net.sf.saxon.expr
Class XPathContextMajor

java.lang.Object
  net.sf.saxon.expr.XPathContextMinor
      net.sf.saxon.expr.XPathContextMajor

All Implemented Interfaces:

XPathContext

public class XPathContextMajor
extends XPathContextMinor

This class represents a "major context" in which an XPath expression is evaluated: a "major context" object allows all aspects of the dynamic context to change, whereas a "minor context" only allows changes to the focus and the destination for push output.

Constructor Summary

XPathContextMajor(Controller controller)
Constructor should only be called by the Controller, which acts as a XPathContext factory.

XPathContextMajor(Item item, Configuration config)
Deprecated. since 9.0 - use XPathContextMajor(Item, Executable)

XPathContextMajor(Item item, Executable exec)
Constructor for use in free-standing Java applications.

Method Summary

GroupIterator	getCurrentGroupIterator() Get the current group iterator.
Mode	getCurrentMode() Get the current mode.
RegexIterator	getCurrentRegexIterator() Get the current regex iterator.
Rule	getCurrentTemplateRule() Get the current template.
ParameterSet	getLocalParameters() Get the local parameters for the current template call.
UserFunction	getTailCallFunction() Determine whether the body of a function is to be repeated, due to tail-recursive function calls
ParameterSet	getTunnelParameters() Get the tunnel parameters for the current template call.
XPathContextMajor	newContext() Construct a new context as a copy of another.
static XPathContextMajor	newContext(XPathContextMinor prev) Create a new "major" context (one that is capable of holding a stack frame with local variables
void	openStackFrame(int numberOfVariables) Create a new stack frame large enough to hold a given number of local variables, for which no stack frame map is available.
void	openStackFrame(SlotManager map) Create a new stack frame for local variables, using the supplied SlotManager to define the allocation of slots to individual variables
void	requestTailCall(UserFunction fn, ValueRepresentation[] variables) Reset the local stack frame.
void	resetStackFrameMap(SlotManager map, int numberOfParams) Reset the stack frame variable map, while reusing the StackFrame object itself.
void	setCurrentGroupIterator(GroupIterator iterator) Set the current grouping iterator.
void	setCurrentMode(Mode mode) Set the current mode.
void	setCurrentRegexIterator(RegexIterator currentRegexIterator) Set the current regex iterator.
void	setCurrentTemplateRule(Rule rule) Set the current template.
void	setLocalParameters(ParameterSet localParameters) Set the local parameters for the current template call.
void	setOrigin(InstructionInfoProvider expr) Set the creating expression (for use in diagnostics).
void	setStackFrame(SlotManager map, ValueRepresentation[] variables) Set the local stack frame.
void	setTunnelParameters(ParameterSet tunnelParameters) Set the tunnel parameters for the current template call.
boolean	useLocalParameter(StructuredQName qName, LocalParam binding, boolean isTunnel) Use local parameter.

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

changeOutputDestination, evaluateLocalVariable, getCaller, getCollation, getConfiguration, getContextItem, getContextPosition, getController, getCurrentDateTime, getCurrentIterator, getDefaultCollation, getImplicitTimezone, getLast, getNameChecker, getNamePool, getOrigin, getOriginatingConstructType, getReceiver, getStackFrame, isAtLast, newCleanContext, newMinorContext, setCaller, setCurrentIterator, setLocalVariable, setOriginatingConstructType, setReceiver, setTemporaryReceiver

Methods inherited from class java.lang.Object

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

Constructor Detail

XPathContextMajor

public XPathContextMajor(Controller controller)

Constructor should only be called by the Controller, which acts as a XPathContext factory.

Parameters:

controller - the Controller

XPathContextMajor

public XPathContextMajor(Item item,
                         Executable exec)

Constructor for use in free-standing Java applications.

Parameters:

item - the item to use as the initial context item. If this is null, the comtext item is initially undefined (which will cause a dynamic error if it is referenced).

exec - the Executable

XPathContextMajor

public XPathContextMajor(Item item,
                         Configuration config)

Deprecated. since 9.0 - use XPathContextMajor(Item, Executable)

Constructor for use in free-standing Java applications.

Parameters:

item - the item to use as the initial context item. If this is null, the comtext item is initially undefined (which will cause a dynamic error if it is referenced).

config - the Saxon Configuration

Method Detail

newContext

public XPathContextMajor newContext()

Construct a new context as a copy of another. The new context is effectively added to the top of a stack, and contains a pointer to the previous context

Specified by:

newContext in interface XPathContext

Overrides:

newContext in class XPathContextMinor

Returns:

a new context, created as a copy of this context

newContext

public static XPathContextMajor newContext(XPathContextMinor prev)

Create a new "major" context (one that is capable of holding a stack frame with local variables

Parameters:

prev - the previous context (the one causing the new context to be created)

Returns:

the new major context

getLocalParameters

public ParameterSet getLocalParameters()

Get the local parameters for the current template call.

Specified by:

getLocalParameters in interface XPathContext

Overrides:

getLocalParameters in class XPathContextMinor

Returns:

the supplied parameters

setLocalParameters

public void setLocalParameters(ParameterSet localParameters)

Set the local parameters for the current template call.

Parameters:

localParameters - the supplied parameters

getTunnelParameters

public ParameterSet getTunnelParameters()

Get the tunnel parameters for the current template call.

Specified by:

getTunnelParameters in interface XPathContext

Overrides:

getTunnelParameters in class XPathContextMinor

Returns:

the supplied tunnel parameters

setTunnelParameters

public void setTunnelParameters(ParameterSet tunnelParameters)

Set the tunnel parameters for the current template call.

Parameters:

tunnelParameters - the supplied tunnel parameters

setOrigin

public void setOrigin(InstructionInfoProvider expr)

Set the creating expression (for use in diagnostics). The origin is generally set to "this" by the object that creates the new context. It's up to the debugger to determine whether this information is useful. The object will either be an InstructionInfoProvider, allowing information about the calling instruction to be obtained, or null.

Specified by:

setOrigin in interface XPathContext

Overrides:

setOrigin in class XPathContextMinor

Parameters:

expr - the expression that created this context object

setStackFrame

public void setStackFrame(SlotManager map,
                          ValueRepresentation[] variables)

Set the local stack frame. This method is used when creating a Closure to support delayed evaluation of expressions. The "stack frame" is actually on the Java heap, which means it can survive function returns and the like.

Parameters:

map - the SlotManager, which holds static details of the allocation of variables to slots

variables - the array of "slots" to hold the actual variable values

resetStackFrameMap

public void resetStackFrameMap(SlotManager map,
                               int numberOfParams)

Reset the stack frame variable map, while reusing the StackFrame object itself. This is done on a tail call to a different function

Parameters:

map - the SlotManager representing the stack frame contents

numberOfParams - the number of parameters required on the new stack frame

requestTailCall

public void requestTailCall(UserFunction fn,
                            ValueRepresentation[] variables)

Reset the local stack frame. This method is used when processing a tail-recursive function. Instead of the function being called recursively, the parameters are set to new values and the function body is evaluated repeatedly

Parameters:

fn - the user function being called using tail recursion

variables - the parameter to be supplied to the user function

getTailCallFunction

public UserFunction getTailCallFunction()

Determine whether the body of a function is to be repeated, due to tail-recursive function calls

Returns:

null if no tail call has been requested, or the name of the function to be called otherwise

openStackFrame

public void openStackFrame(SlotManager map)

Create a new stack frame for local variables, using the supplied SlotManager to define the allocation of slots to individual variables

Parameters:

map - the SlotManager for the new stack frame

openStackFrame

public void openStackFrame(int numberOfVariables)

Create a new stack frame large enough to hold a given number of local variables, for which no stack frame map is available. This is used in particular when evaluating match patterns of template rules.

Parameters:

numberOfVariables - The number of local variables to be accommodated.

setCurrentMode

public void setCurrentMode(Mode mode)

Set the current mode.

Parameters:

mode - the new current mode

getCurrentMode

public Mode getCurrentMode()

Get the current mode.

Specified by:

getCurrentMode in interface XPathContext

Overrides:

getCurrentMode in class XPathContextMinor

Returns:

the current mode. May return null if the current mode is the default mode.

setCurrentTemplateRule

public void setCurrentTemplateRule(Rule rule)

Set the current template. This is used to support xsl:apply-imports. The caller is responsible for remembering the previous current template and resetting it after use.

Parameters:

rule - the current template rule

getCurrentTemplateRule

public Rule getCurrentTemplateRule()

Get the current template. This is used to support xsl:apply-imports

Specified by:

getCurrentTemplateRule in interface XPathContext

Overrides:

getCurrentTemplateRule in class XPathContextMinor

Returns:

the current template

setCurrentGroupIterator

public void setCurrentGroupIterator(GroupIterator iterator)

Set the current grouping iterator. This supports the current-group() and current-grouping-key() functions in XSLT 2.0

Parameters:

iterator - the new current GroupIterator

getCurrentGroupIterator

public GroupIterator getCurrentGroupIterator()

Get the current group iterator. This supports the current-group() and current-grouping-key() functions in XSLT 2.0

Specified by:

getCurrentGroupIterator in interface XPathContext

Overrides:

getCurrentGroupIterator in class XPathContextMinor

Returns:

the current grouped collection

setCurrentRegexIterator

public void setCurrentRegexIterator(RegexIterator currentRegexIterator)

Set the current regex iterator. This supports the functionality of the regex-group() function in XSLT 2.0.

Parameters:

currentRegexIterator - the current regex iterator

getCurrentRegexIterator

public RegexIterator getCurrentRegexIterator()

Get the current regex iterator. This supports the functionality of the regex-group() function in XSLT 2.0.

Specified by:

getCurrentRegexIterator in interface XPathContext

Overrides:

getCurrentRegexIterator in class XPathContextMinor

Returns:

the current regular expressions iterator

useLocalParameter

public boolean useLocalParameter(StructuredQName qName,
                                 LocalParam binding,
                                 boolean isTunnel)
                          throws XPathException

Use local parameter. This is called when a local xsl:param element is processed. If a parameter of the relevant name was supplied, it is bound to the xsl:param element. Otherwise the method returns false, so the xsl:param default will be evaluated

Specified by:

useLocalParameter in interface XPathContext

Overrides:

useLocalParameter in class XPathContextMinor

Parameters:

qName - The fingerprint of the parameter name

binding - The XSLParam element to bind its value to

isTunnel - True if a tunnel parameter is required, else false

Returns:

true if a parameter of this name was supplied, false if not

Throws:

XPathException