Package com.saxonica.xsltextn.instruct

Class While

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.instruct.Instruction

com.saxonica.xsltextn.instruct.While

All Implemented Interfaces:

ExportAgent, Locatable, IdentityComparable, Traceable

public class While
extends Instruction

Handler for saxon:while elements in stylesheet.
The saxon:while element has a mandatory attribute test, a boolean expression. The content is output repeatedly so long as the test condition is true.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	While.WhileElaborator

Field Summary

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

EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, MAX_COST, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, UPDATE_METHOD, WATCH_METHOD

Constructor Summary

Constructors

Constructor	Description
While(Expression test, Expression action)

Method Summary

Modifier and Type	Method	Description
Expression	copy(RebindingMap rebindings)	Copy an expression.
void	export(ExpressionPresenter out)	Diagnostic print of expression structure.
Expression	getAction()
Expression	getActionExpression()	Get the action expression (the content of the for-each)
Elaborator	getElaborator()	Make an elaborator for this expression
int	getInstructionNameCode()	Get the name of this instruction for diagnostic and tracing purposes
ItemType	getItemType()	Get the item type of the items returned by evaluating this instruction
Expression	getTest()
boolean	mayCreateNewNodes()	Determine whether this instruction creates new nodes.
java.lang.Iterable<Operand>	operands()	Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression.
void	setAction(Expression action)
void	setTest(Expression test)

Methods inherited from class net.sf.saxon.expr.instruct.Instruction

alwaysCreatesNewNodes, assembleParams, assembleTunnelParams, computeCardinality, computeSpecialProperties, dynamicError, evaluateAsString, evaluateItem, getExpressionName, getImplementationMethod, getNetCost, getSourceLocator, isInstruction, isXSLT, iterate, process, someOperandCreatesNewNodes

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

addToPathMap, adoptChildExpression, allowExtractingCommonSubexpressions, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeHashCode, computeStaticProperties, dispatchTailCall, dynamicError, effectiveBooleanValue, equals, explain, getCardinality, getConfiguration, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getIntegerBounds, getIntrinsicDependencies, getLocalRetainedStaticContext, getLocation, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStaticUType, getStreamerName, getTracingTag, hasCompatibleStaticContext, hashCode, hasSpecialProperty, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isEqual, isIdentical, isLiftable, isMultiThreaded, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, makeElaborator, markTailFunctionCalls, operandList, operandSparseList, optimize, optimizeChildren, prepareForStreaming, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setFlattened, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, supportsLazyEvaluation, suppressValidation, toPattern, toShortString, toString, typeCheck, typeCheckChildren, typeError, unordered, verifyParentPointers

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sf.saxon.trace.Traceable

gatherProperties

Constructor Detail

While

public While(Expression test,
             Expression action)

Method Detail

getTest

public Expression getTest()

setTest

public void setTest(Expression test)

getAction

public Expression getAction()

setAction

public void setAction(Expression action)

operands

public java.lang.Iterable<Operand> operands()

Description copied from class: Expression

Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression.

If the expression is a Callable, then it is required that the order of the operands returned by this function is the same as the order of arguments supplied to the corresponding call() method.

Specified by:

operands in class Instruction

Returns:

an iterator containing the sub-expressions of this expression

getInstructionNameCode

public int getInstructionNameCode()

Get the name of this instruction for diagnostic and tracing purposes

Overrides:

getInstructionNameCode in class Instruction

Returns:

the string "saxon:while"

getActionExpression

public Expression getActionExpression()

Get the action expression (the content of the for-each)

copy

public Expression copy(RebindingMap rebindings)

Copy an expression. This makes a deep copy.

Specified by:

copy in class Expression

Parameters:

rebindings - variables that need to be re-bound

Returns:

the copy of the original expression

getItemType

public ItemType getItemType()

Get the item type of the items returned by evaluating this instruction

Overrides:

getItemType in class Instruction

Returns:

the static item type of the instruction

mayCreateNewNodes

public final boolean mayCreateNewNodes()

Determine whether this instruction creates new nodes. This implementation returns true if the "action" creates new nodes. (Nodes created by the condition can't contribute to the result).

Overrides:

mayCreateNewNodes in class Instruction

Returns:

true if the instruction creates new nodes under some input conditions (or if it can't be proved that it doesn't)

export

public void export(ExpressionPresenter out)
            throws XPathException

Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.

Specified by:

export in interface ExportAgent

Specified by:

export in class Expression

Parameters:

out - the expression presenter used to display the structure

Throws:

XPathException - if the export fails, for example if an expression is found that won't work in the target environment.

getElaborator

public Elaborator getElaborator()

Make an elaborator for this expression

Overrides:

getElaborator in class Expression

Returns:

an appropriate Elaborator