Package net.sf.saxon.expr

Class EarlyEvaluationContext

java.lang.Object
net.sf.saxon.expr.EarlyEvaluationContext
All Implemented Interfaces:
Serializable, XPathContext
public class EarlyEvaluationContext extends Object implements XPathContext, Serializable
This class is an implementation of XPathContext used when evaluating constant sub-expressions at compile time.
See Also:

  • Constructor Details

    • EarlyEvaluationContext

      public EarlyEvaluationContext(Configuration config, CollationMap map)
      Create an early evaluation context, used for evaluating constant expressions at compile time
      Parameters:
      config - the Saxon configuration
      map - the available collations

  • Method Details

    • changeOutputDestination

      public void changeOutputDestination(Properties props, Result result, boolean isFinal, int hostLanguage, int validation, SchemaType schemaType) throws XPathException
      Set a new output destination, supplying the output format details.
      Note that it is the caller's responsibility to close the Writer after use.
      Specified by:
      changeOutputDestination in interface XPathContext
      Parameters:
      props - properties defining the output format
      result - Details of the new output destination
      isFinal - true if the destination is a final result tree (either the principal output or a secondary result tree); false if it is a temporary tree, xsl:attribute, etc.
      hostLanguage - the host language (XSLT, XQuery, XPath)
      validation - validation mode: strict, lax, preserve, or strip
      schemaType - type against which the output must be validated
      Throws:
      XPathException - if any dynamic error occurs; and specifically, if an attempt is made to switch to a final output destination while writing a temporary tree or sequence

    • evaluateLocalVariable

      public ValueRepresentation evaluateLocalVariable(int slotnumber)
      Get the value of a local variable, identified by its slot number
      Specified by:
      evaluateLocalVariable in interface XPathContext
      Parameters:
      slotnumber - the slot number allocated at compile time to the variable, which identifies its position within the local stack frame
      Returns:
      the value of the variable.

    • getCaller

      public XPathContext getCaller()
      Get the calling XPathContext (the next one down the stack). This will be null if unknown, or if the bottom of the stack has been reached.
      Specified by:
      getCaller in interface XPathContext
      Returns:
      the XPathContext of the calling expression

    • getCollation

      public StringCollator getCollation(String name) throws XPathException
      Get a named collation
      Specified by:
      getCollation in interface XPathContext
      Parameters:
      name - the name (URI) of the required collation
      Returns:
      a StringCollator representing the collation
      Throws:
      XPathException - if the collation is not recognized

    • getConfiguration

      public Configuration getConfiguration()
      Get the Configuration
      Specified by:
      getConfiguration in interface XPathContext
      Returns:
      the Saxon configuration object

    • getContextItem

      public Item getContextItem()
      Get the context item
      Specified by:
      getContextItem in interface XPathContext
      Returns:
      the context item, or null if the context item is undefined

    • getContextPosition

      public int getContextPosition() throws XPathException
      Get the context position (the position of the context item)
      Specified by:
      getContextPosition in interface XPathContext
      Returns:
      the context position (starting at one)
      Throws:
      XPathException - if the context position is undefined

    • getController

      public Controller getController()
      Get the Controller. May return null when running outside XSLT or XQuery
      Specified by:
      getController in interface XPathContext
      Returns:
      the controller for this query or transformation

    • 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
      Returns:
      the current grouped collection

    • getCurrentIterator

      public SequenceIterator getCurrentIterator()
      Get the current iterator. This encapsulates the context item, context position, and context size.
      Specified by:
      getCurrentIterator in interface XPathContext
      Returns:
      the current iterator, or null if there is no current iterator (which means the context item, position, and size are undefined).

    • getCurrentMode

      public Mode getCurrentMode()
      Get the current mode.
      Specified by:
      getCurrentMode in interface XPathContext
      Returns:
      the current mode

    • 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
      Returns:
      the current regular expressions iterator

    • getCurrentTemplateRule

      public Rule getCurrentTemplateRule()
      Get the current template. This is used to support xsl:apply-imports
      Specified by:
      getCurrentTemplateRule in interface XPathContext
      Returns:
      the current template

    • getDefaultCollation

      public StringCollator getDefaultCollation()
      Get the default collation
      Specified by:
      getDefaultCollation in interface XPathContext
      Returns:
      a StringCollator representing the default collation

    • getLast

      public int getLast() throws XPathException
      Get the context size (the position of the last item in the current node list)
      Specified by:
      getLast in interface XPathContext
      Returns:
      the context size
      Throws:
      XPathException - if the context position is undefined

    • getLocalParameters

      public ParameterSet getLocalParameters()
      Get the local (non-tunnel) parameters that were passed to the current function or template
      Specified by:
      getLocalParameters in interface XPathContext
      Returns:
      a ParameterSet containing the local parameters

    • getNamePool

      public NamePool getNamePool()
      Get the Name Pool
      Specified by:
      getNamePool in interface XPathContext
      Returns:
      the name pool

    • getOrigin

      public InstructionInfo getOrigin()
      Get information about the creating expression or other construct.
      Specified by:
      getOrigin in interface XPathContext
      Returns:
      information about the creating expression

    • getOriginatingConstructType

      public int getOriginatingConstructType()
      Get the type of location from which this context was created.
      Specified by:
      getOriginatingConstructType in interface XPathContext
      Returns:
      the type of location. (The integer codes that are used are often fingerprints of instruction names, but not always. For details of the codes, see the standard trace listener which interprets them)

    • getReceiver

      public SequenceReceiver getReceiver()
      Get the Receiver to which output is currently being written.
      Specified by:
      getReceiver in interface XPathContext
      Returns:
      the current Receiver

    • getStackFrame

      public StackFrame getStackFrame()
      Get a reference to the local stack frame for variables. Note that it's the caller's job to make a local copy of this. This is used for creating a Closure containing a retained copy of the variables for delayed evaluation.
      Specified by:
      getStackFrame in interface XPathContext
      Returns:
      array of variables.

    • getTunnelParameters

      public ParameterSet getTunnelParameters()
      Get the tunnel parameters that were passed to the current function or template. This includes all active tunnel parameters whether the current template uses them or not.
      Specified by:
      getTunnelParameters in interface XPathContext
      Returns:
      a ParameterSet containing the tunnel parameters

    • isAtLast

      public boolean isAtLast() throws XPathException
      Determine whether the context position is the same as the context size that is, whether position()=last()
      Specified by:
      isAtLast in interface XPathContext
      Returns:
      true if the context position is the same as the context size.
      Throws:
      XPathException

    • newCleanContext

      public XPathContextMajor newCleanContext()
      Construct a new context without copying (used for the context in a function call)
      Specified by:
      newCleanContext in interface XPathContext
      Returns:
      a new clean context

    • 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
      Returns:
      a new context, created as a copy of this context

    • newMinorContext

      public XPathContextMinor newMinorContext()
      Construct a new minor context. A minor context can only hold new values of the focus (currentIterator) and current output destination.
      Specified by:
      newMinorContext in interface XPathContext
      Returns:
      a new minor context

    • setCaller

      public void setCaller(XPathContext caller)
      Set the calling XPathContext
      Specified by:
      setCaller in interface XPathContext
      Parameters:
      caller - the XPathContext of the calling expression

    • setCurrentIterator

      public void setCurrentIterator(SequenceIterator iter)
      Set a new sequence iterator.
      Specified by:
      setCurrentIterator in interface XPathContext
      Parameters:
      iter - the current iterator. The context item, position, and size are determined by reference to the current iterator.

    • setLocalVariable

      public void setLocalVariable(int slotnumber, ValueRepresentation value)
      Set the value of a local variable, identified by its slot number
      Specified by:
      setLocalVariable in interface XPathContext
      Parameters:
      slotnumber - the slot number allocated at compile time to the variable, which identifies its position within the local stack frame
      value - the value of the variable

    • setOrigin

      public void setOrigin(InstructionInfo 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. Where possible, the object will be an Expression, allowing information about the calling instruction to be obtained.
      Specified by:
      setOrigin in interface XPathContext
      Parameters:
      expr - the expression that created this context object

    • setOriginatingConstructType

      public void setOriginatingConstructType(int loc)
      Set the type of creating expression (for use in diagnostics). When a new context is created, either this method or XPathContext.setOrigin(net.sf.saxon.trace.InstructionInfo) should be called.
      Specified by:
      setOriginatingConstructType in interface XPathContext
      Parameters:
      loc - The originating location: the argument must be one of the integer constants in class Location

    • setReceiver

      public void setReceiver(SequenceReceiver receiver)
      Change the Receiver to which output is written
      Specified by:
      setReceiver in interface XPathContext
      Parameters:
      receiver - the SequenceReceiver to be used

    • setTemporaryReceiver

      public void setTemporaryReceiver(SequenceReceiver out)
      Set the receiver to which output is to be written, marking it as a temporary (non-final) output destination.
      Specified by:
      setTemporaryReceiver in interface XPathContext
      Parameters:
      out - The SequenceOutputter to be used

    • 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
      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

    • getCurrentDateTime

      public DateTimeValue getCurrentDateTime() throws NoDynamicContextException
      Get the current date and time. This implementation always throws a NoDynamicContextException.
      Specified by:
      getCurrentDateTime in interface XPathContext
      Returns:
      the current date and time. All calls within a single query or transformation will return the same value
      Throws:
      NoDynamicContextException

    • getImplicitTimezone

      public int getImplicitTimezone() throws NoDynamicContextException
      Get the implicit timezone, as a positive or negative offset from UTC in minutes. The range is -14hours to +14hours. This implementation always throws a NoDynamicContextException.
      Specified by:
      getImplicitTimezone in interface XPathContext
      Returns:
      the implicit timezone, as an offset from UTC in minutes
      Throws:
      NoDynamicContextException

    • iterateStackFrames

      public Iterator iterateStackFrames()
      Get the context stack. This method returns an iterator whose items are instances of ContextStackFrame, starting with the top-most stackframe and ending at the point the query or transformation was invoked by a calling application.
      Specified by:
      iterateStackFrames in interface XPathContext
      Returns:
      an iterator over a copy of the run-time call stack