net.sf.saxon.expr
Class ArithmeticExpression10

java.lang.Object
  net.sf.saxon.expr.Expression
      net.sf.saxon.expr.BinaryExpression
          net.sf.saxon.expr.ArithmeticExpression10

All Implemented Interfaces:

Serializable, SourceLocator, EvaluableItem, SequenceIterable, InstructionInfoProvider

public class ArithmeticExpression10
extends BinaryExpression

Arithmetic Expression: an expression using one of the operators plus, minus, multiply, div, idiv, mod, in backwards compatibility mode: see ArithmeticExpression for the non-backwards compatible case.

See Also:

Serialized Form

Field Summary

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

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

ArithmeticExpression10(Expression p0, int operator, Expression p1)
Create an arithmetic expression to be evaluated in XPath 1.0 mode

Method Summary

Expression	copy() Copy an expression.
Item	evaluateItem(XPathContext context) Evaluate the expression.
ItemType	getItemType(TypeHierarchy th) Determine the data type of the expression, if this is known statically
boolean	isBackwardsCompatible() Determine whether the expression is to be evaluated in backwards-compatible mode
Expression	typeCheck(ExpressionVisitor visitor, ItemType contextItemType) Type-check the expression statically.

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

computeCardinality, computeSpecialProperties, equals, explain, getOperands, getOperator, hashCode, iterateSubExpressions, optimize, promote, replaceSubExpression, setFlattened, simplify, toString

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

addToPathMap, adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, effectiveBooleanValue, evaluateAsString, explain, findParentOf, getCardinality, getColumnNumber, getContainer, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, iterate, iterateEvents, markTailFunctionCalls, process, setContainer, setFiltered, setLocationId, staticTypeCheck, suppressValidation

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ArithmeticExpression10

public ArithmeticExpression10(Expression p0,
                              int operator,
                              Expression p1)

Create an arithmetic expression to be evaluated in XPath 1.0 mode

Parameters:

p0 - the first operand

operator - the operator, for example Token.PLUS

p1 - the second operand

Method Detail

isBackwardsCompatible

public boolean isBackwardsCompatible()

Determine whether the expression is to be evaluated in backwards-compatible mode

Returns:

true, always

typeCheck

public Expression typeCheck(ExpressionVisitor visitor,
                            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.

Overrides:

typeCheck in class BinaryExpression

Parameters:

visitor - an expression visitor

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:

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

getItemType

public ItemType getItemType(TypeHierarchy th)

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

Specified by:

getItemType in class Expression

Parameters:

th - the type hierarchy cache

Returns:

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

copy

public Expression copy()

Copy an expression. This makes a deep copy.

Specified by:

copy in class Expression

Returns:

the copy of the original expression

evaluateItem

public Item evaluateItem(XPathContext context)
                  throws XPathException

Evaluate the expression.

Specified by:

evaluateItem in interface EvaluableItem

Overrides:

evaluateItem in class Expression

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