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/*
* Copyright (c) 2015, Intel Corporation
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Intel Corporation nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/** \file
* \brief Repeats ('*', '+', '?', '{M,N}', etc)
*/
#ifndef RE_COMPONENTREPEAT_H
#define RE_COMPONENTREPEAT_H
#include "Component.h"
#include "position.h"
#include "ue2common.h"
#include <memory>
#include <utility>
namespace ue2 {
/**
* \brief Encapsulates a repeat of a subexpression ('*', '+', '?', '{M,N}',
* etc).
*
* ASCII Art Time:
*
* Our standard representation of standard repeats. Other constructions (fan-in
* vs fan-out) would also be possible and equivalent for our purposes.
*
* {n,m}
*
* S->M->M->M->O->O->O->T
* | ^ ^ ^
* | | | |
* \-----------/
*
* {0,m}
*
* /-----------\
* | |
* | V
* S->O->O->O->T
* | ^ ^ ^
* | | | |
* \--------/
*
*/
class ComponentRepeat : public Component {
friend class ConstructLiteralVisitor;
friend class DumpVisitor;
friend class PrintVisitor;
friend class SimplifyVisitor;
public:
/** \brief Value representing no maximum bound. */
static constexpr u32 NoLimit = 0xffffffff;
/** \brief Type of this repeat, characterising its
* greediness/possessiveness. */
enum RepeatType {
/** Minimising repeat, like 'a*?'. */
REPEAT_NONGREEDY,
/** Maximising repeat, like 'a*'. This is the default in PCRE. */
REPEAT_GREEDY,
/** Possessive, maximising repeat, like 'a*+'. Possessive repeats are
* only currently supported in prefiltering mode, where we treat them
* the same way we treat normal greedy repeats. */
REPEAT_POSSESSIVE,
};
ComponentRepeat(std::unique_ptr<Component> sub_comp, u32 min, u32 max,
RepeatType t);
~ComponentRepeat() override;
ComponentRepeat *clone() const override;
Component *accept(ComponentVisitor &v) override;
void accept(ConstComponentVisitor &v) const override;
std::vector<PositionInfo> first() const override;
std::vector<PositionInfo> last() const override;
bool empty() const override;
bool repeatable() const override;
bool vacuous_everywhere() const override;
void notePositions(GlushkovBuildState &bs) override;
void buildFollowSet(GlushkovBuildState &bs,
const std::vector<PositionInfo> &lastPos) override;
bool checkEmbeddedStartAnchor(bool at_start) const override;
bool checkEmbeddedEndAnchor(bool at_end) const override;
void optimise(bool connected_to_sds) override;
virtual std::pair<u32, u32> getBounds() const {
return std::make_pair(m_min, m_max);
}
/** \brief From declared behaviour (not taking into account the
* sub-component). */
enum RepeatType type;
protected:
void postSubNotePositionHook();
void wireRepeats(GlushkovBuildState &bs);
std::unique_ptr<Component> sub_comp;
u32 m_min;
u32 m_max;
std::vector<std::vector<PositionInfo> > m_firsts;
std::vector<std::vector<PositionInfo> > m_lasts;
Position posFirst;
Position posLast;
ComponentRepeat(const ComponentRepeat &other);
};
std::unique_ptr<ComponentRepeat>
makeComponentRepeat(std::unique_ptr<Component> sub_comp, u32 min, u32 max,
ComponentRepeat::RepeatType t);
} // namespace ue2
#endif // _RE_COMPONENTREPEAT_H_
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