Package freemarker.core

Class ArithmeticEngine

java.lang.Object

freemarker.core.ArithmeticEngine

Direct Known Subclasses:

ArithmeticEngine.BigDecimalEngine, ArithmeticEngine.ConservativeEngine

public abstract class ArithmeticEngine
extends Object

Used for implementing the arithmetic operations and number comparisons in the template language. The concrete implementation is plugged into the configuration with the arithmetical_engine setting. (See Configurable.setArithmeticEngine(ArithmeticEngine).)

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ArithmeticEngine.BigDecimalEngine	This is the default arithmetic engine in FreeMarker.
static class	ArithmeticEngine.ConservativeEngine	An arithmetic engine that conservatively widens the operation arguments to extent that they can hold the result of the operation.

Field Summary

Fields

Modifier and Type	Field	Description
static ArithmeticEngine.BigDecimalEngine	BIGDECIMAL_ENGINE	Arithmetic engine that converts all numbers to BigDecimal and then operates on them, and also keeps the result as a BigDecimal.
static ArithmeticEngine.ConservativeEngine	CONSERVATIVE_ENGINE	Arithmetic engine that uses (more-or-less) the widening conversions of Java language to determine the type of result of operation, instead of converting everything to BigDecimal up front.
protected int	maxScale
protected int	minScale
protected int	roundingPolicy

Constructor Summary

Constructors

Constructor	Description
ArithmeticEngine()

Method Summary

Modifier and Type	Method	Description
abstract Number	add(Number first, Number second)
abstract int	compareNumbers(Number first, Number second)
abstract Number	divide(Number first, Number second)
abstract Number	modulus(Number first, Number second)
abstract Number	multiply(Number first, Number second)
void	setMaxScale(int maxScale)	Sets the maximal scale to use when multiplying BigDecimal numbers.
void	setMinScale(int minScale)	Sets the minimal scale to use when dividing BigDecimal numbers.
void	setRoundingPolicy(int roundingPolicy)
abstract Number	subtract(Number first, Number second)
abstract Number	toNumber(String s)	Should be able to parse all FTL numerical literals, Java Double toString results, and XML Schema numbers.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

BIGDECIMAL_ENGINE

public static final ArithmeticEngine.BigDecimalEngine BIGDECIMAL_ENGINE

Arithmetic engine that converts all numbers to BigDecimal and then operates on them, and also keeps the result as a BigDecimal. This is FreeMarker's default arithmetic engine.

CONSERVATIVE_ENGINE

public static final ArithmeticEngine.ConservativeEngine CONSERVATIVE_ENGINE

Arithmetic engine that uses (more-or-less) the widening conversions of Java language to determine the type of result of operation, instead of converting everything to BigDecimal up front.

minScale

protected int minScale

maxScale

protected int maxScale

roundingPolicy

protected int roundingPolicy

Constructor Details

ArithmeticEngine

public ArithmeticEngine()

Method Details

compareNumbers

public abstract int compareNumbers(Number first,
 Number second)
                            throws TemplateException

Throws:

TemplateException

add

public abstract Number add(Number first,
 Number second)
                    throws TemplateException

Throws:

TemplateException

subtract

public abstract Number subtract(Number first,
 Number second)
                         throws TemplateException

Throws:

TemplateException

multiply

public abstract Number multiply(Number first,
 Number second)
                         throws TemplateException

Throws:

TemplateException

divide

public abstract Number divide(Number first,
 Number second)
                       throws TemplateException

Throws:

TemplateException

modulus

public abstract Number modulus(Number first,
 Number second)
                        throws TemplateException

Throws:

TemplateException

toNumber

public abstract Number toNumber(String s)

Should be able to parse all FTL numerical literals, Java Double toString results, and XML Schema numbers. This means these should be parsed successfully, except if the arithmetical engine couldn't support the resulting value anyway (such as NaN, infinite, even non-integers): -123.45, 1.5e3, 1.5E3, 0005, +0, -0, NaN, INF, -INF, Infinity, -Infinity.

setMinScale

public void setMinScale(int minScale)

Sets the minimal scale to use when dividing BigDecimal numbers. Default value is 12.

setMaxScale

public void setMaxScale(int maxScale)

Sets the maximal scale to use when multiplying BigDecimal numbers. Default value is 100.

setRoundingPolicy

public void setRoundingPolicy(int roundingPolicy)