Evaluate a constraint expression. More...

#include <ConstraintEvaluator.h>

Public Types
typedef std::vector< Clause * >::const_iterator	Clause_citer

typedef std::vector< Clause * >::iterator	Clause_iter

typedef std::vector< BaseType * >::const_iterator	Constants_citer

typedef std::vector< BaseType * >::iterator	Constants_iter

Public Member Functions
void	append_clause (int op, rvalue arg1, rvalue_list arg2)
	Add a clause to a constraint expression. More...

void	append_clause (bool_func func, rvalue_list *args)
	Add a clause to a constraint expression. More...

void	append_clause (btp_func func, rvalue_list *args)
	Add a clause to a constraint expression. More...

void	append_constant (BaseType *btp)

bool	boolean_expression ()
	Does the current constraint expression return a boolean value? More...

Clause_iter	clause_begin ()

Clause_iter	clause_end ()

bool	clause_value (Clause_iter &i, DDS &dds)

BaseType *	eval_function (DDS &dds, const std::string &dataset)
	Evaluate a function-valued constraint expression. More...

DDS *	eval_function_clauses (DDS &dds)
	Evaluate a function-valued constraint expression that contains several function calls. More...

DataDDS *	eval_function_clauses (DataDDS &dds)
	Evaluate a function-valued constraint expression that contains several function calls. Takes and returns a DataDDS. More...

bool	eval_selection (DDS &dds, const std::string &dataset)
	Evaluate a boolean-valued constraint expression. This is main method for the evaluator and is called by the BaseType::serialize() methods. More...

bool	find_function (const std::string &name, bool_func *f) const
	Find a Boolean function with a given name in the function list. More...

bool	find_function (const std::string &name, btp_func *f) const
	Find a BaseType function with a given name in the function list. More...

bool	find_function (const std::string &name, proj_func *f) const
	Find a projection function with a given name in the function list. More...

bool	function_clauses ()
	Does the current constraint expression contain function clauses. More...

bool	functional_expression ()
	Does the current constraint expression return a BaseType pointer? This method does not evaluate the clause, it provides information to the evaluator regarding how to evaluate the clause. More...

void	parse_constraint (const std::string &constraint, DDS &dds)
	Parse the constraint expression given the current DDS. More...

Friends
class	func_name_is

Detailed Description

Evaluate a constraint expression.

Definition at line 42 of file ConstraintEvaluator.h.

Member Function Documentation

◆ append_clause() [1/3]

void libdap::ConstraintEvaluator::append_clause	(	int	op,
		rvalue *	arg1,
		rvalue_list *	arg2
	)

Add a clause to a constraint expression.

This function adds an operator clause to the constraint expression.

Parameters

op	An integer indicating the operator in use. These values are generated by `bison`.
arg1	A pointer to the argument on the left side of the operator.
arg2	A pointer to a list of the arguments on the right side of the operator.

Definition at line 113 of file ConstraintEvaluator.cc.

◆ append_clause() [2/3]

void libdap::ConstraintEvaluator::append_clause	(	bool_func	func,
		rvalue_list *	args
	)

Add a clause to a constraint expression.

This function adds a boolean function clause to the constraint expression.

Parameters

func	A pointer to a boolean function from the list of supported functions.
args	A list of arguments to that function.

Definition at line 129 of file ConstraintEvaluator.cc.

◆ append_clause() [3/3]

void libdap::ConstraintEvaluator::append_clause	(	btp_func	func,
		rvalue_list *	args
	)

Add a clause to a constraint expression.

This function adds a real-valued (BaseType) function clause to the constraint expression.

Parameters

func	A pointer to a BaseType function from the list of supported functions.
args	A list of arguments to that function.

Definition at line 145 of file ConstraintEvaluator.cc.

◆ append_constant()

void libdap::ConstraintEvaluator::append_constant ( BaseType * btp )

The Constraint Evaluator maintains a list of BaseType pointers for all the constants that the constraint expression parser generates. These objects are deleted by the Constraint Evaluator destructor. Note that there are no list accessors; these constants are never accessed from the list. The list is simply a convenient way to make sure the constants are disposed of properly.

Definition at line 159 of file ConstraintEvaluator.cc.

◆ boolean_expression()

bool libdap::ConstraintEvaluator::boolean_expression ( )

Does the current constraint expression return a boolean value?

Definition at line 309 of file ConstraintEvaluator.cc.

◆ clause_begin()

ConstraintEvaluator::Clause_iter libdap::ConstraintEvaluator::clause_begin ( )

Returns the first clause in a parsed constraint expression.

Definition at line 79 of file ConstraintEvaluator.cc.

◆ clause_end()

ConstraintEvaluator::Clause_iter libdap::ConstraintEvaluator::clause_end ( )

Returns a reference to the end of the list of clauses in a parsed constraint expression. It does not reference the last clause

Definition at line 86 of file ConstraintEvaluator.cc.

◆ clause_value()

bool libdap::ConstraintEvaluator::clause_value	(	Clause_iter &	iter,
		DDS &	dds
	)

Returns the value of the indicated clause of a constraint expression.

Definition at line 93 of file ConstraintEvaluator.cc.

◆ eval_function()

BaseType * libdap::ConstraintEvaluator::eval_function	(	DDS &	dds,
		const std::string &	dataset
	)

Evaluate a function-valued constraint expression.

Deprecated:

Definition at line 204 of file ConstraintEvaluator.cc.

◆ eval_function_clauses() [1/2]

DDS * libdap::ConstraintEvaluator::eval_function_clauses ( DDS & dds )

Evaluate a function-valued constraint expression that contains several function calls.

This method can be called for any function-valued constraint expression. Unlike eval_function(), it will package the return value in a new DDS object. The server should free this object once it has been serialized and sent.

Note: While there is another type of function that can appear in a CE (a 'projection function') those are evaluated by the ce parser - they are used to insert new variables into the DDS as a side effect of CE evaluation. That kind of function can never appear here; these are all functions that return BaseType pointers.; Added for libdap 3.11

Definition at line 256 of file ConstraintEvaluator.cc.

◆ eval_function_clauses() [2/2]

DataDDS * libdap::ConstraintEvaluator::eval_function_clauses ( DataDDS & dds )

Evaluate a function-valued constraint expression that contains several function calls. Takes and returns a DataDDS.

See also: ConstraintEvaluator::eval_function_clauses(DataDDS &dds)

Note: Added for libdap 3.11

Definition at line 285 of file ConstraintEvaluator.cc.

◆ eval_selection()

bool libdap::ConstraintEvaluator::eval_selection	(	DDS &	dds,
		const std::string &	dataset
	)

Evaluate a boolean-valued constraint expression. This is main method for the evaluator and is called by the BaseType::serialize() methods.

Parameters

dds	Use these variables when evaluating the expressions.
dataset	This string is passed to the read() methods.

Returns: True if the expression is true, false otherwise.

Definition at line 329 of file ConstraintEvaluator.cc.

◆ find_function() [1/3]

bool libdap::ConstraintEvaluator::find_function	(	const std::string &	name,
		bool_func *	f
	)		const

Find a Boolean function with a given name in the function list.

Definition at line 165 of file ConstraintEvaluator.cc.

◆ find_function() [2/3]

bool libdap::ConstraintEvaluator::find_function	(	const std::string &	name,
		btp_func *	f
	)		const

Find a BaseType function with a given name in the function list.

Definition at line 171 of file ConstraintEvaluator.cc.

◆ find_function() [3/3]

bool libdap::ConstraintEvaluator::find_function	(	const std::string &	name,
		proj_func *	f
	)		const

Find a projection function with a given name in the function list.

Definition at line 177 of file ConstraintEvaluator.cc.

◆ function_clauses()

bool libdap::ConstraintEvaluator::function_clauses ( )

Does the current constraint expression contain function clauses.

This method does not evaluate the clauses, it provides information to the evaluator regarding how to evaluate the clause.

Note: Added for libdap 3.11

Returns: True if the current constraint contains function clauses, otherwise returns False

Definition at line 226 of file ConstraintEvaluator.cc.

◆ functional_expression()

bool libdap::ConstraintEvaluator::functional_expression ( )

Does the current constraint expression return a BaseType pointer? This method does not evaluate the clause, it provides information to the evaluator regarding how to evaluate the clause.

Returns: True if the clause is a function that returns a BaseType* and false otherwise

Deprecated:

Definition at line 191 of file ConstraintEvaluator.cc.

◆ parse_constraint()

void libdap::ConstraintEvaluator::parse_constraint	(	const std::string &	constraint,
		DDS &	dds
	)

Parse the constraint expression given the current DDS.

Evaluate the constraint expression; return the value of the expression. As a side effect, mark the DDS so that BaseType's mfuncs can be used to correctly read the variable's value and send it to the client.

Parameters

constraint	A string containing the constraint expression.
dds	The DDS that provides the environment within which the constraint is evaluated.

Exceptions

Throws Error if the constraint does not parse.

Definition at line 363 of file ConstraintEvaluator.cc.

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

Public Types

Public Member Functions

Friends

Detailed Description

Member Function Documentation

◆ append_clause() [1/3]

◆ append_clause() [2/3]

◆ append_clause() [3/3]

◆ append_constant()

◆ boolean_expression()

◆ clause_begin()

◆ clause_end()

◆ clause_value()

◆ eval_function()

◆ eval_function_clauses() [1/2]

◆ eval_function_clauses() [2/2]

◆ eval_selection()

◆ find_function() [1/3]

◆ find_function() [2/3]

◆ find_function() [3/3]

◆ function_clauses()

◆ functional_expression()

◆ parse_constraint()