#include "../config/pathan_config.h"
/*
 * Copyright (c) 2001, DecisionSoft Limited All rights reserved.
 * Please see LICENSE.TXT for more information.
 */

#include <pathan/functions/FunctionExists.hpp>
#include <pathan/ATBooleanOrDerived.hpp>
#include <pathan/DynamicContext.hpp>
#include <pathan/internal/factory/DatatypeFactory.hpp>


const XMLCh FunctionExists::name[] = {
XERCES_CPP_NAMESPACE_QUALIFIER chLatin_e, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_x, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_i, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_s, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_t, XERCES_CPP_NAMESPACE_QUALIFIER chLatin_s, XERCES_CPP_NAMESPACE_QUALIFIER chNull };

/*
 * fn:exists($arg as item()*) as xs:boolean
 */

FunctionExists::FunctionExists(const VectorOfDataItems &args, XPath2MemoryManager* memMgr)
  : ConstantFoldingFunction(name,1, 1, "item()*", args, memMgr)
{
}

Sequence FunctionExists::collapseTreeInternal(DynamicContext* context, int flags) const
{
	Sequence items=getParamNumber(1,context,DataItem::UNORDERED|DataItem::RETURN_ONE);
	return Sequence(DatatypeFactory::POD2AT::createBoolean(context->getMemoryManager(), !items.isEmpty(), context),
                  context->getMemoryManager());
}