TAO_Constraint_Evaluator traverse a constraint expression tree, and determines whether an offer fits the constraints represented by the tree. More...

#include <Constraint_Visitors.h>

Inheritance diagram for TAO_Constraint_Evaluator:

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Collaboration diagram for TAO_Constraint_Evaluator:

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Classes
class	Operand_Queue

Public Member Functions
	TAO_Constraint_Evaluator (void)
	Constructor. More...

CORBA::Boolean	evaluate_constraint (TAO_Constraint *root)

int	evaluate_preference (TAO_Constraint *root, TAO_Literal_Constraint &result)

virtual int	visit_constraint (TAO_Unary_Constraint *constraint)

virtual int	visit_with (TAO_Unary_Constraint *unary_with)

virtual int	visit_min (TAO_Unary_Constraint *unary_min)

virtual int	visit_max (TAO_Unary_Constraint *unary_max)

virtual int	visit_first (TAO_Noop_Constraint *noop_first)

virtual int	visit_random (TAO_Noop_Constraint *noop_random)

virtual int	visit_and (TAO_Binary_Constraint *boolean_and)

virtual int	visit_or (TAO_Binary_Constraint *boolean_or)

virtual int	visit_not (TAO_Unary_Constraint *unary_not)
	Logically negates the value of the operand. More...

virtual int	visit_exist (TAO_Unary_Constraint *unary_exist)

virtual int	visit_unary_minus (TAO_Unary_Constraint *unary_minus)
	Mathematically negates the return value the operand. More...

virtual int	visit_add (TAO_Binary_Constraint *boolean_add)
	Add the results of evaluating the left and right operands. More...

virtual int	visit_sub (TAO_Binary_Constraint *boolean_sub)
	Subtract the results of evaluating the left and right operands. More...

virtual int	visit_mult (TAO_Binary_Constraint *boolean_mult)
	Multiply the results of evaluating the left and right operands. More...

virtual int	visit_div (TAO_Binary_Constraint *boolean_div)
	Divide the results of evaluating the left and right operands. More...

virtual int	visit_twiddle (TAO_Binary_Constraint *binary_twiddle)
	Determines if the right operand is a substring of the left. More...

virtual int	visit_in (TAO_Binary_Constraint *binary_in)

virtual int	visit_less_than (TAO_Binary_Constraint *boolean_lt)

virtual int	visit_less_than_equal (TAO_Binary_Constraint *boolean_lte)

virtual int	visit_greater_than (TAO_Binary_Constraint *boolean_gt)

virtual int	visit_greater_than_equal (TAO_Binary_Constraint *boolean_gte)

virtual int	visit_equal (TAO_Binary_Constraint *boolean_eq)

virtual int	visit_not_equal (TAO_Binary_Constraint *boolean_neq)

virtual int	visit_literal (TAO_Literal_Constraint *literal)
	Copy the value of the literal into the result container. More...

virtual int	visit_property (TAO_Property_Constraint *literal)
	Copy the value of the property into the result container. More...

Public Member Functions inherited from TAO_Constraint_Visitor
virtual	~TAO_Constraint_Visitor (void)

Protected Attributes
TAO_Lookup_Table	props_
	The map of property names to their values for a property. More...

Operand_Queue	queue_
	The result of a non_boolean operation. More...

Private Member Functions
void	do_the_op (int operation)
	Method for performing a arithmetic or comparison operation. More...

int	visit_bin_op (TAO_Binary_Constraint *op, int operation)
	Method for evaluating a binary operation. More...

CORBA::Boolean	sequence_does_contain (CORBA::Any *sequence, TAO_Literal_Constraint &element)

	TAO_Constraint_Evaluator (const TAO_Constraint_Evaluator &)
	Disallow copying. More...

TAO_Constraint_Evaluator &	operator= (const TAO_Constraint_Evaluator &)

Detailed Description

TAO_Constraint_Evaluator traverse a constraint expression tree, and determines whether an offer fits the constraints represented by the tree.

Using the Visitor pattern, the TAO_Constraint_Evaluator has each node of the expression tree call back to it with the method designated for its type. In that method, the visitor will evaluate its operands and perform the operation designated by that node's type, and return the result. Note: the TAO_Constraint_Evaluator assumes the tree is semantically correct, that is, the validate method on TAO_Constraint_Validator return true. The only possible evaluation time errors are a divide by a property whose value is zero and undefined properties.

Constructor & Destructor Documentation

TAO_Constraint_Evaluator::TAO_Constraint_Evaluator ( void )

Constructor.

TAO_Constraint_Evaluator::TAO_Constraint_Evaluator ( const TAO_Constraint_Evaluator & )

private

Disallow copying.

Member Function Documentation

void TAO_Constraint_Evaluator::do_the_op ( int operation )

private

Method for performing a arithmetic or comparison operation.

CORBA::Boolean TAO_Constraint_Evaluator::evaluate_constraint ( TAO_Constraint * root )

Evaluate returns 1 if the offer satisfies the constraints represented by the the expression tree rooted at <root>, 0 if it doesn't. If an error occurs during process, the constraint automatically fails.

int TAO_Constraint_Evaluator::evaluate_preference	(	TAO_Constraint *	root,
		TAO_Literal_Constraint &	result
	)

The result of the preference evaluation is stored in result. The method returns 0 upon success, -1 upon failure.

TAO_Constraint_Evaluator& TAO_Constraint_Evaluator::operator= ( const TAO_Constraint_Evaluator & )

private

CORBA::Boolean TAO_Constraint_Evaluator::sequence_does_contain	(	CORBA::Any *	sequence,
		TAO_Literal_Constraint &	element
	)

private

Determine if sequence contains element, a literal of the same simple type as <sequence_type>. Return true in this eventuality.

int TAO_Constraint_Evaluator::visit_add ( TAO_Binary_Constraint * boolean_add )

virtual

Add the results of evaluating the left and right operands.

Classes

Public Member Functions

Protected Attributes

Private Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation