Expression::Scope Class Reference

When evaluating an Expression object, this class is used to resolve symbols and perform functions that the expression uses. More...

Inheritance diagram for Expression::Scope:

Classes
class	Visitor
	Used as a callback by the Scope::visitRelativeScope() method. More...

Public Member Functions
	Scope ()
virtual	~Scope ()
virtual String	getScopeUID () const
	Returns some kind of globally unique ID that identifies this scope.
virtual Expression	getSymbolValue (const String &symbol) const
	Returns the value of a symbol.
virtual double	evaluateFunction (const String &functionName, const double *parameters, int numParameters) const
	Executes a named function.
virtual void	visitRelativeScope (const String &scopeName, Visitor &visitor) const
	Creates a Scope object for a named scope, and then calls a visitor to do some kind of processing with this new scope.

Detailed Description

When evaluating an Expression object, this class is used to resolve symbols and perform functions that the expression uses.

Constructor & Destructor Documentation

Scope()

Expression::Scope::Scope

(

)

Referenced by Expression::Scope::Visitor::visit().

~Scope()

virtual Expression::Scope::~Scope ( )

virtual

Member Function Documentation

getScopeUID()

virtual String Expression::Scope::getScopeUID ( ) const

virtual

Returns some kind of globally unique ID that identifies this scope.

Reimplemented in RelativeCoordinatePositionerBase::ComponentScope.

getSymbolValue()

virtual Expression Expression::Scope::getSymbolValue ( const String & symbol ) const

virtual

Returns the value of a symbol.

If the symbol is unknown, this can throw an Expression::EvaluationError exception. The member value is set to the part of the symbol that followed the dot, if there is one, e.g. for "foo.bar", symbol = "foo" and member = "bar".

Exceptions

Expression::EvaluationError

Reimplemented in RelativeCoordinatePositionerBase::ComponentScope.

References Expression::Expression(), and Expression::symbol().

evaluateFunction()

virtual double Expression::Scope::evaluateFunction ( const String & functionName, const double * parameters, int numParameters ) const

virtual

Executes a named function.

If the function name is unknown, this can throw an Expression::EvaluationError exception.

Exceptions

Expression::EvaluationError

visitRelativeScope()

virtual void Expression::Scope::visitRelativeScope ( const String & scopeName, Visitor & visitor ) const

virtual

Creates a Scope object for a named scope, and then calls a visitor to do some kind of processing with this new scope.

If the name is valid, this method must create a suitable (temporary) Scope object to represent it, and must call the Visitor::visit() method with this new scope.

Reimplemented in RelativeCoordinatePositionerBase::ComponentScope.