txSlot* fxNewNumberInstance(txMachine* the)
{
txSlot* anInstance;
txSlot* aProperty;
anInstance = fxNewSlot(the);
anInstance->next = C_NULL;
anInstance->flag = XS_VALUE_FLAG;
anInstance->kind = XS_INSTANCE_KIND;
anInstance->value.instance.garbage = C_NULL;
anInstance->value.instance.prototype = C_NULL;
if (the->stack->kind == XS_ALIAS_KIND)
anInstance->ID = the->stack->value.alias;
else
anInstance->value.instance.prototype = the->stack->value.reference;
the->stack->value.reference = anInstance;
the->stack->kind = XS_REFERENCE_KIND;
aProperty = anInstance->next = fxNewSlot(the);
aProperty->next = C_NULL;
aProperty->ID = XS_NO_ID;
aProperty->flag = XS_NO_FLAG;
aProperty->kind = XS_NUMBER_KIND;
aProperty->value.number = 0;
return anInstance;
}
txSlot* fxNewHostObject(txMachine* the, txDestructor theDestructor)
{
txSlot* anInstance;
txSlot* aProperty;
mxPushUndefined();
anInstance = fxNewSlot(the);
anInstance->flag = XS_VALUE_FLAG;
anInstance->kind = XS_INSTANCE_KIND;
anInstance->value.instance.garbage = C_NULL;
anInstance->value.instance.prototype = mxObjectPrototype.value.reference;
the->stack->value.reference = anInstance;
the->stack->kind = XS_REFERENCE_KIND;
aProperty = anInstance->next = fxNewSlot(the);
aProperty->ID = XS_NO_ID;
aProperty->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
aProperty->kind = XS_HOST_KIND;
aProperty->value.host.data = C_NULL;
aProperty->value.host.variant.destructor = theDestructor;
if (the->frame && (mxFunction->kind == XS_REFERENCE_KIND)) {
txSlot* slot = mxFunctionInstanceModule(mxFunction->value.reference);
aProperty = aProperty->next = fxNewSlot(the);
aProperty->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
aProperty->kind = slot->kind;
aProperty->value = slot->value;
}
return anInstance;
}
txSlot* fxNewBooleanInstance(txMachine* the)
{
txSlot* anInstance;
txSlot* aProperty;
anInstance = fxNewSlot(the);
anInstance->next = C_NULL;
anInstance->flag = XS_VALUE_FLAG;
anInstance->kind = XS_INSTANCE_KIND;
anInstance->value.instance.garbage = C_NULL;
anInstance->value.instance.prototype = C_NULL;
if (the->stack->kind == XS_ALIAS_KIND)
anInstance->ID = the->stack->value.alias;
else
anInstance->value.instance.prototype = the->stack->value.reference;
the->stack->value.reference = anInstance;
the->stack->kind = XS_REFERENCE_KIND;
aProperty = anInstance->next = fxNewSlot(the);
aProperty->next = C_NULL;
aProperty->ID = XS_NO_ID;
aProperty->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
aProperty->kind = XS_BOOLEAN_KIND;
aProperty->value.boolean = 0;
return anInstance;
}
void fxNewProgramInstance(txMachine* the)
{
txSlot* anInstance;
txSlot* aProperty;
fxNewInstance(the);
anInstance = the->stack->value.reference;
/* CODE */
aProperty = anInstance->next = fxNewSlot(the);
*aProperty = *(the->stack + 1);
aProperty->ID = XS_NO_ID;
aProperty->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
/* CLOSURE */
aProperty = aProperty->next = fxNewSlot(the);
aProperty->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
aProperty->kind = XS_NULL_KIND;
/* PROTOTYPE */
aProperty = aProperty->next = fxNewSlot(the);
aProperty->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
#ifdef mxProfile
/* PROFILE */
aProperty = aProperty->next = fxNewSlot(the);
aProperty->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
aProperty->kind = XS_INTEGER_KIND;
aProperty->value.integer = the->profileID;
the->profileID++;
#endif
*(the->stack + 1) = *(the->stack);
the->stack++;
}
txSlot* fxNewStringInstance(txMachine* the)
{
txSlot* anInstance;
txSlot* aProperty;
anInstance = fxNewSlot(the);
anInstance->next = C_NULL;
anInstance->flag = XS_VALUE_FLAG;
anInstance->kind = XS_INSTANCE_KIND;
anInstance->value.instance.garbage = C_NULL;
anInstance->value.instance.prototype = C_NULL;
if (the->stack->kind == XS_ALIAS_KIND)
anInstance->ID = the->stack->value.alias;
else
anInstance->value.instance.prototype = the->stack->value.reference;
the->stack->value.reference = anInstance;
the->stack->kind = XS_REFERENCE_KIND;
aProperty = anInstance->next = fxNewSlot(the);
aProperty->next = C_NULL;
aProperty->ID = XS_NO_ID;
aProperty->flag = XS_NO_FLAG;
aProperty->kind = mxEmptyString.kind;
aProperty->value.string = mxEmptyString.value.string;
aProperty = aProperty->next = fxNewSlot(the);
aProperty->next = C_NULL;
aProperty->ID = the->lengthID;
aProperty->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
aProperty->kind = XS_INTEGER_KIND;
aProperty->value.integer = 0;
return anInstance;
}
void fxBuildKeys(txMachine* the)
{
txArchive* archive = the->archive;
if (archive && archive->keys)
(*archive->keys)(the);
else {
#ifdef mxParse
txSlot* code = &mxIDs;
txID c, i;
if (archive) {
c = archive->symbolCount;
code->value.code = (txByte *)fxNewChunk(the, c * sizeof(txID));
code->kind = XS_CODE_KIND;
for (i = 0; i < XS_SYMBOL_ID_COUNT; i++) {
txString string = archive->symbols[i];
txID id = the->keyIndex;
txSlot* description = fxNewSlot(the);
description->flag = XS_DONT_ENUM_FLAG;
fxCopyStringC(the, description, string);
the->keyArray[id] = description;
the->keyIndex++;
mxID(i) = 0x8000 | id;
}
for (; i < c; i++) {
txString string = archive->symbols[i];
mxID(i) = fxNewNameX(the, string)->ID;
}
}
else {
code->value.code = (txByte *)fxNewChunk(the, XS_ID_COUNT * sizeof(txID));
code->kind = XS_CODE_KIND;
for (i = 0; i < XS_SYMBOL_ID_COUNT; i++) {
txID id = the->keyIndex;
txSlot* description = fxNewSlot(the);
description->flag = XS_DONT_ENUM_FLAG;
fxCopyStringC(the, description, gxIDStrings[i]);
the->keyArray[id] = description;
the->keyIndex++;
mxID(i) = 0x8000 | id;
}
for (; i < XS_ID_COUNT; i++) {
mxID(i) = fxID(the, gxIDStrings[i]);
}
}
#else
fxCheck(the, __FILE__, __LINE__);
#endif
}
}
void fxParseJSONArray(txScriptParser* theParser)
{
txMachine* the = theParser->the;
txSlot* anArray;
txIndex aLength;
txSlot* anItem;
fxGetNextJSONToken(theParser);
*(--the->stack) = mxArrayPrototype;
anArray = fxNewArrayInstance(the);
aLength = 0;
anItem = anArray->next;
for (;;) {
if (theParser->token == XS_TOKEN_RIGHT_BRACKET)
break;
fxParseJSONValue(theParser);
aLength++;
anItem->next = fxNewSlot(the);
anItem = anItem->next;
anItem->kind = the->stack->kind;
anItem->value = the->stack->value;
the->stack++;
if (theParser->token != XS_TOKEN_COMMA)
break;
fxGetNextJSONToken(theParser);
}
anArray->next->value.array.length = aLength;
fxCacheArray(the, anArray);
if (theParser->token != XS_TOKEN_RIGHT_BRACKET)
fxReportParserError(theParser, "missing ]");
fxGetNextJSONToken(theParser);
}
void fxThrowMessage(txMachine* the, txString path, txInteger line, txError error, txString format, ...)
{
char message[128] = "";
txInteger length = 0;
va_list arguments;
txSlot* slot;
fxBufferFrameName(the, message, sizeof(message), the->frame, ": ");
length = c_strlen(message);
va_start(arguments, format);
vsnprintf(message + length, sizeof(message) - length, format, arguments);
va_end(arguments);
if ((error <= XS_NO_ERROR) || (XS_ERROR_COUNT <= error))
error = XS_UNKNOWN_ERROR;
slot = fxNewSlot(the);
slot->kind = XS_INSTANCE_KIND;
slot->value.instance.garbage = C_NULL;
slot->value.instance.prototype = mxErrorPrototypes(error).value.reference;
mxException.kind = XS_REFERENCE_KIND;
mxException.value.reference = slot;
slot = fxNextStringProperty(the, slot, message, mxID(_message), XS_DONT_ENUM_FLAG);
#ifdef mxDebug
fxDebugThrow(the, path, line, message);
#endif
fxJump(the);
}
txSlot* fxNextHostAccessorProperty(txMachine* the, txSlot* property, txCallback get, txCallback set, txID id, txFlag flag)
{
txSlot *getter = NULL, *setter = NULL, *home = the->stack, *slot;
if (get) {
getter = fxNewHostFunction(the, get, 0, id);
slot = mxFunctionInstanceHome(getter);
slot->kind = home->kind;
slot->value = home->value;
}
if (set) {
setter = fxNewHostFunction(the, set, 1, id);
slot = mxFunctionInstanceHome(setter);
slot->kind = home->kind;
slot->value = home->value;
}
property = property->next = fxNewSlot(the);
property->flag = flag;
property->ID = id;
property->kind = XS_ACCESSOR_KIND;
property->value.accessor.getter = getter;
property->value.accessor.setter = setter;
if (set)
the->stack++;
if (get)
the->stack++;
return property;
}
void fxDefaultFunctionPrototype(txMachine* the, txSlot* function, txSlot* prototype)
{
txSlot* instance;
txSlot* property;
instance = fxNewSlot(the);
instance->kind = XS_INSTANCE_KIND;
instance->value.instance.garbage = C_NULL;
instance->value.instance.prototype = mxObjectPrototype.value.reference;
prototype->kind = XS_REFERENCE_KIND;
prototype->value.reference = instance;
property = instance->next = fxNewSlot(the);
property->flag = XS_DONT_ENUM_FLAG;
property->ID = mxID(_constructor);
property->kind = XS_REFERENCE_KIND;
property->value.reference = function;
}
void fxParseJSONArray(txMachine* the, txJSONParser* theParser)
{
txSlot* anArray;
txIndex aLength;
txSlot* anItem;
fxGetNextJSONToken(the, theParser);
mxPush(mxArrayPrototype);
anArray = fxNewArrayInstance(the);
aLength = 0;
anItem = fxLastProperty(the, anArray);
for (;;) {
if (theParser->token == XS_JSON_TOKEN_RIGHT_BRACKET)
break;
fxParseJSONValue(the, theParser);
aLength++;
anItem->next = fxNewSlot(the);
anItem = anItem->next;
anItem->kind = the->stack->kind;
anItem->value = the->stack->value;
the->stack++;
if (theParser->token != XS_JSON_TOKEN_COMMA)
break;
fxGetNextJSONToken(the, theParser);
}
anArray->next->value.array.length = aLength;
fxCacheArray(the, anArray);
if (theParser->token != XS_JSON_TOKEN_RIGHT_BRACKET)
mxSyntaxError("missing ]");
fxGetNextJSONToken(the, theParser);
}
txSlot* fxCoerceToArray(txMachine* the, txSlot* slot)
{
txSlot* instance = fxToInstance(the, slot);
txSlot** address = &(instance->next);
txSlot* array = C_NULL;
txSlot* property;
while ((property = *address)) {
if (property->ID == XS_NO_ID) {
if ((property->kind == XS_ARRAY_KIND) || (property->kind == XS_PARAMETERS_KIND)) {
array = property;
break;
}
}
else
break;
address = &(property->next);
}
if (!array) {
array = *address = fxNewSlot(the);
array->next = property;
array->kind = XS_ARRAY_KIND;
array->value.array.address = C_NULL;
array->value.array.length = 0;
}
return array;
}
txSlot* fxNextNullProperty(txMachine* the, txSlot* property, txID id, txFlag flag)
{
property = property->next = fxNewSlot(the);
property->flag = flag;
property->ID = id;
property->kind = XS_NULL_KIND;
return property;
}
txSlot* fxNextUndefinedProperty(txMachine* the, txSlot* property, txID id, txFlag flag)
{
property = property->next = fxNewSlot(the);
property->flag = flag;
property->ID = id;
property->kind = XS_UNDEFINED_KIND;
return property;
}
txSlot* fxNextStringProperty(txMachine* the, txSlot* property, txString string, txID id, txFlag flag)
{
property = property->next = fxNewSlot(the);
property->flag = flag;
property->ID = id;
fxCopyStringC(the, property, string);
return property;
}
txSlot* fxNewInstance(txMachine* the)
{
txSlot* instance = fxNewSlot(the);
instance->kind = XS_INSTANCE_KIND;
instance->value.instance.garbage = C_NULL;
instance->value.instance.prototype = C_NULL;
mxPushReference(instance);
return instance;
}
txSlot* fxNextTypeDispatchProperty(txMachine* the, txSlot* property, txTypeDispatch* dispatch, txID id, txFlag flag)
{
property = property->next = fxNewSlot(the);
property->flag = flag;
property->ID = id;
property->kind = XS_TYPED_ARRAY_KIND;
property->value.typedArray = dispatch;
return property;
}
txSlot* fxNextIntegerProperty(txMachine* the, txSlot* property, txInteger integer, txID id, txFlag flag)
{
property = property->next = fxNewSlot(the);
property->flag = flag;
property->ID = id;
property->kind = XS_INTEGER_KIND;
property->value.integer = integer;
return property;
}
txSlot* fxNextBooleanProperty(txMachine* the, txSlot* property, txBoolean boolean, txID id, txFlag flag)
{
property = property->next = fxNewSlot(the);
property->flag = flag;
property->ID = id;
property->kind = XS_BOOLEAN_KIND;
property->value.boolean = boolean;
return property;
}
txSlot* fxNextSymbolProperty(txMachine* the, txSlot* property, txID symbol, txID id, txFlag flag)
{
property = property->next = fxNewSlot(the);
property->flag = flag;
property->ID = id;
property->kind = XS_SYMBOL_KIND;
property->value.ID = symbol;
return property;
}
txSlot* fxNextNumberProperty(txMachine* the, txSlot* property, txNumber number, txID id, txFlag flag)
{
property = property->next = fxNewSlot(the);
property->flag = flag;
property->ID = id;
property->kind = XS_NUMBER_KIND;
property->value.number = number;
return property;
}
txSlot* fxNextSlotProperty(txMachine* the, txSlot* property, txSlot* slot, txID id, txFlag flag)
{
property = property->next = fxNewSlot(the);
property->flag = flag;
property->ID = id;
property->kind = slot->kind;
property->value = slot->value;
return property;
}
void fxArrayCacheItem(txMachine* the, txSlot* reference, txSlot* item)
{
txSlot* array = reference->value.reference->next;
txSlot* slot = fxNewSlot(the);
slot->next = array->next;
slot->kind = item->kind;
slot->value = item->value;
array->next = slot;
array->value.array.length++;
}
void fx_Function_bind(txMachine* the)
{
txSlot* aFunction;
txSlot* aProperty;
txSlot* anArray;
txSlot* anItem;
txSize aCount, anIndex;
aFunction = fxGetInstance(the, mxThis);
if (!mxIsFunction(aFunction))
mxDebug0(the, XS_TYPE_ERROR, "this is no Function");
if (mxArgc < 1)
mxDebug0(the, XS_SYNTAX_ERROR, "Function.prototype.bind: no this parameter");
aProperty = aFunction->next;
if (aProperty->kind == XS_CODE_KIND)
aCount = *(aProperty->value.code + 4);
else
aCount = aProperty->value.callback.length;
aCount -= mxArgc - 1;
if (aCount < 0)
aCount = 0;
mxPush(mxFunctionPrototype);
aFunction = fxNewFunctionInstance(the);
*mxResult = *(the->stack++);
aProperty = aFunction->next;
aProperty->kind = XS_CALLBACK_KIND;
aProperty->value.callback.address = fx_Function_bound;
aProperty->value.callback.length = aCount;
aProperty = fxSetProperty(the, aFunction, fxID(the, "boundFunction"), C_NULL);
aProperty->kind = mxThis->kind;
aProperty->value = mxThis->value;
aProperty = fxSetProperty(the, aFunction, fxID(the, "boundThis"), C_NULL);
aProperty->kind = mxArgv(0)->kind;
aProperty->value = mxArgv(0)->value;
aProperty = fxSetProperty(the, aFunction, fxID(the, "boundArguments"), C_NULL);
mxPush(mxArrayPrototype);
anArray = fxNewArrayInstance(the);
aProperty->kind = the->stack->kind;
aProperty->value = the->stack->value;
the->stack++;
anItem = anArray->next;
for (anIndex = 1; anIndex < mxArgc; anIndex++) {
anItem->next = fxNewSlot(the);
anItem = anItem->next;
anItem->kind = mxArgv(anIndex)->kind;
anItem->value = mxArgv(anIndex)->value;
}
anArray->next->value.array.length = mxArgc - 1;
fxCacheArray(the, anArray);
}
txSlot* fxNewArrayInstance(txMachine* the)
{
txSlot* instance;
txSlot* property;
instance = fxNewObjectInstance(the);
instance->flag |= XS_VALUE_FLAG;
property = instance->next = fxNewSlot(the);
property->kind = XS_ARRAY_KIND;
property->value.array.length = 0;
property->value.array.address = C_NULL;
return instance;
}
txSlot* fxNewGlobalInstance(txMachine* the)
{
txSlot* instance;
txSlot* property;
instance = fxNewInstance(the);
instance->flag |= XS_VALUE_FLAG;
property = instance->next = fxNewSlot(the);
property->value.table.address = (txSlot**)fxNewChunk(the, the->keyCount * sizeof(txSlot*));
c_memset(property->value.table.address, 0, the->keyCount * sizeof(txSlot*));
property->value.table.length = the->keyCount;
property->kind = XS_GLOBAL_KIND;
return instance;
}
txSlot* fxNewHostInstance(txMachine* the)
{
txSlot* aPrototype;
txSlot* anInstance;
txSlot* aProperty;
aPrototype = fxGetInstance(the, the->stack);
anInstance = fxNewSlot(the);
anInstance->flag = XS_VALUE_FLAG;
anInstance->kind = XS_INSTANCE_KIND;
anInstance->value.instance.garbage = C_NULL;
anInstance->value.instance.prototype = aPrototype;
the->stack->value.reference = anInstance;
the->stack->kind = XS_REFERENCE_KIND;
aProperty = anInstance->next = fxNewSlot(the);
aProperty->ID = XS_NO_ID;
aProperty->flag = aPrototype->next->flag & ~XS_SHARED_FLAG;
aProperty->kind = XS_HOST_KIND;
aProperty->value.host.data = C_NULL;
aProperty->value.host.variant.destructor = aPrototype->next->value.host.variant.destructor;
return anInstance;
}
txSlot* fxNextHostFunctionProperty(txMachine* the, txSlot* property, txCallback call, txInteger length, txID id, txFlag flag)
{
txSlot *function, *home = the->stack, *slot;
function = fxNewHostFunction(the, call, length, id);
slot = mxFunctionInstanceHome(function);
slot->kind = home->kind;
slot->value = home->value;
property = property->next = fxNewSlot(the);
property->flag = flag;
property->ID = id;
property->kind = the->stack->kind;
property->value = the->stack->value;
the->stack++;
return property;
}
txSlot* fxNewFunctionInstance(txMachine* the)
{
txSlot* anInstance;
txSlot* aProperty;
txSlot* aPrototype;
anInstance = fxNewSlot(the);
anInstance->flag = XS_VALUE_FLAG;
anInstance->kind = XS_INSTANCE_KIND;
anInstance->value.instance.garbage = C_NULL;
anInstance->value.instance.prototype = C_NULL;
if (the->stack->kind == XS_ALIAS_KIND)
anInstance->ID = the->stack->value.alias;
else
anInstance->value.instance.prototype = the->stack->value.reference;
the->stack->value.reference = anInstance;
the->stack->kind = XS_REFERENCE_KIND;
/* CODE */
aProperty = anInstance->next = fxNewSlot(the);
aProperty->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
aProperty->kind = mxEmptyCode.kind;
aProperty->value.code = mxEmptyCode.value.code;
/* CLOSURE */
aProperty = aProperty->next = fxNewSlot(the);
aProperty->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
aProperty->kind = XS_NULL_KIND;
/* PROTOTYPE */
aProperty = aProperty->next = fxNewSlot(the);
aProperty->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG;
aPrototype = fxNewSlot(the);
aPrototype->ID = mxObjectPrototype.value.alias;
aPrototype->next = C_NULL;
aPrototype->flag = XS_NO_FLAG;
aPrototype->kind = XS_INSTANCE_KIND;
aPrototype->value.instance.garbage = C_NULL;
aPrototype->value.instance.prototype = C_NULL;
aProperty->kind = XS_REFERENCE_KIND;
aProperty->value.reference = aPrototype;
#ifdef mxProfile
/* PROFILE */
aProperty = aProperty->next = fxNewSlot(the);
aProperty->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG;
aProperty->kind = XS_INTEGER_KIND;
aProperty->value.integer = the->profileID;
the->profileID++;
#endif
return anInstance;
}
txSlot* fxNewFunctionInstance(txMachine* the, txID name)
{
txSlot* instance;
txSlot* property;
instance = fxNewObjectInstance(the);
instance->flag |= XS_VALUE_FLAG;
/* CODE */
property = instance->next = fxNewSlot(the);
property->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
property->kind = mxEmptyCode.kind;
property->value.code = mxEmptyCode.value.code;
/* CLOSURE */
property = property->next = fxNewSlot(the);
property->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
property->kind = XS_NULL_KIND;
/* PROTOTYPE */
property = property->next = fxNewSlot(the);
property->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG;
property->kind = XS_NULL_KIND;
/* HOME */
property = property->next = fxNewSlot(the);
property->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
property->kind = XS_NULL_KIND;
/* INFO */
property = property->next = fxNewSlot(the);
property->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
property->kind = XS_INFO_KIND;
property->value.info.length = -1;
property->value.info.name = name;
#ifdef mxProfile
property->value.info.profileID = the->profileID;
the->profileID++;
#endif
/* MODULE */
property = property->next = fxNewSlot(the);
property->flag = XS_DONT_DELETE_FLAG | XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG;
if (the->frame && (mxFunction->kind == XS_REFERENCE_KIND) && (mxIsFunction(mxFunction->value.reference))) {
txSlot* slot = mxFunctionInstanceModule(mxFunction->value.reference);
property->kind = slot->kind;
property->value = slot->value;
}
else
property->kind = XS_NULL_KIND;
return instance;
}