opendap.servers

Class BoolFunctionClause

java.lang.Object

opendap.servers.AbstractClause

opendap.servers.BoolFunctionClause

All Implemented Interfaces:

Clause, TopLevelClause

public class BoolFunctionClause
extends AbstractClause
implements TopLevelClause

Represents a clause which invokes a function that returns a boolean value.

Author:

joew

See Also:

ClauseFactory

Field Summary

Fields

Modifier and Type	Field and Description
protected BoolFunction	function
protected boolean	value

Fields inherited from class opendap.servers.AbstractClause

children, constant, defined

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BoolFunctionClause(BoolFunction function, List children) Creates a new BoolFunctionClause.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	evaluate() Evaluates the clause, first calling evaluate() on any sub-clauses it contains.
BoolFunction	getFunction() Returns the server-side function invoked by this clause
boolean	getValue() Returns the current value of the clause.
void	printConstraint(PrintWriter os) Prints the original string representation of this clause.

Methods inherited from class opendap.servers.AbstractClause

getChildren, isConstant, isDefined

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface opendap.servers.Clause

getChildren, isConstant, isDefined

Field Detail

function

protected BoolFunction function

value

protected boolean value

Constructor Detail

BoolFunctionClause

protected BoolFunctionClause(BoolFunction function,
                  List children)
                      throws DAP2ServerSideException

Creates a new BoolFunctionClause.

Parameters:

function - The function invoked by the clause

children - A list of SubClauses, to be given as arguments to the function. If all the arguments are constant, the function clause will be flagged as constant, and evaluated immediatelyx.

Throws:

DAP2ServerSideException - Thrown if either 1) the function does not accept the arguments given, or 2) the clause is constant, and the attempt to evaluate it fails.

Method Detail

getValue

public boolean getValue()

Description copied from interface: TopLevelClause

Returns the current value of the clause. The value of non-constant Clauses is undefined until the evaluate() method has been called.

Specified by:

getValue in interface TopLevelClause

evaluate

public boolean evaluate()
                 throws DAP2ServerSideException

Description copied from interface: TopLevelClause

Evaluates the clause, first calling evaluate() on any sub-clauses it contains. Implementations of this method should flag the clause as "defined" if the evaluation is successful.

Specified by:

evaluate in interface TopLevelClause

Throws:

DAP2ServerSideException - Thrown if the evaluation fails for any reason.

getFunction

public BoolFunction getFunction()

Returns the server-side function invoked by this clause

printConstraint

public void printConstraint(PrintWriter os)

Prints the original string representation of this clause. For use in debugging.

Specified by:

printConstraint in interface Clause