Package net.sf.saxon.expr

Class ArithmeticExpression

java.lang.Object

net.sf.saxon.expr.ComputedExpression

net.sf.saxon.expr.BinaryExpression

net.sf.saxon.expr.ArithmeticExpression

All Implemented Interfaces:

java.io.Serializable, javax.xml.transform.SourceLocator, Container, Expression, InstructionInfoProvider

Direct Known Subclasses:

ArithmeticExpression.DateAndDuration, ArithmeticExpression.DateDifference, ArithmeticExpression.DurationAddition, ArithmeticExpression.DurationDivision, ArithmeticExpression.DurationMultiplication, ArithmeticExpression.NumericArithmetic

public class ArithmeticExpression
extends BinaryExpression

Arithmetic Expression: an expression using one of the operators plus, minus, multiply, div, idiv, mod.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ArithmeticExpression.DateAndDuration	Inner class to handle addition or subtraction of a Date (or Time, or DateTime) and a Duration
static class	ArithmeticExpression.DateDifference	Inner class to handle subtraction of a Date (or Time, or DateTime) from another, to return a Duration
static class	ArithmeticExpression.DurationAddition	Inner class to handle addition and subtraction of two durations
static class	ArithmeticExpression.DurationDivision	Inner class to handle division of two durations to give a number
static class	ArithmeticExpression.DurationMultiplication	Inner class to handle multiplication (or division) of a duration by a number
static class	ArithmeticExpression.NumericArithmetic	Inner class to handle numeric arithmetic expressions

Field Summary

Fields inherited from class net.sf.saxon.expr.BinaryExpression

operand0, operand1, operator

Fields inherited from class net.sf.saxon.expr.ComputedExpression

locationId, staticProperties

Fields inherited from interface net.sf.saxon.expr.Expression

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

Constructors

Constructor	Description
ArithmeticExpression(Expression p1, int operator, Expression p2)

Method Summary

Modifier and Type	Method	Description
Item	evaluateItem(XPathContext context)	Evaluate the expression.
ItemType	getItemType(TypeHierarchy th)	Determine the data type of the expression, if this is known statically
Expression	typeCheck(StaticContext env, ItemType contextItemType)	Type-check the expression statically.

Methods inherited from class net.sf.saxon.expr.BinaryExpression

computeCardinality, computeSpecialProperties, display, displayOperator, equals, getOperands, getOperator, hashCode, isAssociative, isCommutative, isInverse, iterateSubExpressions, optimize, promote, replaceSubExpression, simplify

Methods inherited from class net.sf.saxon.expr.ComputedExpression

adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, iterate, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, suppressValidation, typeError

Methods inherited from class java.lang.Object

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

Constructor Detail

ArithmeticExpression

public ArithmeticExpression(Expression p1,
                            int operator,
                            Expression p2)

Method Detail

typeCheck

public Expression typeCheck(StaticContext env,
                            ItemType contextItemType)
                     throws XPathException

Type-check the expression statically. We try to work out which particular arithmetic function to use if the types of operands are known an compile time.

Specified by:

typeCheck in interface Expression

Overrides:

typeCheck in class BinaryExpression

Parameters:

env - the static context of the expression

contextItemType - the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set to Type.ITEM_TYPE

Returns:

the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations

Throws:

StaticError - if an error is discovered during this phase (typically a type error)

XPathException

getItemType

public ItemType getItemType(TypeHierarchy th)

Determine the data type of the expression, if this is known statically

Parameters:

th -

Returns:

a value such as Type.STRING, Type.BOOLEAN, Type.NUMBER, Type.NODE, or Type.ITEM (meaning not known at compile time)

evaluateItem

public Item evaluateItem(XPathContext context)
                  throws XPathException

Evaluate the expression. We only take this path if the type could not be determined statically.

Specified by:

evaluateItem in interface Expression

Overrides:

evaluateItem in class ComputedExpression

Parameters:

context - The context in which the expression is to be evaluated

Returns:

the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence

Throws:

XPathException - if any dynamic error occurs evaluating the expression