Package net.sf.saxon.expr.instruct

Class GlobalVariable

    • Constructor Detail

      • GlobalVariable

        public GlobalVariable()
        Create a global variable

    • Method Detail

      • setExecutable

        public void setExecutable​(Executable executable)
        Set the containing executable
        Parameters:
        executable - the executable that contains this global variable

      • getLineNumber

        public int getLineNumber​(long locationId)
        Get the line number within the document, entity or module containing a particular location
        Specified by:
        getLineNumber in interface LocationProvider
        Parameters:
        locationId - identifier of the location in question (as passed down the Receiver pipeline)
        Returns:
        the line number within the document, entity or module, or -1 if no information is available.

      • getColumnNumber

        public int getColumnNumber​(long locationId)
        Get the column number within the document, entity, or module containing a particular location
        Specified by:
        getColumnNumber in interface LocationProvider
        Parameters:
        locationId - identifier of the location in question (as passed down the Receiver pipeline)
        Returns:
        the column number within the document, entity, or module, or -1 if this is not available

      • getConstructType

        public int getConstructType()
        Get the type of construct. This will either be the fingerprint of a standard XSLT instruction name (values in StandardNames: all less than 1024) or it will be a constant in class Location.
        Specified by:
        getConstructType in interface InstructionInfo
        Returns:
        an integer identifying the kind of construct

      • getObjectName

        public StructuredQName getObjectName()
        Get a name identifying the object of the expression, for example a function name, template name, variable name, key name, element name, etc. This is used only where the name is known statically.
        Specified by:
        getObjectName in interface InstructionInfo
        Returns:
        the QName of the object declared or manipulated by this instruction or expression

      • getProperty

        public java.lang.Object getProperty​(java.lang.String name)
        Get the value of a particular property of the instruction. Properties of XSLT instructions are generally known by the name of the stylesheet attribute that defines them.
        Specified by:
        getProperty in interface InstructionInfo
        Parameters:
        name - The name of the required property
        Returns:
        The value of the requested property, or null if the property is not available

      • getProperties

        public java.util.Iterator<java.lang.String> getProperties()
        Get an iterator over all the properties available. The values returned by the iterator will be of type String, and each string can be supplied as input to the getProperty() method to retrieve the value of the property. The iterator may return properties whose value is null.
        Specified by:
        getProperties in interface InstructionInfo
        Returns:
        an iterator over the properties.

      • getContainer

        public Container getContainer()
        Get the container in which this expression is located. This will usually be a top-level construct such as a function or global variable, and XSLT template, or an XQueryExpression. In the case of free-standing XPath expressions it will be the StaticContext object
        Overrides:
        getContainer in class GeneralVariable
        Returns:
        the expression's container

      • setIndexedVariable

        public void setIndexedVariable()
        Mark this as an indexed variable, to allow fast searching

      • isIndexedVariable

        public boolean isIndexedVariable()
        Ask whether this is an indexed variable
        Returns:
        true if this variable is indexed

      • getContainerGranularity

        public int getContainerGranularity()
        Get the granularity of the container.
        Specified by:
        getContainerGranularity in interface Container
        Returns:
        0 for a temporary container created during parsing; 1 for a container that operates at the level of an XPath expression; 2 for a container at the level of a global function or template

      • setContainsLocals

        public void setContainsLocals​(SlotManager map)
        The expression that initializes a global variable may itself use local variables. In this case a stack frame needs to be allocated while evaluating the global variable
        Parameters:
        map - The stack frame map for local variables used while evaluating this global variable.

      • isGlobal

        public boolean isGlobal()
        Is this a global variable?
        Specified by:
        isGlobal in interface Binding
        Overrides:
        isGlobal in class GeneralVariable
        Returns:
        true (yes, it is a global variable)

      • lookForCycles

        public void lookForCycles​(java.util.Stack<Container> referees,
                          XQueryFunctionLibrary globalFunctionLibrary)
                   throws XPathException
        Check for cycles in this variable definition
        Parameters:
        referees - the calls leading up to this one; it's an error if this variable is on the stack, because that means it calls itself directly or indirectly. The stack may contain variable definitions (GlobalVariable objects) and user-defined functions (UserFunction objects). It will never contain the same object more than once.
        globalFunctionLibrary - the library containing all global functions
        Throws:
        XPathException - if cycles are found

      • getSelectValue

        public ValueRepresentation getSelectValue​(XPathContext context)
                                   throws XPathException
        Evaluate the variable. That is, get the value of the select expression if present or the content of the element otherwise, either as a tree or as a sequence
        Overrides:
        getSelectValue in class GeneralVariable
        Parameters:
        context - the XPath dynamic context
        Returns:
        the result of evaluating the variable
        Throws:
        XPathException - if evaluation of the select expression fails with a dynamic error

      • actuallyEvaluate

        protected ValueRepresentation actuallyEvaluate​(XPathContext context)
                                        throws XPathException
        Evaluate the global variable, and save its value for use in subsequent references.
        Parameters:
        context - the XPath dynamic context
        Returns:
        the value of the variable
        Throws:
        XPathException - if evaluation fails

      • setDependencies

        protected static void setDependencies​(Bindery bindery,
                                      GlobalVariable var,
                                      XPathContext context)
                               throws XPathException
        Get the variable that is immediately dependent on this one, and register the dependency, so that circularities can be detected across threads. This relies on the fact that when the initialiser for variable X contains a reference to variable Y, then when Y is evaluated, a stack frame will be found on the context stack representing the evaluation of X. We don't set a dependency from X to Y if the value of Y was already available in the Bindery; it's not needed, because in this case we know that evaluation of Y is unproblematic, and can't lead to any circularities.
        Parameters:
        bindery - the Bindery
        var - the global variable or parameter being evaluated
        context - the dynamic evaluation context
        Throws:
        XPathException