OrCondExpression Class Reference

Represents XQuery disjunction or of two conditions. More...

#include <orcondexpression.h>

Inheritance diagram for OrCondExpression:

Collaboration diagram for OrCondExpression:

List of all members.

Public Member Functions

OrCondExpression (CondExpression *_left, CondExpression *_right)

Constructor.

virtual ~OrCondExpression ()

virtual void scopeCheck (vector< unsigned > &def_vars, vector< unsigned > &introduced_vars, vector< unsigned > &violating_vars)

virtual void replaceVarId (unsigned old_id, unsigned new_id)

virtual void extractFSAMap (FSAMap *fsamap, unsigned parent_var)

virtual void extractParVarMap (ParVarMap *parvarmap)

virtual void extractDependencies (vector< DependencySet * > *depset)

virtual Expression * placeSignOffs (vector< SignOffExpression * > &signoffs)

virtual void rewriteEmptyFuncts ()

virtual void rewriteVarstepCondExps ()

virtual void rewriteAggregateFuncts ()

virtual void print (OutputStream &dos) const

virtual void init (BufferNode *root)

virtual void eval (OutputStream &eos, Environment *env, unsigned modus)

virtual bool evalCond (OutputStream &eos, Environment *env, unsigned modus)

Private Attributes

CondExpression * left

The entered CondExpression on the left hand side of disjunction or.

CondExpression * right

The entered CondExpression on the right hand side of disjunction or.

Detailed Description

Represents XQuery disjunction or of two conditions.

Represents XQuery disjunction or of two conditions, which takes therefore two CondExpression, e.g. fn:false() or fn:true() or $x/bib/book != /bib//book or fn:count($x) < 3, as arguments and returns the or disjunction of both conditions, i.e. returns true if at least one CondExpression is true, false otherwise.

Author:: Michael Schmidt
Gunnar Jehl

Version:: 2.1

License:: Software License Agreement (BSD License)

Definition at line 52 of file orcondexpression.h.

Constructor & Destructor Documentation

OrCondExpression::OrCondExpression	(	CondExpression *	_left,
		CondExpression *	_right
	)

Constructor.

Constructor - creating object for two CondExpression.

Parameters:

`[in]`	_left	Pointer to a CondExpression object.
`[in]`	_right	Pointer to a CondExpression object.

Definition at line 37 of file orcondexpression.cpp.

OrCondExpression::~OrCondExpression ( ) [virtual]

Destructor.

Definition at line 41 of file orcondexpression.cpp.

References left, and right.

Member Function Documentation

void OrCondExpression::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.

Reimplemented from Expression.

Definition at line 123 of file orcondexpression.cpp.

References Expression::eval(), EVAL_SIGNOFF, left, and right.

bool OrCondExpression::evalCond	(	OutputStream &	eos,
		Environment *	env,
		unsigned	modus
	)			`[virtual]`

Evaluates the corresponding CondExpression.

Parameters:

`[in]`	eos	Pointer to a OutputStream object.
`[in]`	env	Pointer to a Environment object.
`[in]`	modus	Evaluation modus.

Return values:

bool true if the corresponding CondExpression is true, false otherwise.

Exceptions:

RuntimeException

If illegal evaluation mode (argument: unsigned modus).

Implements CondExpression.

Definition at line 140 of file orcondexpression.cpp.

References EVAL_SIGNOFF, CondExpression::evalCond(), left, and right.

void OrCondExpression::extractDependencies ( vector< DependencySet * > * depset ) [virtual]

Extracts the needed dependencies of a query.

Extracts the needed dependencies of a query, which are needed for constructing the ProjectionTree.

Parameters:

[in,out] depset Pointer to a vector containing Pointer to DependencySet objects.

Return values:

void

Reimplemented from Expression.

Definition at line 68 of file orcondexpression.cpp.

References Expression::extractDependencies(), left, and right.

void OrCondExpression::extractFSAMap	(	FSAMap *	fsamap,
		unsigned	parent_var
	)			`[virtual]`

Extracts the needed first straight ancestor (FSA) variables map.

Extracts the needed first straight ancestor (FSA) variables map, which is needed for correct insertion of SignOffExpression.

Parameters:

`[in,out]`	fsamap	Pointer to a FSAMap object.
`[in]`	parent_var	Parent variable.

Return values:

void

Reimplemented from Expression.

Definition at line 58 of file orcondexpression.cpp.

References Expression::extractFSAMap(), left, and right.

void OrCondExpression::extractParVarMap ( ParVarMap * parvarmap ) [virtual]

Extracts the needed parent variable (ParVar) map.

Extracts the needed parent variable (ParVar) map, which is needed for constructing the VariableTree.

Parameters:

[in,out] parvarmap Pointer to a ParVarMap object.

Return values:

void

Reimplemented from Expression.

Definition at line 63 of file orcondexpression.cpp.

References Expression::extractParVarMap(), left, and right.

void OrCondExpression::init ( BufferNode * root ) [virtual]

Initializes the query for evaluation.

Initializes the query for evaluation. Up to now only all required BufferIterator objects are created to speed up query evaluation.

Parameters:

[in] root Pointer to a BufferNode object.

Return values:

void

Reimplemented from Expression.

Definition at line 118 of file orcondexpression.cpp.

References Expression::init(), left, and right.

Expression * OrCondExpression::placeSignOffs ( vector< SignOffExpression * > & signoffs ) [virtual]

Places all signOff-statements in the corresponding query.

Places all signOff-statements in the corresponding query, which are needed for active garbage collection by removing Role from the BufferNode.

Parameters:

[in] signoffs Pointer to a vector containing Pointer to SignOffExpression objects.

Return values:

Expression*

Pointer to a Expression object (following expression in the corresponding query).

Reimplemented from Expression.

Definition at line 73 of file orcondexpression.cpp.

References left, Expression::placeSignOffs(), and right.

void OrCondExpression::print ( OutputStream & dos ) const [virtual]

Prints the expression.

Parameters:

[in] dos Pointer to a OutputStream object.

Return values:

void

Implements Expression.

Definition at line 96 of file orcondexpression.cpp.

References Expression::getType(), left, and right.

void OrCondExpression::replaceVarId	(	unsigned	old_id,
		unsigned	new_id
	)			`[virtual]`

Replaces all matching variable IDs by a new one.

Replaces all matching variable IDs by a new one, which is needed in case of calling method rewriteVarsteps().

Parameters:

`[in]`	old_id	Old variable ID.
`[in]`	new_id	New variable ID, which should be introduced instead.

Return values:

void

Reimplemented from Expression.

Definition at line 53 of file orcondexpression.cpp.

References left, Expression::replaceVarId(), and right.

void OrCondExpression::rewriteAggregateFuncts ( ) [virtual]

Rewrites all arguments of all aggregate functions into an equivalent for-clause (with return-clause).

Return values:

void

Reimplemented from Expression.

Definition at line 91 of file orcondexpression.cpp.

References left, Expression::rewriteAggregateFuncts(), and right.

void OrCondExpression::rewriteEmptyFuncts ( ) [virtual]

Rewrites all fn:empty XQuery functions into equivalent fn:not(fn:exists) XQuery functions.

Return values:

void

Reimplemented from Expression.

Definition at line 81 of file orcondexpression.cpp.

References left, Expression::rewriteEmptyFuncts(), and right.

void OrCondExpression::rewriteVarstepCondExps ( ) [virtual]

Rewrites all if($x) if-conditions into equivalent if(fn:not(fn:empty($x))) XQuery expressions.

Return values:

void

Reimplemented from Expression.

Definition at line 86 of file orcondexpression.cpp.

References left, Expression::rewriteVarstepCondExps(), and right.

void OrCondExpression::scopeCheck	(	vector< unsigned > &	def_vars,
		vector< unsigned > &	introduced_vars,
		vector< unsigned > &	violating_vars
	)			`[virtual]`

Returns if all used variables were previously (through a for-clause) defined or if a variable leaves their defined scope.

Parameters:

`[in]`	def_vars	Vector containing all previously defined variables.
`[in]`	introduced_vars	Vector containing all up to this expression defined variables.
`[in]`	violating_vars	Vector containing all variables which violates the scope condition.

Return values:

void

Reimplemented from Expression.

Definition at line 46 of file orcondexpression.cpp.

References left, right, and Expression::scopeCheck().

Member Data Documentation

CondExpression * OrCondExpression::left [private]

The entered CondExpression on the left hand side of disjunction or.

The entered CondExpression on the left hand side of disjunction or, which is the first argument of the constructor.

Definition at line 141 of file orcondexpression.h.

Referenced by eval(), evalCond(), extractDependencies(), extractFSAMap(), extractParVarMap(), init(), placeSignOffs(), print(), replaceVarId(), rewriteAggregateFuncts(), rewriteEmptyFuncts(), rewriteVarstepCondExps(), scopeCheck(), and ~OrCondExpression().

CondExpression * OrCondExpression::right [private]

The entered CondExpression on the right hand side of disjunction or.

The entered CondExpression on the right hand side of disjunction or, which is the second argument of the constructor.

Definition at line 148 of file orcondexpression.h.

Referenced by eval(), evalCond(), extractDependencies(), extractFSAMap(), extractParVarMap(), init(), placeSignOffs(), print(), replaceVarId(), rewriteAggregateFuncts(), rewriteEmptyFuncts(), rewriteVarstepCondExps(), scopeCheck(), and ~OrCondExpression().


Public Member Functions
	OrCondExpression (CondExpression _left, CondExpression _right)
	Constructor.
virtual	~OrCondExpression ()
virtual void	scopeCheck (vector< unsigned > &def_vars, vector< unsigned > &introduced_vars, vector< unsigned > &violating_vars)
virtual void	replaceVarId (unsigned old_id, unsigned new_id)
virtual void	extractFSAMap (FSAMap *fsamap, unsigned parent_var)
virtual void	extractParVarMap (ParVarMap *parvarmap)
virtual void	extractDependencies (vector< DependencySet * > *depset)
virtual Expression *	placeSignOffs (vector< SignOffExpression * > &signoffs)
virtual void	rewriteEmptyFuncts ()
virtual void	rewriteVarstepCondExps ()
virtual void	rewriteAggregateFuncts ()
virtual void	print (OutputStream &dos) const
virtual void	init (BufferNode *root)
virtual void	eval (OutputStream &eos, Environment *env, unsigned modus)
virtual bool	evalCond (OutputStream &eos, Environment *env, unsigned modus)
Private Attributes
CondExpression *	left
	The entered CondExpression on the left hand side of disjunction `or`.
CondExpression *	right
	The entered CondExpression on the right hand side of disjunction `or`.