QtxEvalExpr Class Reference

String expression evaluator.

#include <QtxEvalExpr.h>

Public Types
enum	Error {   OK, OperandsNotMatch, InvalidResult, InvalidOperation,   OperationsNull, InvalidToken, CloseExpected, ExcessClose,   BracketsNotMatch, StackUnderflow, ExcessData }
	Parsing error type. More...
Public Member Functions
	QtxEvalExpr (const QString &=QString())
	Constructor.
	QtxEvalExpr (const bool, const QString &=QString())
	Constructor.
	~QtxEvalExpr ()
	Destructor.
QVariant	calculate (const QString &=QString())
	Evaluate the expression.
QString	expression () const
	Get the expression.
void	setExpression (const QString &)
	Set the expression.
Error	error () const
	Get the code of latest parsing error.
QtxEvalParser *	parser () const
	Get the expression parser.
bool	autoDeleteOperationSets () const
	Get the 'auto-delete operations' flag value.
void	setAutoDeleteOperationSets (const bool)
	Set the 'auto-delete operations' flag value.
QList< QtxEvalSet * >	operationSets () const
	Get current set of operations.
QtxEvalSet *	operationSet (const QString &) const
	Get the operation by name.
void	removeOperationSet (QtxEvalSet *)
	Remove the operation.
void	insertOperationSet (QtxEvalSet *, const int=-1)
	Install the operation.
Private Member Functions
void	intialize (const bool, const QString &)
	Initialize the evaluator.
Private Attributes
QString	myExpr
QtxEvalParser *	myParser

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Member Enumeration Documentation

enum QtxEvalExpr::Error

Enumerator:

OK	No errors found.
OperandsNotMatch	Types of arguments are invalid for this operation.
InvalidResult	Operation cannot find result (for example, division by zero)
InvalidOperation	Unknown operation.
OperationsNull	Internal operations pointer of parser is null.
InvalidToken	Invalid token (neither operation, nor parameter of value)
CloseExpected	Closing bracket is expected.
ExcessClose	Extra closing bracket is found.
BracketsNotMatch	Opening and closing brackets are of different type, e.g. [)
StackUnderflow	There are no arguments in the stack for the operation.
ExcessData	The parsing is finished, but there are more then one value in the stack.

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Constructor & Destructor Documentation

QtxEvalExpr::QtxEvalExpr

(

const QString &

expr = QString()

)

The evaluator is initalized by standard operations. Use another constructor with parameter stdSets = false to avoid initialization of evaluator with standard operations.

Parameters:

expr	expression to be evaluated

References intialize().

QtxEvalExpr::QtxEvalExpr	(	const bool	stdSets,
		const QString &	expr = QString()
	)

Parameters:

stdSets	if true, the evaluator is initalized by standard operations
expr	expression to be evaluated

References intialize().

QtxEvalExpr::~QtxEvalExpr

(

)

References myParser.

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Member Function Documentation

QVariant QtxEvalExpr::calculate

(

const QString &

expr = QString()

)

Parameters:

expr	expression to be evaluated

Returns:

result of the evaluation

References QtxEvalParser.calculate(), myParser, and setExpression().

QString QtxEvalExpr::expression

(

)

const

Returns:

expression string

References myExpr.

void QtxEvalExpr::setExpression

(

const QString &

expr

)

Parameters:

expr	expression string

References expression(), myExpr, myParser, and QtxEvalParser.setExpression().

QtxEvalExpr::Error QtxEvalExpr::error

(

)

const

Returns:

the code of the last error

References QtxEvalParser.error(), and myParser.

QtxEvalParser * QtxEvalExpr::parser

(

)

const

Returns:

expression parser

References myParser.

bool QtxEvalExpr::autoDeleteOperationSets

(

)

const

Returns:

true if all operations shoud be automatically deleted when the evaluator is destroyed

See also:

setAutoDeleteOperationSets()

References QtxEvalParser.autoDeleteOperationSets(), and myParser.

void QtxEvalExpr::setAutoDeleteOperationSets

(

const bool

on

)

Parameters:

on	if true, all operations shoud be automatically deleted when the evaluator is destroyed

See also:

autoDeleteOperationSets()

References myParser, and QtxEvalParser.setAutoDeleteOperationSets().

QList< QtxEvalSet * > QtxEvalExpr::operationSets

(

)

const

Returns:

operations set

See also:

insertOperationSet(), removeOperationSet(), operationSet()

References myParser, and QtxEvalParser.operationSets().

QtxEvalSet * QtxEvalExpr::operationSet

(

const QString &

name

)

const

Parameters:

name	operation name

Returns:

operation of 0 if not found

See also:

operationSets(), insertOperationSet(), removeOperationSet()

References myParser, and QtxEvalParser.operationSet().

void QtxEvalExpr::removeOperationSet

(

QtxEvalSet *

set

)

Parameters:

operation

to be removed

See also:

operationSets(), insertOperationSet(), operationSet()

References myParser, and QtxEvalParser.removeOperationSet().

void QtxEvalExpr::insertOperationSet	(	QtxEvalSet *	set,
		const int	idx = -1
	)

Parameters:

operation	to be added
idx	index in the list at which the operation shoud be inserted

See also:

operationSets(), removeOperationSet(), operationSet()

References QtxEvalParser.insertOperationSet(), and myParser.

void QtxEvalExpr::intialize	(	const bool	stdSets,
		const QString &	expr
	)		[private]

Parameters:

stdSets	if true, the evaluator is initalized by standard operations
expr	expression to be evaluated

References QtxEvalParser.insertOperationSet(), myParser, QtxEvalParser.setAutoDeleteOperationSets(), and setExpression().

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Field Documentation

QString QtxEvalExpr.myExpr [private]

QtxEvalParser* QtxEvalExpr.myParser [private]