AggregateFunctVarPopExpression Class Reference

Represents XQuery non-standard function fn:var_pop. More...

#include <aggregatefunctvarpopexpression.h>

Inheritance diagram for AggregateFunctVarPopExpression:

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Collaboration diagram for AggregateFunctVarPopExpression:

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List of all members.

Public Member Functions
	AggregateFunctVarPopExpression (VarExpression *_var)
	Constructor.
	AggregateFunctVarPopExpression (VarStepExpression *_varstep)
	Constructor.
virtual	~AggregateFunctVarPopExpression ()
virtual void	eval (OutputStream &eos, Environment *env, unsigned modus)
Private Member Functions
virtual long double	calculateValue (OutputStream &eos, Environment *env, unsigned modus, bool &empty_sequence)

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Detailed Description

Represents XQuery non-standard function fn:var_pop.

Represents XQuery non-standard function fn:var_pop, which takes either a VarExpression, e.g. fn:var_pop($x), or a VarStepExpression, e.g. fn:var_pop($x/bib/book) or fn:var_pop(/bib//book) respectively, as argument and returns the population variance of the sequence located through the entered VarExpression or the entered VarStepExpression respectively.

Author:

Michael Schmidt

Gunnar Jehl

Version:

2.1

License:

Software License Agreement (BSD License)

Definition at line 60 of file aggregatefunctvarpopexpression.h.

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Constructor & Destructor Documentation

AggregateFunctVarPopExpression::AggregateFunctVarPopExpression

(

VarExpression *

_var

)

Constructor.

Constructor - creating object for a VarExpression.

Parameters:

[in]

_var

Pointer to a VarExpression object.

Definition at line 37 of file aggregatefunctvarpopexpression.cpp.

AggregateFunctVarPopExpression::AggregateFunctVarPopExpression

(

VarStepExpression *

_varstep

)

Constructor.

Constructor - creating object for a VarStepExpression.

Parameters:

[in]

_varstep

Pointer to a VarStepExpression object.

Definition at line 41 of file aggregatefunctvarpopexpression.cpp.

AggregateFunctVarPopExpression::~AggregateFunctVarPopExpression

(

)

[virtual]

Destructor.

Definition at line 45 of file aggregatefunctvarpopexpression.cpp.

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Member Function Documentation

long double AggregateFunctVarPopExpression::calculateValue	(	OutputStream &	eos,
		Environment *	env,
		unsigned	modus,
		bool &	empty_sequence
	)			[private, virtual]

Result calculation of the corresponding aggregate function.

Result calculation of the corresponding aggregate function.

Parameters:

[in]	eos	Pointer to a OutputStream object.
[in]	env	Pointer to a Environment object.
[in]	modus	Evaluation modus.
[in]	empty_sequence	Indicator if aggreagte function is called on an empty sequence.

Return values:

long

double Result of the corresponding aggregate function.

Implements AggregateFunctExpression.

Definition at line 99 of file aggregatefunctvarpopexpression.cpp.

References AggregateFunctExpression::bit, BufferIterator::clear(), ForExpression::evalSignOffForBinding(), AggregateFunctExpression::forexp, MiscFunctions::getDivisionFrom(), VarExpression::getId(), BufferIterator::getNext(), Environment::getNodeBinding(), MiscFunctions::getNumericFromString(), MiscFunctions::getPowerFrom(), MiscFunctions::getRoundFrom(), MiscFunctions::getSummationFrom(), BufferIterator::init(), LOCK_CONTEXT_ALWAYS_CLEAR, READ_UP_TO_CLOSE_CONTEXT, AggregateFunctExpression::var, and AggregateFunctExpression::varstep.

Referenced by eval().

void AggregateFunctVarPopExpression::eval	(	OutputStream &	eos,
		Environment *	env,
		unsigned	modus
	)			[virtual]

Evaluates the expression in the given environment.

Evaluates the expression in the given environment. The evaluation takes place in the environment that is passed to this method. In addition, the parameter modus is one of the following: EVAL_QUERY, EVAL_QUERY_SILENT or EVAL_SIGNOFF (see also the corresponding defines for more information). This method implements the XQuery semantics for the standard expression types, but also the GCX specific extensions like signOff-statements.

Parameters:

[in]	eos	Pointer to a OutputStream object.
[in]	env	Pointer to an Environment object.
[in]	modus	The query evaluation mode.

Exceptions:

RuntimeException

If illegal evaluation mode.

Exceptions:

InvalidCastException

If it is not possible to cast all affected PCDATA values of an XML document to numeric values or some value calculation will cause an (internal) error.

Implements AggregateFunctExpression.

Definition at line 48 of file aggregatefunctvarpopexpression.cpp.

References calculateValue(), OperandExpression::cur_val, ForExpression::eval(), EVAL_QUERY, EVAL_QUERY_SILENT, EVAL_SIGNOFF, AggregateFunctExpression::forexp, MiscFunctions::getStringFromNumerical(), OUTPUT_VARPOP_ON_EMPTY_SEQUENCE, Value::setNumVal(), and Value::setStrVal().