ELAM::Engine Class Reference

The calculation engine of . More...

#include <elamengine.h>

Inheritance diagram for ELAM::Engine:

List of all members.

Public Types
enum	PriorityMatch { IgnoreMismatch = 0, OverridePrio = 1, FailIfMismatch = 2 }
	Matching mode for priority when overwriting an operator, see binaryOperator. More...
Public Slots
virtual QVariant	getValue (QString) const
	returns the value of the named variable or constant (default uses getVariable/getConstant)
virtual QVariant	getVariable (QString) const
	returns the value of the named variable (does not return constants)
virtual QVariant	getConstant (QString) const
	returns the value of the named constant (does not return variables)
virtual bool	setVariable (QString, QVariant)
	sets a variable
virtual bool	setConstant (QString, QVariant)
	sets a constant
virtual void	removeVariable (QString)
	deletes a variable (does not affect constants, does nothing if the variable does not exist)
virtual void	removeConstant (QString)
	deletes a constant (does not affect variables, does nothing if the constant does not exist)
virtual void	removeValue (QString)
	deletes a variable or constant (default uses removeVariable and removeConstant)
bool	setFunction (QString, Function)
	Sets a new function for a specific function name.
void	removeFunction (QString)
	removes a function
int	setLiteralParser (LiteralParser parser, QString startchars, int prio=50)
	sets the parser routine for a literal value
void	removeLiteralParser (int parserid)
	removes a parser function
void	setBinaryOperatorPrio (QString name, int prio)
	sets/overrides the priority of an operator, creating the operator if it does not exist yet
void	registerType (int typeId)
	registers a type as primary, this means it is not cast into another type when encountered
void	setAutoCast (int target, QList< int >origin, TypeCast castfunc, int prio=50)
	Registers an automatic cast function.
Expression	expression (QString)
	simply parses an expression string into an object
Expression	expression (QList< Token >)
	simply parses an expression string into an object
QList< Token >	tokenize (QString)
	simply parses an expression string into a list of tokens
QVariant	evaluate (QString)
	parses and evaluates an expression string into a final value
QVariant	evaluate (Expression)
	evaluates a parsed expression into a final value
CharacterClassSettings	characterClasses ()
	gives access to the character classes settings
Public Member Functions
	Engine (QObject *parent=0)
	instantiates an engine object
virtual Q_INVOKABLE bool	hasVariable (QString) const
	true if the named variable exists in this engine
virtual Q_INVOKABLE bool	hasConstant (QString) const
	true if the named constant exists in this engine
virtual Q_INVOKABLE bool	hasValue (QString) const
	true if a variable or constant of that name exists in this engine (default calls hasVariable() || hasConstant() )
Q_INVOKABLE bool	hasFunction (QString) const
	returns true if the named function exists
Q_INVOKABLE Function	getFunction (QString) const
	returns the pointer to the function
Q_INVOKABLE bool	hasUnaryOperator (QString name) const
	returns true if there is an unaryOperator with this name
Q_INVOKABLE bool	hasBinaryOperator (QString name) const
	returns true if there is an binaryOperator with this name
Q_INVOKABLE UnaryOperator	unaryOperator (QString name)
	returns an existing or new unary operator object
Q_INVOKABLE BinaryOperator	binaryOperator (QString name, int prio=1, PriorityMatch match=IgnoreMismatch)
	returns an existing or new binary operator object
Q_INVOKABLE int	binaryOperatorPrio (QString name)
	returns the priority of the operator, or -1 if the operator does not exist
Q_INVOKABLE bool	isAssignment (QString name) const
	returns true if the name represents an assignment operator
Q_INVOKABLE QVariant	autoCast (const QVariant &) const
	performs automatic casting
virtual Q_INVOKABLE QStringList	variableNames () const
	returns the names of all currently existing variables
virtual Q_INVOKABLE QStringList	constantNames () const
	returns the names of all currently existing constants
Q_INVOKABLE QStringList	functionNames () const
	returns the names of all currently existing functions
Q_INVOKABLE QStringList	binaryOperatorNames () const
	returns the names of all currently existing binary operators
Q_INVOKABLE QStringList	unaryOperatorNames () const
	returns the names of all currently existing unary operators
Static Public Member Functions
static void	configureReflection (Engine &)
	register reflection functions

---

Detailed Description

The calculation engine of .

Instances of this class can be configured to represent a specific system of functions and operators.

Methods of this class are used to evaluate expressions into final values.

---

Member Enumeration Documentation

enum ELAM::Engine::PriorityMatch

Matching mode for priority when overwriting an operator, see binaryOperator.

The matching mode has no effect if the operator is new or the priorities match. In those cases binaryOperator always returns the operator object corresponding to the given name for this engine.

The matching mode changes behavior if the operator exists and its priority is different from the one given in the call.

Enumerator:

IgnoreMismatch	if the operator is new: use the given priority, otherwise leave priority as is ignoring the one given in the call, this is the default
OverridePrio	override the priority of the existing operator, using the priority given in the call
FailIfMismatch	returns a dummy operator making it impossible to overwrite the existing operator

---

Constructor & Destructor Documentation

ELAM::Engine::Engine

(

QObject *

parent = 0

)

[explicit]

instantiates an engine object

---

Member Function Documentation

Q_INVOKABLE QVariant ELAM::Engine::autoCast

(

const QVariant &

)

const

performs automatic casting

Returns:

the casted value or the original value if it is of a primary type or if there is no known cast for it

Q_INVOKABLE BinaryOperator ELAM::Engine::binaryOperator	(	QString	name,
		int	prio = 1,
		PriorityMatch	match = IgnoreMismatch
	)

returns an existing or new binary operator object

Parameters:

	name	the name token of the operator, if the name is not a valid operator it cannot be called from this engine until character classes change
	prio	the priority that should be set for the operator
	match	how to behave if the operator already exists and priorities do not match, see PriorityMatch

Returns:

a reference to the operator, or to a dummy operator if priority matching failed

Q_INVOKABLE QStringList ELAM::Engine::binaryOperatorNames

(

)

const

returns the names of all currently existing binary operators

Q_INVOKABLE int ELAM::Engine::binaryOperatorPrio

(

QString

name

)

returns the priority of the operator, or -1 if the operator does not exist

CharacterClassSettings ELAM::Engine::characterClasses

(

)

[slot]

gives access to the character classes settings

static void ELAM::Engine::configureReflection

(

Engine &

)

[static]

register reflection functions

virtual Q_INVOKABLE QStringList ELAM::Engine::constantNames

(

)

const [virtual]

returns the names of all currently existing constants

QVariant ELAM::Engine::evaluate

(

QString

)

[slot]

parses and evaluates an expression string into a final value

QVariant ELAM::Engine::evaluate

(

Expression

)

[slot]

evaluates a parsed expression into a final value

Expression ELAM::Engine::expression

(

QString

)

[slot]

simply parses an expression string into an object

Expression ELAM::Engine::expression

(

QList< Token >

)

[slot]

simply parses an expression string into an object

Q_INVOKABLE QStringList ELAM::Engine::functionNames

(

)

const

returns the names of all currently existing functions

virtual QVariant ELAM::Engine::getConstant

(

QString

)

const [virtual, slot]

returns the value of the named constant (does not return variables)

Q_INVOKABLE Function ELAM::Engine::getFunction

(

QString

)

const

returns the pointer to the function

virtual QVariant ELAM::Engine::getValue

(

QString

)

const [virtual, slot]

returns the value of the named variable or constant (default uses getVariable/getConstant)

virtual QVariant ELAM::Engine::getVariable

(

QString

)

const [virtual, slot]

returns the value of the named variable (does not return constants)

Q_INVOKABLE bool ELAM::Engine::hasBinaryOperator

(

QString

name

)

const

returns true if there is an binaryOperator with this name

virtual Q_INVOKABLE bool ELAM::Engine::hasConstant

(

QString

)

const [virtual]

true if the named constant exists in this engine

Q_INVOKABLE bool ELAM::Engine::hasFunction

(

QString

)

const

returns true if the named function exists

Q_INVOKABLE bool ELAM::Engine::hasUnaryOperator

(

QString

name

)

const

returns true if there is an unaryOperator with this name

virtual Q_INVOKABLE bool ELAM::Engine::hasValue

(

QString

)

const [virtual]

true if a variable or constant of that name exists in this engine (default calls hasVariable() || hasConstant() )

virtual Q_INVOKABLE bool ELAM::Engine::hasVariable

(

QString

)

const [virtual]

true if the named variable exists in this engine

Q_INVOKABLE bool ELAM::Engine::isAssignment

(

QString

name

)

const

returns true if the name represents an assignment operator

void ELAM::Engine::registerType

(

int

typeId

)

[slot]

registers a type as primary, this means it is not cast into another type when encountered

Parameters:

typeId

the QVariant ID of the type to register

virtual void ELAM::Engine::removeConstant

(

QString

)

[virtual, slot]

deletes a constant (does not affect variables, does nothing if the constant does not exist)

void ELAM::Engine::removeFunction

(

QString

)

[slot]

removes a function

void ELAM::Engine::removeLiteralParser

(

int

parserid

)

[slot]

removes a parser function

virtual void ELAM::Engine::removeValue

(

QString

)

[virtual, slot]

deletes a variable or constant (default uses removeVariable and removeConstant)

virtual void ELAM::Engine::removeVariable

(

QString

)

[virtual, slot]

deletes a variable (does not affect constants, does nothing if the variable does not exist)

void ELAM::Engine::setAutoCast	(	int	target,
		QList< int >	origin,
		TypeCast	castfunc,
		int	prio = 50
	)			[slot]

Registers an automatic cast function.

Automatic cast functions must succeed in converting, if the result is uncertain (e.g. as in converting a string to a number) use an explicit function.

Parameters:

	target	the target of the cast function, the target is automatically registered as primary type (see registerType)
	origin	type IDs that are automatically converted using this function, origins that are also primary types are ignored
	castfunc	the function that converts these types
	prio	the priority of the cast, if a cast function for the same origin, but a higher priority exists the one with the higher priority is used; the priority must be a positive value

void ELAM::Engine::setBinaryOperatorPrio	(	QString	name,
		int	prio
	)			[slot]

sets/overrides the priority of an operator, creating the operator if it does not exist yet

virtual bool ELAM::Engine::setConstant	(	QString	,
		QVariant
	)			[virtual, slot]

sets a constant

Returns:

true on success or false if:

• the name is not valid
• a function of that name exists

Constants overwrite variables - if a variable of the same name exists, it is transparently deleted before the constant is created.

bool ELAM::Engine::setFunction	(	QString	,
		Function
	)			[slot]

Sets a new function for a specific function name.

If there already is a function of that name it is overridden.

Returns:

true on success or false if:

• the name is not syntactically valid
• the function is null
• a constant or variable of the same name exists already

int ELAM::Engine::setLiteralParser	(	LiteralParser	parser,
		QString	startchars,
		int	prio = 50
	)			[slot]

sets the parser routine for a literal value

Parameters:

	parser	pointer to the parser routine
	startchars	characters that the literal can start with, at least some of those characters must be part of the literalStart class, the ones which are not part of it will be ignored when recognizing a literal - if none are part of the class the literal cannot be used until the class changes
	prio	a value between 0 and 100, parsers with higher values are preferred over those with lower values if they share a start character

Returns:

>0 if the parser is registered successfully, or 0 if:

• the parser is null
• the start characters are empty
• the priority is outside the allowed range (0<=prio<=100)

A return value >0 can be used as an ID to remove the parser again with removeLiteralParser(int) .

If a parser function is registered a second time the new registration overwrites the old registration.

virtual bool ELAM::Engine::setVariable	(	QString	,
		QVariant
	)			[virtual, slot]

sets a variable

Returns:

true on success or false if:

• the name is not valid
• a function or constant of that name already exists

QList<Token> ELAM::Engine::tokenize

(

QString

)

[slot]

simply parses an expression string into a list of tokens

Q_INVOKABLE UnaryOperator ELAM::Engine::unaryOperator

(

QString

name

)

returns an existing or new unary operator object

Parameters:

name

the name token of the operator, if the name is not a valid operator it cannot be called from this engine until character classes change

Q_INVOKABLE QStringList ELAM::Engine::unaryOperatorNames

(

)

const

returns the names of all currently existing unary operators

virtual Q_INVOKABLE QStringList ELAM::Engine::variableNames

(

)

const [virtual]

returns the names of all currently existing variables

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The documentation for this class was generated from the following file:

• elamengine.h