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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 Represents an empty regex element, like (?m)
*/
#include <cassert>
#include "ComponentEmpty.h"
#include "position.h"
#include "position_info.h"
#include "buildstate.h"
#include "ue2common.h"
using namespace std;
namespace ue2 {
ComponentEmpty::ComponentEmpty() {
// Surprise, it's EMPTY!
}
ComponentEmpty::~ComponentEmpty() {
// Surprise, it's EMPTY!
}
ComponentEmpty *ComponentEmpty::clone() const { return new ComponentEmpty(); }
bool ComponentEmpty::empty() const {
return true;
}
bool ComponentEmpty::vacuous_everywhere(void) const {
return true;
}
bool ComponentEmpty::repeatable() const {
// This is the whole point of this class. Empty constructs like '(?m)' are
// not repeatable.
return false;
}
vector<PositionInfo> ComponentEmpty::first() const {
return vector<PositionInfo>(1, GlushkovBuildState::POS_EPSILON);
}
vector<PositionInfo> ComponentEmpty::last() const {
return vector<PositionInfo>();
}
void ComponentEmpty::notePositions(GlushkovBuildState &) {
// Nothing to do.
}
void ComponentEmpty::buildFollowSet(GlushkovBuildState &,
const vector<PositionInfo> &) {
// Nothing to do.
}
bool ComponentEmpty::checkEmbeddedStartAnchor(bool at_start) const {
return at_start;
}
bool ComponentEmpty::checkEmbeddedEndAnchor(bool at_end) const {
return at_end;
}
} // namespace ue2
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