net.sf.saxon.expr.instruct

Class CallTemplate

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.instruct.Instruction

net.sf.saxon.expr.instruct.CallTemplate

All Implemented Interfaces:

ComponentInvocation, ContextOriginator, ExportAgent, ITemplateCall, TailCallReturner, Locatable, IdentityComparable

public class CallTemplate
extends Instruction
implements ITemplateCall, ComponentInvocation

Instruction representing an xsl:call-template element in the stylesheet.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CallTemplate.CallTemplatePackage A CallTemplatePackage is an object that encapsulates the name of a template to be called, the parameters to be supplied, and the execution context.

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 and Description
CallTemplate(NamedTemplate template, StructuredQName calledTemplateName, boolean useTailRecursion, boolean inStreamable) Construct a CallTemplate instruction.

Method Summary

Modifier and Type	Method and Description
int	computeCardinality() Get the cardinality of the sequence returned by evaluating this instruction
Expression	copy(RebindingMap rebindings) Copy an expression.
void	export(ExpressionPresenter out) Export of expression structure.
WithParam[]	getActualParams() Get the actual parameters passed to the called template
int	getBindingSlot() Get the binding slot to be used.
StructuredQName	getCalledTemplateName() Get the name (QName) of the template being called
Component	getFixedTarget() Get the target component if this is known in advance, that is, if the target component is private or final, or in some other cases such as xsl:original.
int	getInstructionNameCode() Return the name of this instruction.
int	getIntrinsicDependencies() Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions.
ItemType	getItemType() Get the item type of the items returned by evaluating this instruction
StructuredQName	getObjectName()
java.lang.String	getStreamerName() Get the (partial) name of a class that supports streaming of this kind of expression
SymbolicName	getSymbolicName() Get the symbolic name of the template being called.
Component	getTarget()
NamedTemplate	getTargetTemplate() Get the target template
WithParam[]	getTunnelParams() Get the tunnel parameters passed to the called template
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.
Expression	optimize(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) Perform optimisation of an expression and its subexpressions.
void	process(XPathContext context) Process this instruction, without leaving any tail calls.
TailCall	processLeavingTail(XPathContext context) Process this instruction.
void	setActualParameters(WithParam[] actualParams, WithParam[] tunnelParams) Set the actual parameters on the call
void	setBindingSlot(int slot) Set the binding slot to be used.
void	setTargetTemplate(NamedTemplate target) Set the target template
Expression	simplify() Simplify an expression.
java.lang.String	toShortString() Produce a short string identifying the expression for use in error messages
java.lang.String	toString() The toString() method for an expression attempts to give a representation of the expression in an XPath-like form.
Expression	typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) Perform type checking of an expression and its subexpressions.
boolean	usesTailRecursion() Ask whether this is a tail call

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

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

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

CallTemplate

public CallTemplate(NamedTemplate template,
                    StructuredQName calledTemplateName,
                    boolean useTailRecursion,
                    boolean inStreamable)

Construct a CallTemplate instruction.

Parameters:

template - the template to be called. This is provisional, and applies only if the template is not overridden in another package; the template supplied will be the one with matching name in the same package. Null in the case of saxon:call-template, and also in the case where the supplied name is xsl:original

calledTemplateName - the name of the template to be called; null in the case of saxon:call-template where this is established dynamically

useTailRecursion - true if the call is potentially tail recursive where the name of the called template is to be calculated dynamically

Method Detail

setActualParameters

public void setActualParameters(WithParam[] actualParams,
                                WithParam[] tunnelParams)

Set the actual parameters on the call

Parameters:

actualParams - the parameters that are not tunnel parameters

tunnelParams - the tunnel parameters

getCalledTemplateName

public StructuredQName getCalledTemplateName()

Get the name (QName) of the template being called

Returns:

the name of the target template

getSymbolicName

public SymbolicName getSymbolicName()

Get the symbolic name of the template being called. This is essentially the component kind (template) plus the QName of the target template

Specified by:

getSymbolicName in interface ComponentInvocation

Returns:

the symbolic name of the target template, or null in the case of saxon:call-template where the name is defined dynamically

getTarget

public Component getTarget()

getFixedTarget

public Component getFixedTarget()

Description copied from interface: ComponentInvocation

Get the target component if this is known in advance, that is, if the target component is private or final, or in some other cases such as xsl:original. Otherwise, return null.

Specified by:

getFixedTarget in interface ComponentInvocation

Returns:

the bound component if the binding has been fixed

getActualParams

public WithParam[] getActualParams()

Get the actual parameters passed to the called template

Specified by:

getActualParams in interface ITemplateCall

Returns:

the non-tunnel parameters

getTunnelParams

public WithParam[] getTunnelParams()

Get the tunnel parameters passed to the called template

Specified by:

getTunnelParams in interface ITemplateCall

Returns:

the tunnel parameters

setTargetTemplate

public void setTargetTemplate(NamedTemplate target)

Set the target template

Parameters:

target - the target template

getTargetTemplate

public NamedTemplate getTargetTemplate()

Get the target template

Returns:

the target template

usesTailRecursion

public boolean usesTailRecursion()

Ask whether this is a tail call

Returns:

true if this is a tail call

getInstructionNameCode

public int getInstructionNameCode()

Return the name of this instruction.

Overrides:

getInstructionNameCode in class Instruction

Returns:

a code identifying the instruction: typically but not always the fingerprint of a name in the XSLT namespace

setBindingSlot

public void setBindingSlot(int slot)

Set the binding slot to be used. This is the offset within the binding vector of the containing component where the actual target template is to be found. The target template is not held directly in the CallTemplate instruction itself because it can be overridden in a using package.

Specified by:

setBindingSlot in interface ComponentInvocation

Parameters:

slot - the offset in the binding vector of the containing package where the target template can be found.

getBindingSlot

public int getBindingSlot()

Get the binding slot to be used. This is the offset within the binding vector of the containing component where the actual target template is to be found.

Specified by:

getBindingSlot in interface ComponentInvocation

Returns:

the offset in the binding vector of the containing package where the target template can be found.

simplify

public Expression simplify()
                    throws XPathException

Simplify an expression. This performs any static optimization (by rewriting the expression as a different expression).

Overrides:

simplify in class Expression

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.

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)

optimize

public Expression optimize(ExpressionVisitor visitor,
                           ContextItemStaticInfo contextItemType)
                    throws XPathException

Description copied from class: Expression

Perform optimisation of an expression and its subexpressions. This is the third and final phase of static optimization.

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.

Overrides:

optimize in class Expression

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 if appropriate to optimize execution

Throws:

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

computeCardinality

public int computeCardinality()

Get the cardinality of the sequence returned by evaluating this instruction

Overrides:

computeCardinality in class Instruction

Returns:

the static cardinality

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

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

getIntrinsicDependencies

public int getIntrinsicDependencies()

Description copied from class: Expression

Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions. For example, position() has an intrinsic dependency on the context position, while (position()+1) does not. The default implementation of the method returns 0, indicating "no dependencies".

Overrides:

getIntrinsicDependencies in class Expression

Returns:

a set of bit-significant flags identifying the "intrinsic" dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty

mayCreateNewNodes

public final boolean mayCreateNewNodes()

Determine whether this instruction creates new nodes. This implementation currently returns true unconditionally.

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)

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. Default implementation works off the results of iterateSubExpressions()

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

process

public void process(XPathContext context)
             throws XPathException

Process this instruction, without leaving any tail calls.

Overrides:

process in class Instruction

Parameters:

context - the dynamic context for this transformation

Throws:

XPathException - if a dynamic error occurs

processLeavingTail

public TailCall processLeavingTail(XPathContext context)
                            throws XPathException

Process this instruction. If the called template contains a tail call (which may be an xsl:call-template or xsl:apply-templates instruction) then the tail call will not actually be evaluated, but will be returned in a TailCall object for the caller to execute.

Specified by:

processLeavingTail in interface TailCallReturner

Specified by:

processLeavingTail in class Instruction

Parameters:

context - the dynamic context for this transformation

Returns:

an object containing information about the tail call to be executed by the caller. Returns null if there is no tail call.

Throws:

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

getObjectName

public StructuredQName getObjectName()

Overrides:

getObjectName in class Expression

export

public void export(ExpressionPresenter out)
            throws XPathException

Export 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.

toString

public java.lang.String toString()

Description copied from class: Expression

The toString() method for an expression attempts to give a representation of the expression in an XPath-like form.

For subclasses of Expression that represent XPath expressions, the result should always be a string that parses as an XPath 3.0 expression. The expression produced should be equivalent to the original making certain assumptions about the static context. In general the expansion will make no assumptions about namespace bindings, except that (a) the prefix "xs" is used to refer to the XML Schema namespace, and (b) the default function namespace is assumed to be the "fn" namespace.

In the case of XSLT instructions and XQuery expressions, the toString() method gives an abstracted view of the syntax that is not designed in general to be parseable.

Overrides:

toString in class Expression

Returns:

a representation of the expression as a string

toShortString

public java.lang.String toShortString()

Description copied from class: Expression

Produce a short string identifying the expression for use in error messages

Overrides:

toShortString in class Expression

Returns:

a short string, sufficient to identify the expression

getStreamerName

public java.lang.String getStreamerName()

Description copied from class: Expression

Get the (partial) name of a class that supports streaming of this kind of expression

Overrides:

getStreamerName in class Expression

Returns:

the partial name of a class that can be instantiated to provide streaming support in Saxon-EE, or null if there is no such class