XQuilla/include/xqilla/runtime/ResultImpl.hpp
2020-02-17 22:05:20 +01:00

69 lines
2 KiB
C++

/*
* Copyright (c) 2001-2006
* DecisionSoft Limited. All rights reserved.
* Copyright (c) 2004-2006
* Progress Software Corporation. All rights reserved.
* Copyright (c) 2004-2006
* Oracle. All rights reserved.
*
* See the file LICENSE for redistribution information.
*
* $Id: ResultImpl.hpp,v 1.9 2006/11/01 16:37:15 jpcs Exp $
*/
#ifndef _RESULTIMPL_HPP
#define _RESULTIMPL_HPP
#include <string>
#include <xercesc/util/XercesDefs.hpp>
#include <xqilla/framework/XQillaExport.hpp>
#include <xqilla/items/Item.hpp>
#include <xqilla/framework/ReferenceCounted.hpp>
#include <xqilla/ast/LocationInfo.hpp>
class SequenceType;
class DynamicContext;
class Sequence;
/** A lazily evaluated query result */
class XQILLA_API ResultImpl : public ReferenceCounted, public LocationInfo
{
public:
virtual ~ResultImpl() {}
/// Get the next item from the iterator. Returns null if the is no next value.
virtual Item::Ptr next(DynamicContext *context) = 0;
/// Performs iterator specific skip of results
virtual void skip() {}
/// Returns the effective boolean value of the sequence. Only works properly before next() has been called.
virtual bool getEffectiveBooleanValue(DynamicContext* context, const LocationInfo *info);
/// Returns the effective boolean value of the sequence.
static bool getEffectiveBooleanValue(const Item::Ptr &first, const Item::Ptr &second, DynamicContext* context, const LocationInfo *info);
/// Cast operator to a Sequence. Only works properly before next() has been called.
virtual Sequence toSequence(DynamicContext *context);
/// Debug method to visualise the Result
virtual std::string asString(DynamicContext *context, int indent) const = 0;
static std::string getIndent(int indent);
protected:
/**
* Do not allocate this object from a memory manager!
* It must be created using the heap.
*/
ResultImpl(const LocationInfo *o)
{
setLocationInfo(o);
}
private:
ResultImpl(const ResultImpl &) {};
ResultImpl &operator=(const ResultImpl &) { return *this; };
};
#endif