Fart(ass);
+
+        return 0;
+    }
+}

src/ast.c

@@ -612,6 +612,43 @@ Node *MakeStructInitExpressionNode(Node *typeNode, Node *structInitFieldsNode)
     return node;
 }
 
+Node *MakeInterfaceDeclarationNode(
+    Node *identifierNode,
+    Node *interfaceMembersNode,
+    Node *genericDeclarationsNode)
+{
+    Node *node = (Node *)malloc(sizeof(Node));
+    node->syntaxKind = Interface;
+    node->interface.identifier = identifierNode;
+    node->interface.interfaceMembers = interfaceMembersNode;
+    node->interface.genericDeclarations = genericDeclarationsNode;
+    return node;
+}
+
+Node *StartInterfaceMembersNode(Node *interfaceMemberNode)
+{
+    Node *node = (Node *)malloc(sizeof(Node));
+    node->syntaxKind = InterfaceMembers;
+    node->interfaceMembers.members = (Node **)malloc(sizeof(Node *));
+    node->interfaceMembers.members[0] = interfaceMemberNode;
+    node->interfaceMembers.count = 1;
+    return node;
+}
+
+Node *AddInterfaceMemberNode(
+    Node *interfaceMembersNode,
+    Node *interfaceMemberNode)
+{
+    interfaceMembersNode->interfaceMembers.members = realloc(
+        interfaceMembersNode->interfaceMembers.members,
+        sizeof(Node *) * (interfaceMembersNode->interfaceMembers.count + 1));
+    interfaceMembersNode->interfaceMembers
+        .members[interfaceMembersNode->interfaceMembers.count] =
+        interfaceMemberNode;
+    interfaceMembersNode->interfaceMembers.count += 1;
+    return interfaceMembersNode;
+}
+
 static const char *PrimitiveTypeToString(PrimitiveType type)
 {
     switch (type)
@@ -1349,6 +1386,10 @@ void LinkParentPointers(Node *node, Node *prev)
     case Comment:
         return;
 
+	case ConcreteGenericTypeNode:
+		LinkParentPointers(node->concreteGenericType.genericArguments, node);
+		return;
+
     case CustomTypeNode:
         return;
 
@@ -1388,6 +1429,7 @@ void LinkParentPointers(Node *node, Node *prev)
     case FunctionCallExpression:
         LinkParentPointers(node->functionCallExpression.identifier, node);
         LinkParentPointers(node->functionCallExpression.argumentSequence, node);
+		LinkParentPointers(node->functionCallExpression.genericArguments, node);
         return;
 
     case FunctionDeclaration:
@@ -1458,6 +1500,11 @@ void LinkParentPointers(Node *node, Node *prev)
         LinkParentPointers(node->ifElseStatement.elseStatement, node);
         return;
 
+	case Interface:
+		LinkParentPointers(node->interface.genericDeclarations, node);
+		LinkParentPointers(node->interface.interfaceMembers, node);
+		return;
+
     case Number:
         return;
 
@@ -1512,6 +1559,7 @@ void LinkParentPointers(Node *node, Node *prev)
         return;
 
     case Type:
+		LinkParentPointers(node->type.typeNode, node);
         return;
 
     case UnaryExpression:

src/ast.h

@@ -39,6 +39,8 @@ typedef enum
     Identifier,
     IfStatement,
     IfElseStatement,
+    Interface,
+    InterfaceMembers,
     Number,
     PrimitiveTypeNode,
     ReferenceTypeNode,
@@ -284,6 +286,19 @@ struct Node
             Node *elseStatement;
         } ifElseStatement;
 
+        struct
+        {
+            Node *identifier;
+            Node *interfaceMembers;
+            Node *genericDeclarations;
+        } interface;
+
+        struct
+        {
+            Node **members;
+            uint32_t count;
+        } interfaceMembers;
+
         struct
         {
             uint64_t value;
@@ -445,6 +460,14 @@ Node *StartStructInitFieldsNode(Node *fieldInitNode);
 Node *AddFieldInitNode(Node *structInitFieldsNode, Node *fieldInitNode);
 Node *MakeEmptyFieldInitNode();
 Node *MakeStructInitExpressionNode(Node *typeNode, Node *structInitFieldsNode);
+Node *MakeInterfaceDeclarationNode(
+    Node *identifierNode,
+    Node *interfaceMembersNode,
+    Node *genericDeclarationsNode);
+Node *StartInterfaceMembersNode(Node *interfaceMemberNode);
+Node *AddInterfaceMemberNode(
+    Node *interfaceMembersNode,
+    Node *interfaceMemberNode);
 
 void PrintNode(Node *node, uint32_t tabCount);
 const char *SyntaxKindString(SyntaxKind syntaxKind);

src/codegen.c

@@ -111,7 +111,7 @@ struct StructTypeDeclaration
     uint32_t genericFunctionCount;
 };
 
-StructTypeDeclaration *structTypeDeclarations;
+StructTypeDeclaration **structTypeDeclarations;
 uint32_t structTypeDeclarationCount;
 
 typedef struct MonomorphizedGenericStructHashEntry
@@ -401,9 +401,9 @@ static LLVMTypeRef LookupCustomType(char *name)
 
     for (i = 0; i < structTypeDeclarationCount; i += 1)
     {
-        if (strcmp(structTypeDeclarations[i].name, name) == 0)
+        if (strcmp(structTypeDeclarations[i]->name, name) == 0)
         {
-            return structTypeDeclarations[i].structType;
+            return structTypeDeclarations[i]->structType;
         }
     }
 
@@ -420,27 +420,30 @@ static StructTypeDeclaration *AddStructDeclaration(
     uint32_t index = structTypeDeclarationCount;
     structTypeDeclarations = realloc(
         structTypeDeclarations,
-        sizeof(StructTypeDeclaration) * (structTypeDeclarationCount + 1));
-    structTypeDeclarations[index].module = module;
-    structTypeDeclarations[index].structType = wStructType;
-    structTypeDeclarations[index].structPointerType = wStructPointerType;
-    structTypeDeclarations[index].name = strdup(name);
-    structTypeDeclarations[index].fields = NULL;
-    structTypeDeclarations[index].fieldCount = 0;
-    structTypeDeclarations[index].functions = NULL;
-    structTypeDeclarations[index].functionCount = 0;
-    structTypeDeclarations[index].genericFunctions = NULL;
-    structTypeDeclarations[index].genericFunctionCount = 0;
+        sizeof(StructTypeDeclaration*) * (structTypeDeclarationCount + 1));
+	structTypeDeclarations[index] = malloc(sizeof(StructTypeDeclaration));
+    structTypeDeclarations[index]->module = module;
+    structTypeDeclarations[index]->structType = wStructType;
+    structTypeDeclarations[index]->structPointerType = wStructPointerType;
+    structTypeDeclarations[index]->name = strdup(name);
+    structTypeDeclarations[index]->fields = NULL;
+    structTypeDeclarations[index]->fieldCount = 0;
+    structTypeDeclarations[index]->functions = NULL;
+    structTypeDeclarations[index]->functionCount = 0;
+    structTypeDeclarations[index]->genericFunctions = NULL;
+    structTypeDeclarations[index]->genericFunctionCount = 0;
 
     structTypeDeclarationCount += 1;
 
-    return &structTypeDeclarations[index];
+    return structTypeDeclarations[index];
 }
 
-static StructTypeDeclaration *CompileMonomorphizedGenericStruct(
+static MonomorphizedGenericStructHashEntry *CompileMonomorphizedGenericStruct(
     GenericStructTypeDeclaration *genericStructTypeDeclaration,
     TypeTag **genericArgumentTypes,
-    uint32_t genericArgumentTypeCount)
+    uint32_t genericArgumentTypeCount,
+	MonomorphizedGenericStructHashArray *hashArray,
+	uint64_t typeHash)
 {
     uint32_t i = 0;
     uint32_t fieldCount = 0;
@@ -486,6 +489,25 @@ static StructTypeDeclaration *CompileMonomorphizedGenericStruct(
 
     free(structName);
 
+	/* add entry to the hash array here in case of recursion */
+	hashArray->elements = realloc(
+		hashArray->elements,
+		sizeof(MonomorphizedGenericStructHashEntry) *
+			(hashArray->count + 1));
+	hashArray->elements[hashArray->count].key = typeHash;
+	hashArray->elements[hashArray->count].types =
+		malloc(sizeof(TypeTag *) * genericArgumentTypeCount);
+	hashArray->elements[hashArray->count].typeCount =
+		genericArgumentTypeCount;
+	hashArray->elements[hashArray->count].structDeclaration =
+		declaration;
+	for (uint32_t j = 0; j < genericArgumentTypeCount; j += 1)
+	{
+		hashArray->elements[hashArray->count].types[j] =
+			genericArgumentTypes[j];
+	}
+	hashArray->count += 1;
+
     /* first build the structure def */
     for (i = 0; i < declarationCount; i += 1)
     {
@@ -528,7 +550,7 @@ static StructTypeDeclaration *CompileMonomorphizedGenericStruct(
 
     PopScopeFrame(scope);
 
-    return declaration;
+    return &hashArray->elements[hashArray->count - 1];;
 }
 
 static StructTypeDeclaration *LookupGenericStructType(
@@ -578,38 +600,20 @@ static StructTypeDeclaration *LookupGenericStructType(
 
                 if (match)
                 {
-                    hashEntry = &hashArray->elements[i];
+                    hashEntry = &hashArray->elements[j];
                     break;
                 }
             }
 
             if (hashEntry == NULL)
             {
-                StructTypeDeclaration *structTypeDeclaration =
+                hashEntry =
                     CompileMonomorphizedGenericStruct(
                         &genericStructTypeDeclarations[i],
                         genericTypeTags,
-                        typeTag->genericArgumentCount);
-
-                hashArray->elements = realloc(
-                    hashArray->elements,
-                    sizeof(MonomorphizedGenericStructHashEntry) *
-                        (hashArray->count + 1));
-                hashArray->elements[hashArray->count].key = typeHash;
-                hashArray->elements[hashArray->count].types =
-                    malloc(sizeof(TypeTag *) * typeTag->genericArgumentCount);
-                hashArray->elements[hashArray->count].typeCount =
-                    typeTag->genericArgumentCount;
-                hashArray->elements[hashArray->count].structDeclaration =
-                    structTypeDeclaration;
-                for (j = 0; j < typeTag->genericArgumentCount; j += 1)
-                {
-                    hashArray->elements[hashArray->count].types[j] =
-                        genericTypeTags[j];
-                }
-                hashArray->count += 1;
-
-                hashEntry = &hashArray->elements[hashArray->count - 1];
+                        typeTag->genericArgumentCount,
+						hashArray,
+						typeHash);
             }
 
             return hashEntry->structDeclaration;
@@ -688,9 +692,9 @@ static LLVMTypeRef LookupStructTypeByName(char *name)
 
     for (i = 0; i < structTypeDeclarationCount; i += 1)
     {
-        if (strcmp(structTypeDeclarations[i].name, name) == 0)
+        if (strcmp(structTypeDeclarations[i]->name, name) == 0)
         {
-            return structTypeDeclarations[i].structType;
+            return structTypeDeclarations[i]->structType;
         }
     }
 
@@ -703,9 +707,9 @@ static StructTypeDeclaration *LookupStructDeclaration(LLVMTypeRef structType)
 
     for (i = 0; i < structTypeDeclarationCount; i += 1)
     {
-        if (structTypeDeclarations[i].structType == structType)
+        if (structTypeDeclarations[i]->structType == structType)
         {
-            return &structTypeDeclarations[i];
+            return structTypeDeclarations[i];
         }
     }
 
@@ -724,18 +728,18 @@ static LLVMValueRef FindStructFieldPointer(
 
     for (i = 0; i < structTypeDeclarationCount; i += 1)
     {
-        if (structTypeDeclarations[i].structPointerType == structPointerType)
+        if (structTypeDeclarations[i]->structPointerType == structPointerType)
         {
-            for (j = 0; j < structTypeDeclarations[i].fieldCount; j += 1)
+            for (j = 0; j < structTypeDeclarations[i]->fieldCount; j += 1)
             {
-                if (strcmp(structTypeDeclarations[i].fields[j].name, name) == 0)
+                if (strcmp(structTypeDeclarations[i]->fields[j].name, name) == 0)
                 {
                     char *ptrName = strdup(name);
                     ptrName = w_strcat(ptrName, "_ptr");
                     return LLVMBuildStructGEP(
                         builder,
                         structPointer,
-                        structTypeDeclarations[i].fields[j].index,
+                        structTypeDeclarations[i]->fields[j].index,
                         ptrName);
                     free(ptrName);
                 }
@@ -1175,29 +1179,29 @@ static LLVMValueRef LookupFunctionByType(
 
     for (i = 0; i < structTypeDeclarationCount; i += 1)
     {
-        if (structTypeDeclarations[i].structType == structType)
+        if (structTypeDeclarations[i]->structType == structType)
         {
-            for (j = 0; j < structTypeDeclarations[i].functionCount; j += 1)
+            for (j = 0; j < structTypeDeclarations[i]->functionCount; j += 1)
             {
-                if (strcmp(structTypeDeclarations[i].functions[j].name, name) ==
+                if (strcmp(structTypeDeclarations[i]->functions[j].name, name) ==
                     0)
                 {
                     *pReturnType =
-                        structTypeDeclarations[i].functions[j].returnType;
-                    *pStatic = structTypeDeclarations[i].functions[j].isStatic;
-                    return structTypeDeclarations[i].functions[j].function;
+                        structTypeDeclarations[i]->functions[j].returnType;
+                    *pStatic = structTypeDeclarations[i]->functions[j].isStatic;
+                    return structTypeDeclarations[i]->functions[j].function;
                 }
             }
 
-            for (j = 0; j < structTypeDeclarations[i].genericFunctionCount;
+            for (j = 0; j < structTypeDeclarations[i]->genericFunctionCount;
                  j += 1)
             {
                 if (strcmp(
-                        structTypeDeclarations[i].genericFunctions[j].name,
+                        structTypeDeclarations[i]->genericFunctions[j].name,
                         name) == 0)
                 {
                     return LookupGenericFunction(
-                        &structTypeDeclarations[i].genericFunctions[j],
+                        &structTypeDeclarations[i]->genericFunctions[j],
                         functionCallExpression,
                         pReturnType,
                         pStatic);
@@ -1221,29 +1225,29 @@ static LLVMValueRef LookupFunctionByPointerType(
 
     for (i = 0; i < structTypeDeclarationCount; i += 1)
     {
-        if (structTypeDeclarations[i].structPointerType == structPointerType)
+        if (structTypeDeclarations[i]->structPointerType == structPointerType)
         {
-            for (j = 0; j < structTypeDeclarations[i].functionCount; j += 1)
+            for (j = 0; j < structTypeDeclarations[i]->functionCount; j += 1)
             {
-                if (strcmp(structTypeDeclarations[i].functions[j].name, name) ==
+                if (strcmp(structTypeDeclarations[i]->functions[j].name, name) ==
                     0)
                 {
                     *pReturnType =
-                        structTypeDeclarations[i].functions[j].returnType;
-                    *pStatic = structTypeDeclarations[i].functions[j].isStatic;
-                    return structTypeDeclarations[i].functions[j].function;
+                        structTypeDeclarations[i]->functions[j].returnType;
+                    *pStatic = structTypeDeclarations[i]->functions[j].isStatic;
+                    return structTypeDeclarations[i]->functions[j].function;
                 }
             }
 
-            for (j = 0; j < structTypeDeclarations[i].genericFunctionCount;
+            for (j = 0; j < structTypeDeclarations[i]->genericFunctionCount;
                  j += 1)
             {
                 if (strcmp(
-                        structTypeDeclarations[i].genericFunctions[j].name,
+                        structTypeDeclarations[i]->genericFunctions[j].name,
                         name) == 0)
                 {
                     return LookupGenericFunction(
-                        &structTypeDeclarations[i].genericFunctions[j],
+                        &structTypeDeclarations[i]->genericFunctions[j],
                         functionCallExpression,
                         pReturnType,
                         pStatic);
@@ -1370,36 +1374,62 @@ static LLVMValueRef CompileFunctionCallExpression(
     if (functionCallExpression->functionCallExpression.identifier->syntaxKind ==
         AccessExpression)
     {
-        LLVMTypeRef typeReference = LookupStructTypeByName(
-            functionCallExpression->functionCallExpression.identifier
-                ->accessExpression.accessee->identifier.name);
+		if (functionCallExpression->functionCallExpression.identifier->accessExpression.accessee->syntaxKind ==
+			ConcreteGenericTypeNode)
+		{
+			TypeTag *typeTag =
+				MakeTypeTag(
+					functionCallExpression->functionCallExpression.identifier->accessExpression.accessee
+				);
+			LLVMTypeRef typeReference = ResolveType(typeTag);
 
-        char *functionName =
-            functionCallExpression->functionCallExpression.identifier
-                ->accessExpression.accessor->identifier.name;
+			char *functionName =
+				functionCallExpression->functionCallExpression.identifier
+					->accessExpression.accessor->identifier.name;
 
-        if (typeReference != NULL)
-        {
-            function = LookupFunctionByType(
-                typeReference,
-                functionName,
-                functionCallExpression,
-                &functionReturnType,
-                &isStatic);
-        }
-        else
-        {
-            structInstance = FindVariablePointer(
-                functionCallExpression->functionCallExpression.identifier
-                    ->accessExpression.accessee->identifier.name);
+			function = LookupFunctionByType(
+				typeReference,
+				functionName,
+				functionCallExpression,
+				&functionReturnType,
+				&isStatic
+			);
 
-            function = LookupFunctionByInstance(
-                structInstance,
-                functionName,
-                functionCallExpression,
-                &functionReturnType,
-                &isStatic);
-        }
+			free(typeTag);
+		}
+		else
+		{
+			LLVMTypeRef typeReference = LookupStructTypeByName(
+				functionCallExpression->functionCallExpression.identifier
+					->accessExpression.accessee->identifier.name);
+
+			char *functionName =
+				functionCallExpression->functionCallExpression.identifier
+					->accessExpression.accessor->identifier.name;
+
+			if (typeReference != NULL)
+			{
+				function = LookupFunctionByType(
+					typeReference,
+					functionName,
+					functionCallExpression,
+					&functionReturnType,
+					&isStatic);
+			}
+			else
+			{
+				structInstance = FindVariablePointer(
+					functionCallExpression->functionCallExpression.identifier
+						->accessExpression.accessee->identifier.name);
+
+				function = LookupFunctionByInstance(
+					structInstance,
+					functionName,
+					functionCallExpression,
+					&functionReturnType,
+					&isStatic);
+			}
+		}
     }
     else if (
         functionCallExpression->functionCallExpression.identifier->syntaxKind ==
@@ -1613,6 +1643,7 @@ static LLVMValueRef CompileStructInitExpression(
     LLVMTypeRef structType = ResolveType(
         ConcretizeType(structInitExpression->structInit.type->typeTag));
 
+	/* FIXME: this can be given by struct instead of allocated */
     LLVMValueRef structPointer =
         LLVMBuildAlloca(builder, structType, "structInit");
 
@@ -1628,19 +1659,40 @@ static LLVMValueRef CompileStructInitExpression(
                 .fieldInits[i]
                 ->fieldInit.identifier->identifier.name);
 
-        LLVMBuildStore(
-            builder,
-            CompileExpression(
+		LLVMValueRef fieldExpressionResult = CompileExpression(
                 structTypeDeclaration,
                 selfParam,
                 builder,
                 structInitExpression->structInit.initFields->structInitFields
                     .fieldInits[i]
-                    ->fieldInit.expression),
-            structFieldPointer);
+                    ->fieldInit.expression);
+
+		LLVMTypeKind fieldExpressionTypeKind = LLVMGetTypeKind(LLVMTypeOf(fieldExpressionResult));
+		if (fieldExpressionTypeKind == LLVMPointerTypeKind)
+		{
+			LLVMBuildMemCpy(
+				builder,
+				structPointer,
+				LLVMGetAlignment(structPointer),
+				fieldExpressionResult,
+				LLVMGetAlignment(fieldExpressionResult),
+				LLVMSizeOf(LLVMTypeOf(fieldExpressionResult))
+			);
+		}
+		else
+		{
+			LLVMBuildStore(
+				builder,
+				fieldExpressionResult,
+				structFieldPointer);
+		}
     }
 
-    return structPointer;
+	return LLVMBuildLoad(
+		builder,
+		structPointer,
+		"struct"
+	);
 }
 
 static LLVMValueRef CompileExpression(
@@ -2334,11 +2386,17 @@ static void Compile(
                 context,
                 declarationSequenceNode->declarationSequence.sequence[i]);
         }
+        else if (
+            declarationSequenceNode->declarationSequence.sequence[i]
+                ->syntaxKind == Interface)
+        {
+            /* Interfaces don't need to compile! */
+        }
         else
         {
             fprintf(
                 stderr,
-                "top level declarations that are not structs are "
+                "top level declarations that are not structs or interfaces are "
                 "forbidden!\n");
         }
     }

src/validation.c

@@ -432,6 +432,41 @@ void ConvertCustomsToGenerics(Node *node)
 
     switch (node->syntaxKind)
     {
+	case Type:
+	{
+		Node *type = node->type.typeNode;
+		if (type->syntaxKind == CustomTypeNode)
+        {
+            char *target = type->customType.name;
+            Node *typeLookup = LookupType(node, target);
+            if (typeLookup != NULL &&
+                typeLookup->syntaxKind == GenericDeclaration)
+            {
+                node->typeTag->type = Generic;
+                free(node->declaration.type);
+                node->declaration.type =
+                    MakeGenericTypeNode(node->typeTag->value.genericType);
+            }
+        }
+		else if (type->syntaxKind == ConcreteGenericTypeNode)
+		{
+			for (int32_t i = 0; i < node->typeTag->value.concreteGenericType.genericArgumentCount; i += 1)
+			{
+				if (node->typeTag->value.concreteGenericType.genericArguments[i]->type == Custom)
+				{
+					char *target = node->typeTag->value.concreteGenericType.genericArguments[i]->value.customType;
+					Node *typeLookup = LookupType(node, target);
+					if (typeLookup != NULL &&
+						typeLookup->syntaxKind == GenericDeclaration)
+					{
+						node->typeTag->value.concreteGenericType.genericArguments[i]->type = Generic;
+					}
+				}
+			}
+		}
+		break;
+	}
+
     case Declaration:
     {
         Node *id = node->declaration.identifier;
@@ -449,6 +484,22 @@ void ConvertCustomsToGenerics(Node *node)
                     MakeGenericTypeNode(id->typeTag->value.genericType);
             }
         }
+		else if (type->syntaxKind == ConcreteGenericTypeNode)
+		{
+			for (int32_t i = 0; i < id->typeTag->value.concreteGenericType.genericArgumentCount; i += 1)
+			{
+				if (id->typeTag->value.concreteGenericType.genericArguments[i]->type == Custom)
+				{
+					char *target = id->typeTag->value.concreteGenericType.genericArguments[i]->value.customType;
+					Node *typeLookup = LookupType(node, target);
+					if (typeLookup != NULL &&
+						typeLookup->syntaxKind == GenericDeclaration)
+					{
+						id->typeTag->value.concreteGenericType.genericArguments[i]->type = Generic;
+					}
+				}
+			}
+		}
         break;
     }
 
@@ -469,9 +520,61 @@ void ConvertCustomsToGenerics(Node *node)
                     MakeGenericTypeNode(id->typeTag->value.genericType);
             }
         }
+		else if (type->syntaxKind == ConcreteGenericTypeNode)
+		{
+			for (int32_t i = 0; i < id->typeTag->value.concreteGenericType.genericArgumentCount; i += 1)
+			{
+				if (id->typeTag->value.concreteGenericType.genericArguments[i]->type == Custom)
+				{
+					char *target = id->typeTag->value.concreteGenericType.genericArguments[i]->value.customType;
+					Node *typeLookup = LookupType(node, target);
+					if (typeLookup != NULL &&
+						typeLookup->syntaxKind == GenericDeclaration)
+					{
+						id->typeTag->value.concreteGenericType.genericArguments[i]->type = Generic;
+					}
+				}
+			}
+		}
         break;
     }
 
+	case StructInit:
+	{
+        Node *type = node->structInit.type->type.typeNode;
+		TypeTag *typeTag = node->structInit.type->typeTag;
+        if (type->syntaxKind == CustomTypeNode)
+        {
+            char *target = typeTag->value.customType;
+            Node *typeLookup = LookupType(node, target);
+            if (typeLookup != NULL &&
+                typeLookup->syntaxKind == GenericDeclaration)
+            {
+                typeTag->type = Generic;
+                free(node->functionSignature.type);
+                node->functionSignature.type =
+                    MakeGenericTypeNode(typeTag->value.genericType);
+            }
+        }
+		else if (type->syntaxKind == ConcreteGenericTypeNode)
+		{
+			for (int32_t i = 0; i < typeTag->value.concreteGenericType.genericArgumentCount; i += 1)
+			{
+				if (typeTag->value.concreteGenericType.genericArguments[i]->type == Custom)
+				{
+					char *target = typeTag->value.concreteGenericType.genericArguments[i]->value.customType;
+					Node *typeLookup = LookupType(node, target);
+					if (typeLookup != NULL &&
+						typeLookup->syntaxKind == GenericDeclaration)
+					{
+						typeTag->value.concreteGenericType.genericArguments[i]->type = Generic;
+					}
+				}
+			}
+		}
+		break;
+	}
+
     case GenericArgument:
     {
         Node *typeNode = node->genericArgument.type;