net.sf.saxon.expr

Class QuantifiedExpression

java.lang.Object

net.sf.saxon.expr.ComputedExpression

net.sf.saxon.expr.Assignation

net.sf.saxon.expr.QuantifiedExpression

All Implemented Interfaces:

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

class QuantifiedExpression
extends Assignation

A QuantifiedExpression tests whether some/all items in a sequence satisfy some condition.

Field Summary

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

action, declaration, nameCode, sequence, slotNumber, variableName

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 and Description
QuantifiedExpression()

Method Summary

Modifier and Type	Method and Description
int	computeCardinality() Determine the static cardinality
int	computeSpecialProperties() Determine the special properties of this expression
void	display(int level, java.io.PrintStream out, Configuration config) Diagnostic print of expression structure
boolean	effectiveBooleanValue(XPathContext context) Get the result as a boolean
Item	evaluateItem(XPathContext context) Evaluate the expression to return a singleton value
ItemType	getItemType(TypeHierarchy th) Determine the data type of the items returned by the expression
Expression	optimize(Optimizer opt, StaticContext env, ItemType contextItemType) Perform optimisation of an expression and its subexpressions.
void	setOperator(int operator)
Expression	typeCheck(StaticContext env, ItemType contextItemType) Type-check the expression

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

evaluateVariable, extendBindingList, getAction, getLocalSlotNumber, getRequiredSlots, getSequence, getVariableDeclaration, getVariableFingerprint, getVariableName, getVariableNameCode, isAssignable, isGlobal, iterateSubExpressions, promote, promoteWhereClause, replaceSubExpression, setAction, setSequence, setSlotNumber, setVariableDeclaration, simplify, suppressValidation

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

adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, 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, typeError

Methods inherited from class java.lang.Object

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

Constructor Detail

QuantifiedExpression

QuantifiedExpression()

Method Detail

setOperator

public void setOperator(int operator)

computeCardinality

public int computeCardinality()

Determine the static cardinality

Specified by:

computeCardinality in class ComputedExpression

typeCheck

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

Type-check the expression

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

optimize

public Expression optimize(Optimizer opt,
                           StaticContext env,
                           ItemType contextItemType)
                    throws XPathException

Perform optimisation of an expression and its subexpressions.

This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.

Parameters:

opt - the optimizer in use. This provides access to supporting functions; it also allows different optimization strategies to be used in different circumstances.

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 if appropriate to optimize execution

Throws:

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

XPathException

computeSpecialProperties

public int computeSpecialProperties()

Determine the special properties of this expression

Overrides:

computeSpecialProperties in class ComputedExpression

Returns:

StaticProperty.NON_CREATIVE.

evaluateItem

public Item evaluateItem(XPathContext context)
                  throws XPathException

Evaluate the expression to return a singleton value

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

effectiveBooleanValue

public boolean effectiveBooleanValue(XPathContext context)
                              throws XPathException

Get the result as a boolean

Specified by:

effectiveBooleanValue in interface Expression

Overrides:

effectiveBooleanValue in class ComputedExpression

Parameters:

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

Returns:

the effective boolean value

Throws:

XPathException - if any dynamic error occurs evaluating the expression

getItemType

public ItemType getItemType(TypeHierarchy th)

Determine the data type of the items returned by the expression

Parameters:

th -

Returns:

Type.BOOLEAN

display

public void display(int level,
                    java.io.PrintStream out,
                    Configuration config)

Diagnostic print of expression structure

Parameters:

level - indentation level for this expression

out - Output destination