Detailed Description

This is the base class for all expressions that are not variables.

It provides a basic 'CastToVar()' implementation.

The class of expressions represent two types of objects: variables and subclasses of BaseIntExpr. Variables are stateful objects that provide a rich API (remove values, WhenBound...). On the other hand, subclasses of BaseIntExpr represent range-only stateless objects. That is, min(A + B) is recomputed each time as min(A) + min(B).

Furthermore, sometimes, the propagation on an expression is not complete, and Min(), Max() are not monotonic with respect to SetMin() and SetMax(). For instance, if A is a var with domain [0 .. 5], and B another variable with domain [0 .. 5], then Plus(A, B) has domain [0, 10].

If we apply SetMax(Plus(A, B), 4)), we will deduce that both A and B have domain [0 .. 4]. In that case, Max(Plus(A, B)) is 8 and not 4. To get back monotonicity, we 'cast' the expression into a variable using the Var() method (that will call CastToVar() internally). The resulting variable will be stateful and monotonic.

Finally, one should never store a pointer to a IntExpr, or BaseIntExpr in the code. The safe code should always call Var() on an expression built by the solver, and store the object as an IntVar*. This is a consequence of the stateless nature of the expressions that makes the code error-prone.

Definition at line 109 of file constraint_solveri.h.

Public Member Functions
	BaseIntExpr (Solver *const s)

	~BaseIntExpr () override

IntVar *	Var () override
	Creates a variable from the expression. More...

virtual IntVar *	CastToVar ()

virtual int64	Min () const =0

virtual void	SetMin (int64 m)=0

virtual int64	Max () const =0

virtual void	SetMax (int64 m)=0

virtual void	Range (int64 l, int64 u)
	By default calls Min() and Max(), but can be redefined when Min and Max code can be factorized. More...

virtual void	SetRange (int64 l, int64 u)
	This method sets both the min and the max of the expression. More...

virtual void	SetValue (int64 v)
	This method sets the value of the expression. More...

virtual bool	Bound () const
	Returns true if the min and the max of the expression are equal. More...

virtual bool	IsVar () const
	Returns true if the expression is indeed a variable. More...

IntVar *	VarWithName (const std::string &name)
	Creates a variable from the expression and set the name of the resulting var. More...

virtual void	WhenRange (Demon *d)=0
	Attach a demon that will watch the min or the max of the expression. More...

void	WhenRange (Solver::Closure closure)
	Attach a demon that will watch the min or the max of the expression. More...

void	WhenRange (Solver::Action action)
	Attach a demon that will watch the min or the max of the expression. More...

virtual void	Accept (ModelVisitor *const visitor) const
	Accepts the given visitor. More...

std::string	DebugString () const override

Solver *	solver () const

void	FreezeQueue ()
	This method freezes the propagation queue. More...

void	UnfreezeQueue ()
	This method unfreezes the propagation queue. More...

void	EnqueueDelayedDemon (Demon *const d)
	This method pushes the demon onto the propagation queue. More...

void	EnqueueVar (Demon *const d)

void	ExecuteAll (const SimpleRevFIFO< Demon * > &demons)

void	EnqueueAll (const SimpleRevFIFO< Demon * > &demons)

void	set_action_on_fail (Solver::Action a)

void	reset_action_on_fail ()
	This method clears the failure callback. More...

void	set_variable_to_clean_on_fail (IntVar *v)
	Shortcut for variable cleaner. More...

virtual std::string	name () const
	Object naming. More...

void	set_name (const std::string &name)

bool	HasName () const
	Returns whether the object has been named or not. More...

virtual std::string	BaseName () const
	Returns a base name for automatic naming. More...

Constructor & Destructor Documentation

◆ BaseIntExpr()

operations_research::BaseIntExpr::BaseIntExpr ( Solver *const s )

inlineexplicit

Definition at line 111 of file constraint_solveri.h.

◆ ~BaseIntExpr()

operations_research::BaseIntExpr::~BaseIntExpr ( )

inlineoverride

Definition at line 112 of file constraint_solveri.h.

Member Function Documentation

◆ Accept()

virtual void operations_research::IntExpr::Accept ( ModelVisitor *const visitor ) const

virtualinherited

Accepts the given visitor.

Reimplemented in operations_research::IntVar.

◆ BaseName()

virtual std::string operations_research::PropagationBaseObject::BaseName ( ) const

virtualinherited

Returns a base name for automatic naming.

Reimplemented in operations_research::BooleanVar.

◆ Bound()

virtual bool operations_research::IntExpr::Bound ( ) const

inlinevirtualinherited

Returns true if the min and the max of the expression are equal.

Reimplemented in operations_research::BooleanVar.

Definition at line 3799 of file constraint_solver.h.

◆ CastToVar()

virtual IntVar* operations_research::BaseIntExpr::CastToVar ( )

virtual

◆ DebugString()

std::string operations_research::PropagationBaseObject::DebugString ( ) const

inlineoverridevirtualinherited

Reimplemented from operations_research::BaseObject.

Reimplemented in operations_research::Pack, operations_research::Assignment, operations_research::SequenceVar, operations_research::Constraint, and operations_research::BooleanVar.

Definition at line 3109 of file constraint_solver.h.

◆ EnqueueAll()

void operations_research::PropagationBaseObject::EnqueueAll ( const SimpleRevFIFO< Demon * > & demons )

inherited

◆ EnqueueDelayedDemon()

void operations_research::PropagationBaseObject::EnqueueDelayedDemon ( Demon *const d )

inlineinherited

This method pushes the demon onto the propagation queue.

It will be processed directly if the queue is empty. It will be enqueued according to its priority otherwise.

Definition at line 3129 of file constraint_solver.h.

◆ EnqueueVar()

void operations_research::PropagationBaseObject::EnqueueVar ( Demon *const d )

inlineinherited

Definition at line 3130 of file constraint_solver.h.

◆ ExecuteAll()

void operations_research::PropagationBaseObject::ExecuteAll ( const SimpleRevFIFO< Demon * > & demons )

inherited

◆ FreezeQueue()

void operations_research::PropagationBaseObject::FreezeQueue ( )

inlineinherited

This method freezes the propagation queue.

It is useful when you need to apply multiple modifications at once.

Definition at line 3120 of file constraint_solver.h.

◆ HasName()

bool operations_research::PropagationBaseObject::HasName ( ) const

inherited

Returns whether the object has been named or not.

◆ IsVar()

virtual bool operations_research::IntExpr::IsVar ( ) const

inlinevirtualinherited

Returns true if the expression is indeed a variable.

Reimplemented in operations_research::IntVar.

Definition at line 3802 of file constraint_solver.h.

◆ Max()

virtual int64 operations_research::IntExpr::Max ( ) const

pure virtualinherited

Implemented in operations_research::BooleanVar.

◆ Min()

virtual int64 operations_research::IntExpr::Min ( ) const

pure virtualinherited

Implemented in operations_research::BooleanVar.

◆ name()

virtual std::string operations_research::PropagationBaseObject::name ( ) const

virtualinherited

Object naming.

◆ Range()

virtual void operations_research::IntExpr::Range	(	int64 *	l,
		int64 *	u
	)

inlinevirtualinherited

By default calls Min() and Max(), but can be redefined when Min and Max code can be factorized.

Definition at line 3785 of file constraint_solver.h.

◆ reset_action_on_fail()

void operations_research::PropagationBaseObject::reset_action_on_fail ( )

inlineinherited

This method clears the failure callback.

Definition at line 3143 of file constraint_solver.h.

◆ set_action_on_fail()

void operations_research::PropagationBaseObject::set_action_on_fail ( Solver::Action a )

inlineinherited

Definition at line 3137 of file constraint_solver.h.

◆ set_name()

void operations_research::PropagationBaseObject::set_name ( const std::string & name )

inherited

◆ set_variable_to_clean_on_fail()

void operations_research::PropagationBaseObject::set_variable_to_clean_on_fail ( IntVar * v )

inlineinherited

Shortcut for variable cleaner.

Definition at line 3146 of file constraint_solver.h.

◆ SetMax()

virtual void operations_research::IntExpr::SetMax ( int64 m )

pure virtualinherited

Implemented in operations_research::BooleanVar.

◆ SetMin()

virtual void operations_research::IntExpr::SetMin ( int64 m )

pure virtualinherited

Implemented in operations_research::BooleanVar.

◆ SetRange()

virtual void operations_research::IntExpr::SetRange	(	int64	l,
		int64	u
	)

inlinevirtualinherited

This method sets both the min and the max of the expression.

Reimplemented in operations_research::BooleanVar.

Definition at line 3790 of file constraint_solver.h.

◆ SetValue()

virtual void operations_research::IntExpr::SetValue ( int64 v )

inlinevirtualinherited

This method sets the value of the expression.

Definition at line 3796 of file constraint_solver.h.

◆ solver()

Solver* operations_research::PropagationBaseObject::solver ( ) const

inlineinherited

Definition at line 3116 of file constraint_solver.h.

◆ UnfreezeQueue()

void operations_research::PropagationBaseObject::UnfreezeQueue ( )

inlineinherited

This method unfreezes the propagation queue.

All modifications that happened when the queue was frozen will be processed.

Definition at line 3124 of file constraint_solver.h.

◆ Var()

IntVar* operations_research::BaseIntExpr::Var ( )

overridevirtual

Creates a variable from the expression.

Implements operations_research::IntExpr.

◆ VarWithName()

IntVar* operations_research::IntExpr::VarWithName ( const std::string & name )

inherited

Creates a variable from the expression and set the name of the resulting var.

If the expression is already a variable, then it will set the name of the expression, possibly overwriting it. This is just a shortcut to Var() followed by set_name().

◆ WhenRange() [1/3]

virtual void operations_research::IntExpr::WhenRange ( Demon * d )

pure virtualinherited

Attach a demon that will watch the min or the max of the expression.

Implemented in operations_research::BooleanVar.

◆ WhenRange() [2/3]

void operations_research::IntExpr::WhenRange ( Solver::Closure closure )

inlineinherited

Attach a demon that will watch the min or the max of the expression.

Definition at line 3816 of file constraint_solver.h.

◆ WhenRange() [3/3]

void operations_research::IntExpr::WhenRange ( Solver::Action action )

inlineinherited

Attach a demon that will watch the min or the max of the expression.

Definition at line 3822 of file constraint_solver.h.

The documentation for this class was generated from the following file:

constraint_solveri.h

Detailed Description

Public Member Functions

Constructor & Destructor Documentation

◆ BaseIntExpr()

◆ ~BaseIntExpr()

Member Function Documentation

◆ Accept()

◆ BaseName()

◆ Bound()

◆ CastToVar()

◆ DebugString()

◆ EnqueueAll()

◆ EnqueueDelayedDemon()

◆ EnqueueVar()

◆ ExecuteAll()

◆ FreezeQueue()

◆ HasName()

◆ IsVar()

◆ Max()

◆ Min()

◆ name()

◆ Range()

◆ reset_action_on_fail()

◆ set_action_on_fail()

◆ set_name()

◆ set_variable_to_clean_on_fail()

◆ SetMax()

◆ SetMin()

◆ SetRange()

◆ SetValue()

◆ solver()

◆ UnfreezeQueue()

◆ Var()

◆ VarWithName()

◆ WhenRange() [1/3]

◆ WhenRange() [2/3]

◆ WhenRange() [3/3]