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/**************************************************************************
* *
* Regina - A Normal Surface Theory Calculator *
* Computational Engine *
* *
* Copyright (c) 1999-2011, Ben Burton *
* For further details contact Ben Burton (bab@debian.org). *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License as *
* published by the Free Software Foundation; either version 2 of the *
* License, or (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, but *
* WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* General Public License for more details. *
* *
* You should have received a copy of the GNU General Public *
* License along with this program; if not, write to the Free *
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, *
* MA 02110-1301, USA. *
* *
**************************************************************************/
/* end stub */
/*! \file subcomplex/nstandardtri.h
* \brief Deals with triangulations whose structures are well-understood.
*/
#ifndef __NSTANDARDTRI_H
#ifndef __DOXYGEN
#define __NSTANDARDTRI_H
#endif
#include "regina-core.h"
#include "shareableobject.h"
namespace regina {
class NAbelianGroup;
class NComponent;
class NManifold;
class NTriangulation;
/**
* \addtogroup subcomplex Standard Triangulations and Subcomplexes
* Standard triangulations and subcomplexes of triangulations whose
* structures are well-understood.
* @{
*/
/**
* Describes a triangulation or subcomplex of a triangulation whose structure
* is well-understood. An NStandardTriangulation is generally connected
* with a real triangulation, i.e., an NTriangulation object, which it
* describes some portion of.
*
* In general NStandardTriangulation objects cannot be constructed
* directly, but are instead created through static identification
* routines such as
* NStandardTriangulation::isStandardTriangulation(NTriangulation*).
*
* Subclasses corresponding to different families of triangulations do
* not need to override writeTextShort() since this routine is
* properly implemented in the base class NStandardTriangulation.
*
* \testpart
*/
class REGINA_API NStandardTriangulation : public ShareableObject {
public:
/**
* A destructor that does nothing.
*/
virtual ~NStandardTriangulation();
/**
* Returns the name of this specific triangulation as a
* human-readable string.
*
* @return the name of this triangulation.
*/
std::string getName() const;
/**
* Returns the name of this specific triangulation in TeX
* format. No leading or trailing dollar signs will be included.
*
* \warning The behaviour of this routine has changed as of
* Regina 4.3; in earlier versions, leading and trailing dollar
* signs were provided.
*
* @return the name of this triangulation in TeX format.
*/
std::string getTeXName() const;
/**
* Returns the 3-manifold represented by this triangulation, if
* such a recognition routine has been implemented. If the
* 3-manifold cannot be recognised then this routine will return 0.
*
* The details of which standard triangulations have 3-manifold
* recognition routines can be found in the notes for the
* corresponding subclasses of NStandardTriangulation. The
* default implementation of this routine returns 0.
*
* It is expected that the number of triangulations whose
* underlying 3-manifolds can be recognised will grow between
* releases.
*
* The 3-manifold will be newly allocated and must be destroyed
* by the caller of this routine.
*
* @return the underlying 3-manifold.
*/
virtual NManifold* getManifold() const;
/**
* Returns the expected first homology group of this triangulation,
* if such a routine has been implemented. If the calculation of
* homology has not yet been implemented for this triangulation
* then this routine will return 0.
*
* This routine does not work by calling
* NTriangulation::getHomologyH1() on the associated real
* triangulation. Instead the homology is calculated directly
* from the known properties of this standard triangulation.
*
* The details of which standard triangulations have homology
* calculation routines can be found in the notes for the
* corresponding subclasses of NStandardTriangulation. The
* default implementation of this routine returns 0.
*
* The homology group will be newly allocated and must be
* destroyed by the caller of this routine.
*
* If this NStandardTriangulation describes an entire NTriangulation
* (and not just a part thereof) then the results of this routine
* should be identical to the homology group obtained by calling
* NTriangulation::getHomologyH1() upon the associated real
* triangulation.
*
* @return the first homology group of this triangulation, or 0 if
* the appropriate calculation routine has not yet been implemented.
*/
virtual NAbelianGroup* getHomologyH1() const;
/**
* Writes the name of this triangulation as a human-readable
* string to the given output stream.
*
* \ifacespython The parameter \a out does not exist; standard
* output will be used.
*
* @param out the output stream to which to write.
* @return a reference to the given output stream.
*/
virtual std::ostream& writeName(std::ostream& out) const = 0;
/**
* Writes the name of this triangulation in TeX format
* to the given output stream. No leading or trailing dollar
* signs will be included.
*
* \warning The behaviour of this routine has changed as of
* Regina 4.3; in earlier versions, leading and trailing dollar
* signs were provided.
*
* \ifacespython The parameter \a out does not exist; standard
* output will be used.
*
* @param out the output stream to which to write.
* @return a reference to the given output stream.
*/
virtual std::ostream& writeTeXName(std::ostream& out) const = 0;
virtual void writeTextShort(std::ostream& out) const;
/**
* Determines whether the given component represents one of the
* standard triangulations understood by Regina. The list of
* recognised triangulations is expected to grow between
* releases.
*
* If the standard triangulation returned has boundary faces
* then the given component must have the same corresponding
* boundary faces, i.e., the component cannot have any further
* identifications of these boundary faces with each other.
*
* Note that the triangulation-based routine
* isStandardTriangulation(NTriangulation*) may recognise more
* triangulations than this routine, since passing an entire
* triangulation allows access to more information.
*
* @param component the triangulation component under examination.
* @return the details of the standard triangulation if the
* given component is recognised, or 0 otherwise.
*/
static NStandardTriangulation* isStandardTriangulation(
NComponent* component);
/**
* Determines whether the given triangulation represents one of the
* standard triangulations understood by Regina. The list of
* recognised triangulations is expected to grow between
* releases.
*
* If the standard triangulation returned has boundary faces
* then the given triangulation must have the same corresponding
* boundary faces, i.e., the triangulation cannot have any further
* identifications of these boundary faces with each other.
*
* This routine may recognise more triangulations than the
* component-based isStandardTriangulation(NComponent*),
* since passing an entire triangulation allows access to
* more information.
*
* @param tri the triangulation under examination.
* @return the details of the standard triangualation if the
* given triangulation is recognised, or 0 otherwise.
*/
static NStandardTriangulation* isStandardTriangulation(
NTriangulation* tri);
};
/*@}*/
// Inline functions for NStandardTriangulation
inline NStandardTriangulation::~NStandardTriangulation() {
}
inline NManifold* NStandardTriangulation::getManifold() const {
return 0;
}
inline NAbelianGroup* NStandardTriangulation::getHomologyH1() const {
return 0;
}
inline void NStandardTriangulation::writeTextShort(std::ostream& out) const {
writeName(out);
}
} // namespace regina
#endif
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