com.saxonica.xslt3.instruct

Class NextIteration

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.instruct.Instruction

com.saxonica.xslt3.instruct.NextIteration

All Implemented Interfaces:

SourceLocator, TailCallReturner, IdentityComparable, InstructionInfo

public class NextIteration
extends Instruction

Implements a xsl:next-iteration instruction within the body of xsl:iterate

Field Summary

Fields

Modifier and Type	Field and Description
static StructuredQName	XSL_NEXT_ITERATION

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

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

Constructor Summary

Constructors

Constructor and Description
NextIteration()

Method Summary

Methods

Modifier and Type	Method and Description
Expression	copy() Copy an expression.
void	explain(ExpressionPresenter out) Diagnostic print of expression structure.
ExpressionCompiler	getExpressionCompiler() Return the compiler of the NextIteration expression
WithParam[]	getParameters()
StreamingAdjunct	getStreamingAdjunct() Get a class that supports streamed evaluation of this expression
Iterable<Operand>	operands() Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression.
TailCall	processLeavingTail(XPathContext context) ProcessLeavingTail: called to do the real work of this instruction.
protected void	promoteInst(PromotionOffer offer) Handle promotion offers, that is, non-local tree rewrites.
boolean	replaceOperand(Expression original, Expression replacement) Replace one subexpression by a replacement subexpression
void	setParameters(WithParam[] actualParams)
Expression	simplify(ExpressionVisitor visitor) Simplify an expression.
Expression	typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) Perform type checking of an expression and its subexpressions.

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

assembleParams, assembleTunnelParams, computeCardinality, computeSpecialProperties, createsNewNodes, dynamicError, evaluateAsString, evaluateItem, getConstructType, getExpressionName, getImplementationMethod, getInstructionName, getInstructionNameCode, getItemType, getIteratorFromProcessMethod, getSourceLocator, isXSLT, iterate, process, promote, toStreamingPattern

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

addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, clearStreamabilityData, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getConfiguration, getContainer, getDependencies, getEvaluationMethod, getHostLanguage, getIntegerBounds, getIntrinsicDependencies, getLineNumber, getLocationId, getObjectName, getPosture, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getStreamability, getSweep, getSystemId, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isIdentical, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterateEvents, makeStreamingAdjunct, markTailFunctionCalls, operandList, optimize, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setFlattened, setLocationId, setPostureAndSweep, staticTypeCheck, suppressValidation, toPattern, toShortString, toString, typeError, unordered

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.xml.transform.SourceLocator

getColumnNumber, getLineNumber, getPublicId, getSystemId

Field Detail

XSL_NEXT_ITERATION

public static final StructuredQName XSL_NEXT_ITERATION

Constructor Detail

NextIteration

public NextIteration()

Method Detail

setParameters

public void setParameters(WithParam[] actualParams)

getParameters

public WithParam[] getParameters()

simplify

public Expression simplify(ExpressionVisitor visitor)
                    throws XPathException

Description copied from class: Expression

Simplify an expression. This performs any static optimization (by rewriting the expression as a different expression). The default implementation simplifies its operands.

Overrides:

simplify in class Expression

Parameters:

visitor - an expression visitor

Returns:

the simplified expression

Throws:

XPathException - if an error is discovered during expression rewriting

typeCheck

public Expression typeCheck(ExpressionVisitor visitor,
                   ContextItemStaticInfo contextInfo)
                     throws XPathException

Description copied from class: Expression

Perform type checking of an expression and its subexpressions. This is the second phase of static optimization.

This checks statically that the operands of the expression have the correct type; if necessary it generates code to do run-time type checking or type conversion. A static type error is reported only if execution cannot possibly succeed, that is, if a run-time type error is inevitable. The call may return a modified form of the expression.

This method is called after all references to functions and variables have been resolved to the declaration of the function or variable. However, the types of such functions and variables may not be accurately known if they have not been explicitly declared.

If the implementation returns a value other than "this", then it is required to ensure that the location information in the returned expression have been set up correctly. It should not rely on the caller to do this, although for historical reasons many callers do so.

Overrides:

typeCheck in class Expression

Parameters:

visitor - an expression visitor

contextInfo - Information available statically about the context item: whether it is (possibly) absent; its static type; its streaming posture.

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)

copy

public Expression copy()

Description copied from class: Expression

Copy an expression. This makes a deep copy.

Specified by:

copy in class Expression

Returns:

the copy of the original expression

promoteInst

protected void promoteInst(PromotionOffer offer)
                    throws XPathException

Description copied from class: Instruction

Handle promotion offers, that is, non-local tree rewrites.

Overrides:

promoteInst in class Instruction

Parameters:

offer - The type of rewrite being offered

Throws:

XPathException - if an error occurs

operands

public Iterable<Operand> operands()

Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression. Default implementation works off the results of iterateSubExpressions()

Overrides:

operands in class Expression

Returns:

an iterator containing the sub-expressions of this expression

replaceOperand

public boolean replaceOperand(Expression original,
                     Expression replacement)

Description copied from class: Expression

Replace one subexpression by a replacement subexpression

Overrides:

replaceOperand in class Expression

Parameters:

original - the original subexpression

replacement - the replacement subexpression

Returns:

true if the original subexpression is found

getStreamingAdjunct

public StreamingAdjunct getStreamingAdjunct()

Get a class that supports streamed evaluation of this expression

Overrides:

getStreamingAdjunct in class Expression

Returns:

the relevant StreamingAdjunct, or null if none is available

processLeavingTail

public TailCall processLeavingTail(XPathContext context)
                            throws XPathException

Description copied from class: Instruction

ProcessLeavingTail: called to do the real work of this instruction. This method must be implemented in each subclass. The results of the instruction are written to the current Receiver, which can be obtained via the Controller.

Specified by:

processLeavingTail in interface TailCallReturner

Specified by:

processLeavingTail in class Instruction

Parameters:

context - The dynamic context of the transformation, giving access to the current node, the current variables, etc.

Returns:

null if the instruction has completed execution; or a TailCall indicating a function call or template call that is delegated to the caller, to be made after the stack has been unwound so as to save stack space.

Throws:

XPathException - if a dynamic error occurs during the evaluation of the instruction

getExpressionCompiler

public ExpressionCompiler getExpressionCompiler()

Return the compiler of the NextIteration expression

Overrides:

getExpressionCompiler in class Expression

Returns:

the relevant ExpressionCompiler

explain

public void explain(ExpressionPresenter out)

Description copied from class: Expression

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

Specified by:

explain in class Expression

Parameters:

out - the expression presenter used to display the structure