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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 Visitor base class for working with the component tree.
*/
#ifndef COMPONENTVISITOR_H
#define COMPONENTVISITOR_H
namespace ue2 {
class AsciiComponentClass;
class Component;
class ComponentAlternation;
class ComponentAssertion;
class ComponentAtomicGroup;
class ComponentBackReference;
class ComponentBoundary;
class ComponentByte;
class ComponentClass;
class ComponentCondReference;
class ComponentEmpty;
class ComponentEUS;
class ComponentRepeat;
class ComponentSequence;
class ComponentWordBoundary;
class UTF8ComponentClass;
/**
* \brief Visitor base class for working with the component tree.
*
* Our approach to implementing the visitor pattern for traversing (and
* optionally mutating) the Component tree for a pattern. Each _visit_ function
* takes a Component subclass pointer in and returns a Component pointer. That
* pointer can have several values, dictating what the containing Component
* should do:
*
* 1. If ptr == c, then do nothing.
* 2. If ptr == nullptr, then remove c from the tree.
* 3. If ptr != c && ptr != nullptr, then replace c with ptr.
*
* Traversal order is pre-order.
*
* After a Component's subcomponents have been visited, the _post_ function for
* that Component will be called.
*/
class ComponentVisitor {
public:
virtual ~ComponentVisitor();
virtual Component *visit(AsciiComponentClass *c) = 0;
virtual Component *visit(ComponentAlternation *c) = 0;
virtual Component *visit(ComponentAssertion *c) = 0;
virtual Component *visit(ComponentAtomicGroup *c) = 0;
virtual Component *visit(ComponentBackReference *c) = 0;
virtual Component *visit(ComponentBoundary *c) = 0;
virtual Component *visit(ComponentByte *c) = 0;
virtual Component *visit(ComponentCondReference *c) = 0;
virtual Component *visit(ComponentEmpty *c) = 0;
virtual Component *visit(ComponentEUS *c) = 0;
virtual Component *visit(ComponentRepeat *c) = 0;
virtual Component *visit(ComponentSequence *c) = 0;
virtual Component *visit(ComponentWordBoundary *c) = 0;
virtual Component *visit(UTF8ComponentClass *c) = 0;
virtual void post(AsciiComponentClass *c) = 0;
virtual void post(ComponentAlternation *c) = 0;
virtual void post(ComponentAssertion *c) = 0;
virtual void post(ComponentAtomicGroup *c) = 0;
virtual void post(ComponentBackReference *c) = 0;
virtual void post(ComponentBoundary *c) = 0;
virtual void post(ComponentByte *c) = 0;
virtual void post(ComponentCondReference *c) = 0;
virtual void post(ComponentEmpty *c) = 0;
virtual void post(ComponentEUS *c) = 0;
virtual void post(ComponentRepeat *c) = 0;
virtual void post(ComponentSequence *c) = 0;
virtual void post(ComponentWordBoundary *c) = 0;
virtual void post(UTF8ComponentClass *c) = 0;
};
/**
* \brief Concrete subclass of ComponentVisitor with default behaviour,
* allowing you to just implement the member functions you need.
*/
class DefaultComponentVisitor : public ComponentVisitor {
public:
DefaultComponentVisitor();
~DefaultComponentVisitor() override;
Component *visit(AsciiComponentClass *c) override;
Component *visit(ComponentAlternation *c) override;
Component *visit(ComponentAssertion *c) override;
Component *visit(ComponentAtomicGroup *c) override;
Component *visit(ComponentBackReference *c) override;
Component *visit(ComponentBoundary *c) override;
Component *visit(ComponentByte *c) override;
Component *visit(ComponentCondReference *c) override;
Component *visit(ComponentEmpty *c) override;
Component *visit(ComponentEUS *c) override;
Component *visit(ComponentRepeat *c) override;
Component *visit(ComponentSequence *c) override;
Component *visit(ComponentWordBoundary *c) override;
Component *visit(UTF8ComponentClass *c) override;
void post(AsciiComponentClass *c) override;
void post(ComponentAlternation *c) override;
void post(ComponentAssertion *c) override;
void post(ComponentAtomicGroup *c) override;
void post(ComponentBackReference *c) override;
void post(ComponentBoundary *c) override;
void post(ComponentByte *c) override;
void post(ComponentCondReference *c) override;
void post(ComponentEmpty *c) override;
void post(ComponentEUS *c) override;
void post(ComponentRepeat *c) override;
void post(ComponentSequence *c) override;
void post(ComponentWordBoundary *c) override;
void post(UTF8ComponentClass *c) override;
};
} // namespace ue2
#endif // COMPONENTVISITOR_H
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