net.sf.saxon.instruct

Class ProcessingInstruction

java.lang.Object

net.sf.saxon.expr.ComputedExpression

net.sf.saxon.instruct.Instruction

net.sf.saxon.instruct.SimpleNodeConstructor

net.sf.saxon.instruct.ProcessingInstruction

All Implemented Interfaces:

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

public class ProcessingInstruction
extends SimpleNodeConstructor

An xsl:processing-instruction element in the stylesheet.

See Also:

Serialized Form

Field Summary

Fields inherited from class net.sf.saxon.instruct.SimpleNodeConstructor

select

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
ProcessingInstruction(Expression name) Create an xsl:processing-instruction instruction

Method Summary

Modifier and Type	Method and Description
protected java.lang.String	checkContent(java.lang.String data, XPathContext context) Check the content of the node, and adjust it if necessary
void	display(int level, java.io.PrintStream out, Configuration config) Display this instruction as an expression, for diagnostics
int	evaluateNameCode(XPathContext context)
int	getCardinality() Determine the static cardinality of the expression.
int	getDependencies() Determine which aspects of the context the expression depends on.
int	getInstructionNameCode() Get the name of this instruction for diagnostic and tracing purposes
ItemType	getItemType(TypeHierarchy th) Get the item type of the items returned by evaluating this instruction
java.util.Iterator	iterateSubExpressions() Get the immediate sub-expressions of this expression.
void	localTypeCheck(StaticContext env, ItemType contextItemType)
TailCall	processLeavingTail(XPathContext context) Process this instruction, that is, produce a processing-instruction node in the result sequence.
protected void	promoteInst(PromotionOffer offer) Offer promotion for subexpressions.
boolean	replaceSubExpression(Expression original, Expression replacement) Replace one subexpression by a replacement subexpression
Expression	simplify(StaticContext env) Simplify an expression.

Methods inherited from class net.sf.saxon.instruct.SimpleNodeConstructor

computeSpecialProperties, createsNewNodes, evaluateItem, expandChildren, getSelect, iterate, optimize, setSelect, typeCheck

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

appendItem, assembleParams, assembleTunnelParams, computeCardinality, dynamicError, evaluateAsString, getImplementationMethod, getInstructionInfo, getSourceLocator, isXSLT, process, promote

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

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.xml.transform.SourceLocator

getColumnNumber, getLineNumber, getPublicId, getSystemId

Constructor Detail

ProcessingInstruction

public ProcessingInstruction(Expression name)

Create an xsl:processing-instruction instruction

Parameters:

name - the expression used to compute the name of the generated processing-instruction

Method Detail

getInstructionNameCode

public int getInstructionNameCode()

Get the name of this instruction for diagnostic and tracing purposes

Overrides:

getInstructionNameCode in class Instruction

Returns:

the string "xsl:processing-instruction"

getItemType

public ItemType getItemType(TypeHierarchy th)

Description copied from class: Instruction

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

Specified by:

getItemType in interface Expression

Overrides:

getItemType in class Instruction

Returns:

the static item type of the instruction

getCardinality

public int getCardinality()

Description copied from class: ComputedExpression

Determine the static cardinality of the expression. This establishes how many items there will be in the result of the expression, at compile time (i.e., without actually evaluating the result.

Specified by:

getCardinality in interface Expression

Overrides:

getCardinality in class ComputedExpression

Returns:

one of the values Cardinality.ONE_OR_MORE, Cardinality.ZERO_OR_MORE, Cardinality.EXACTLY_ONE, Cardinality.ZERO_OR_ONE, Cardinality.EMPTY. This default implementation returns ZERO_OR_MORE (which effectively gives no information).

simplify

public Expression simplify(StaticContext env)
                    throws XPathException

Description copied from class: Instruction

Simplify an expression. This performs any static optimization (by rewriting the expression as a different expression). The default implementation does nothing.

Specified by:

simplify in interface Expression

Overrides:

simplify in class SimpleNodeConstructor

Parameters:

env - the static context

Returns:

the simplified expression

Throws:

XPathException - if an error is discovered during expression rewriting

localTypeCheck

public void localTypeCheck(StaticContext env,
                           ItemType contextItemType)
                    throws XPathException

Specified by:

localTypeCheck in class SimpleNodeConstructor

Throws:

XPathException

getDependencies

public int getDependencies()

Description copied from class: ComputedExpression

Determine which aspects of the context the expression depends on. The result is a bitwise-or'ed value composed from constants such as XPathContext.VARIABLES and XPathContext.CURRENT_NODE. The default implementation combines the intrinsic dependencies of this expression with the dependencies of the subexpressions, computed recursively. This is overridden for expressions such as FilterExpression where a subexpression's dependencies are not necessarily inherited by the parent expression.

Specified by:

getDependencies in interface Expression

Overrides:

getDependencies in class ComputedExpression

Returns:

a set of bit-significant flags identifying the dependencies of the expression

iterateSubExpressions

public java.util.Iterator iterateSubExpressions()

Description copied from class: ComputedExpression

Get the immediate sub-expressions of this expression. Default implementation returns a zero-length array, appropriate for an expression that has no sub-expressions.

Specified by:

iterateSubExpressions in interface Expression

Overrides:

iterateSubExpressions in class SimpleNodeConstructor

Returns:

an iterator containing the sub-expressions of this expression

replaceSubExpression

public boolean replaceSubExpression(Expression original,
                                    Expression replacement)

Replace one subexpression by a replacement subexpression

Specified by:

replaceSubExpression in interface Container

Overrides:

replaceSubExpression in class SimpleNodeConstructor

Parameters:

original - the original subexpression

replacement - the replacement subexpression

Returns:

true if the original subexpression is found

promoteInst

protected void promoteInst(PromotionOffer offer)
                    throws XPathException

Offer promotion for subexpressions. The offer will be accepted if the subexpression is not dependent on the factors (e.g. the context item) identified in the PromotionOffer. By default the offer is not accepted - this is appropriate in the case of simple expressions such as constant values and variable references where promotion would give no performance advantage. This method is always called at compile time.

Overrides:

promoteInst in class SimpleNodeConstructor

Parameters:

offer - details of the offer, for example the offer to move expressions that don't depend on the context to an outer level in the containing expression

Throws:

XPathException - if any error is detected

processLeavingTail

public TailCall processLeavingTail(XPathContext context)
                            throws XPathException

Process this instruction, that is, produce a processing-instruction node in the result sequence.

Specified by:

processLeavingTail in interface TailCallReturner

Specified by:

processLeavingTail in class Instruction

Parameters:

context - the dynamic context of this transformation

Returns:

always returns null in this implementation

Throws:

XPathException - if any non-recoverable dynamic error occurs

checkContent

protected java.lang.String checkContent(java.lang.String data,
                                        XPathContext context)
                                 throws DynamicError

Check the content of the node, and adjust it if necessary

Overrides:

checkContent in class SimpleNodeConstructor

Parameters:

data - the supplied content

context - the dynamic context

Returns:

the original content, unless adjustments are needed

Throws:

DynamicError - if the content is invalid

evaluateNameCode

public int evaluateNameCode(XPathContext context)
                     throws XPathException

Overrides:

evaluateNameCode in class SimpleNodeConstructor

Throws:

XPathException

display

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

Description copied from class: SimpleNodeConstructor

Display this instruction as an expression, for diagnostics

Specified by:

display in interface Expression

Overrides:

display in class SimpleNodeConstructor

Parameters:

level - indentation level for this expression

out - Output destination