Package net.sf.saxon.expr

Class 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 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

      • setLocalParameters

        public void setLocalParameters​(ParameterSet localParameters)
        Set the local parameters for the current template call.
        Parameters:
        localParameters - the supplied 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​(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. The object will either be an Expression, 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. This array will be copied if it is too small to hold all the variables defined in the SlotManager

      • 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

      • 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

      • 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

      • 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

      • 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