structuralConstraintPatternHeader.h

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/**
 *
 *   Copyright (c) 2005-2021 by Pierre-Henri WUILLEMIN(@LIP6) & Christophe GONZALES(@AMU)
 *   info_at_agrum_dot_org
 *
 *  This library is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This library 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this library.  If not, see <http://www.gnu.org/licenses/>.
 *
 */


// this file should be included at the end of all the StructuralConstraints
// header files (see StructuralConstraintDAG to see how it should be included).

#ifdef GUM_CONSTRAINT_CLASS_NAME

// ##########################################################################
/// @name Accessors / Modifiers
// ##########################################################################
/// @{

/// sets a new graph from which we will perform checkings
void setGraph(const DiGraph& graph);

/// notify the constraint of a modification of the graph
/** @warning If an already existing arc is added nothing is done. In
 * particular, no exception is raised. */
void modifyGraph(const ArcAddition& change);

/// notify the constraint of a modification of the graph
/** @warning If a nonexisting arc is removed, nothing is done. In
 * particular, no exception is raised. */
void modifyGraph(const ArcDeletion& change);

/// notify the constraint of a modification of the graph
/** @warning If an already existing arc is added, or if a nonexisting arc
 * is removed, nothing is done. In particular, no exception is raised. */
void modifyGraph(const ArcReversal& change);

/// notify the constraint of a modification of the graph
/** @warning If an already existing arc is added, or if a nonexisting arc
 * is removed, nothing is done. In particular, no exception is raised. */
void modifyGraph(const GraphChange& change);

/// indicates whether a change will always violate the constraint
/** Some learning algorithms need examine several times whether a given
 * graph change can be applied. For instance, the first time arc (X,Y)
 * addition is considered, the learning algorithm may discard this change
 * because it violates the structural constraint (e.g., if the latter
 * enforces a DAG structure, this arc addition might induce a directed
 * cycle), but, later on, other arc removal may induce that the arc addition
 * is now possible. Such change is thus not always invalid. Conversely,
 * there are changes that can be discarded once and for all. For instance,
 * in a 2TBN structure, it is always impossible to add a backward-time arc.
 * Such graph changes are always invalid and are therefore tagged as such
 * by the isAlwaysInvalid method. */
bool isAlwaysInvalid(const GraphChange& change) const;

/// checks whether the constraints enable to add arc (x,y)
bool checkArcAddition(NodeId x, NodeId y) const;

/// checks whether the constraints enable to remove arc (x,y)
bool checkArcDeletion(NodeId x, NodeId y) const;

/// checks whether the constraints enable to reverse arc (x,y)
bool checkArcReversal(NodeId x, NodeId y) const;

/// checks whether the constraints enable to add an arc
bool checkModification(const ArcAddition& change) const;

/// checks whether the constraints enable to remove an arc
bool checkModification(const ArcDeletion& change) const;

/// checks whether the constraints enable to reverse an arc
bool checkModification(const ArcReversal& change) const;

/// checks whether the constraints enable to perform a graph change
bool checkModification(const GraphChange& change) const;

/// @}

#endif /* GUM_CONSTRAINT_CLASS_NAME */