Package net.sf.saxon.expr.instruct

Class GeneralVariable

  • All Implemented Interfaces:
    javax.xml.transform.SourceLocator, Binding
    Direct Known Subclasses:
    GlobalVariable, LocalParam, LocalVariable, WithParam
    public abstract class GeneralVariable
extends java.lang.Object
implements Binding, javax.xml.transform.SourceLocator
    This class defines common behaviour across xsl:variable, xsl:param, and xsl:with-param; also saxon:assign

    • Field Detail

      • slotNumber

        protected int slotNumber

      • referenceCount

        protected int referenceCount

      • evaluationMode

        protected int evaluationMode

    • Constructor Detail

      • GeneralVariable

        public GeneralVariable()
        Create a general variable

    • Method Detail

      • init

        public void init​(Expression select,
                 StructuredQName qName)
        Initialize the properties of the variable
        Parameters:
        select - the expression to which the variable is bound
        qName - the name of the variable

      • setContainer

        public void setContainer​(Container container)
        Mark a variable as being in a given Container. This link is used primarily for diagnostics: the container links to the location map held in the executable.

        This affects the expression and all its subexpressions. Any subexpressions that are not in the same container are marked with the new container, and this proceeds recursively. However, any subexpression that is already in the correct container is not modified.

        Parameters:
        container - The container of this expression.

      • 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
        Returns:
        the expression's container

      • setLocationId

        public void setLocationId​(int id)
        Set the location ID on an expression.
        Parameters:
        id - the location id

      • getLocationId

        public final int getLocationId()
        Get the location ID of the expression
        Returns:
        a location identifier, which can be turned into real location information by reference to a location provider

      • getLineNumber

        public int getLineNumber()
        Get the line number of the expression
        Specified by:
        getLineNumber in interface javax.xml.transform.SourceLocator

      • getColumnNumber

        public int getColumnNumber()
        Get the column number of the expression
        Specified by:
        getColumnNumber in interface javax.xml.transform.SourceLocator

      • getSystemId

        public java.lang.String getSystemId()
        Get the systemId of the module containing the expression
        Specified by:
        getSystemId in interface javax.xml.transform.SourceLocator

      • getPublicId

        public final java.lang.String getPublicId()
        Get the publicId of the module containing the expression (to satisfy the SourceLocator interface)
        Specified by:
        getPublicId in interface javax.xml.transform.SourceLocator

      • getExecutable

        public Executable getExecutable()
        Get the executable containing this expression
        Returns:
        the containing Executable

      • getLocationProvider

        public LocationProvider getLocationProvider()
        Get the LocationProvider allowing location identifiers to be resolved.
        Returns:
        the LocationProvider used to turn the location id into real location information

      • getSystemId

        public java.lang.String getSystemId​(long locationId)

      • setSelectExpression

        public void setSelectExpression​(Expression select)
        Set the expression to which this variable is bound
        Parameters:
        select - the initializing expression

      • getSelectExpression

        public Expression getSelectExpression()
        Get the expression to which this variable is bound
        Returns:
        the initializing expression

      • setRequiredType

        public void setRequiredType​(SequenceType required)
        Set the required type of this variable
        Parameters:
        required - the required type

      • getRequiredType

        public SequenceType getRequiredType()
        Get the required type of this variable
        Specified by:
        getRequiredType in interface Binding
        Returns:
        the required type

      • getIntegerBoundsForVariable

        public IntegerValue[] getIntegerBoundsForVariable()
        If the variable is bound to an integer, get the minimum and maximum possible values. Return null if unknown or not applicable
        Specified by:
        getIntegerBoundsForVariable in interface Binding
        Returns:
        a pair of integers containing the minimum and maximum values for the integer value; or null if the value is not an integer or the range is unknown

      • setAssignable

        public void setAssignable​(boolean assignable)
        Indicate whether this variable is assignable using saxon:assign
        Parameters:
        assignable - true if this variable is assignable

      • setRequiredParam

        public void setRequiredParam​(boolean requiredParam)
        Indicate that this variable represents a required parameter
        Parameters:
        requiredParam - true if this is a required parameter

      • setImplicitlyRequiredParam

        public void setImplicitlyRequiredParam​(boolean requiredParam)
        Indicate that this variable represents a parameter that is implicitly required (because there is no usable default value)
        Parameters:
        requiredParam - true if this is an implicitly required parameter

      • setTunnel

        public void setTunnel​(boolean tunnel)
        Indicate whether this variable represents a tunnel parameter
        Parameters:
        tunnel - true if this is a tunnel parameter

      • setReferenceCount

        public void setReferenceCount​(int refCount)
        Set the nominal number of references to this variable
        Parameters:
        refCount - the nominal number of references

      • getEvaluationMode

        public int getEvaluationMode()
        Get the evaluation mode of the variable
        Returns:
        the evaluation mode (a constant in ExpressionTool

      • isAssignable

        public final boolean isAssignable()
        Test whether it is permitted to assign to the variable using the saxon:assign extension element. This will only be true if the extra attribute saxon:assignable="yes" is present.
        Specified by:
        isAssignable in interface Binding
        Returns:
        true if the binding is assignable

      • getCardinality

        public int getCardinality()
        Get the cardinality of the result of this instruction. An xsl:variable instruction returns nothing, so the type is empty.
        Returns:
        the empty cardinality.

      • isGlobal

        public boolean isGlobal()
        Description copied from interface: Binding
        Indicate whether the binding is local or global. A global binding is one that has a fixed value for the life of a query or transformation; any other binding is local.
        Specified by:
        isGlobal in interface Binding
        Returns:
        true if the binding is global

      • getLocalSlotNumber

        public int getLocalSlotNumber()
        If this is a local variable held on the local stack frame, return the corresponding slot number. In other cases, return -1.
        Specified by:
        getLocalSlotNumber in interface Binding
        Returns:
        the slot number on the local stack frame

      • isRequiredParam

        public final boolean isRequiredParam()
        Ask whether this variable represents a required parameter
        Returns:
        true if this is a required parameter

      • isImplicitlyRequiredParam

        public final boolean isImplicitlyRequiredParam()
        Ask whether this variable represents a parameter that is implicitly required, because there is no usable default value
        Returns:
        true if this variable is an implicitly required parameter

      • isTunnelParam

        public final boolean isTunnelParam()
        Ask whether this variable represents a tunnel parameter
        Returns:
        true if this is a tunnel parameter

      • getInstructionNameCode

        public int getInstructionNameCode()
        Get the name of this instruction (that is xsl:variable, xsl:param etc) for diagnostics
        Returns:
        the name of this instruction, as a name pool name code

      • computeEvaluationMode

        public void computeEvaluationMode()

      • copy

        public Expression copy()
        Copy an expression. This makes a deep copy.
        Returns:
        the copy of the original expression

      • addReference

        public void addReference​(boolean isLoopingReference)
        Description copied from interface: Binding
        Register a variable reference that refers to the variable bound in this expression
        Specified by:
        addReference in interface Binding
        Parameters:
        isLoopingReference - - true if the reference occurs within a loop, such as the predicate of a filter expression

      • checkAgainstRequiredType

        public void checkAgainstRequiredType​(ExpressionVisitor visitor)
                              throws XPathException
        Check the select expression against the required type.
        Parameters:
        visitor - an expression visitor
        Throws:
        XPathException - if the check fails

      • 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
        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

      • iterateSubExpressions

        public java.util.Iterator<Expression> iterateSubExpressions()
        Get all the XPath expressions associated with this instruction (in XSLT terms, the expression present on attributes of the instruction, as distinct from the child instructions in a sequence construction)
        Returns:
        an iterator over all the contained expressions (in practice, the select expression)

      • replaceSubExpression

        public boolean replaceSubExpression​(Expression original,
                                    Expression replacement)
        Replace one subexpression by a replacement subexpression
        Parameters:
        original - the original subexpression
        replacement - the replacement subexpression
        Returns:
        true if the original subexpression is found

      • explain

        public void explain​(ExpressionPresenter out)
        Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
        Parameters:
        out - the object used to present the output

      • getSlotNumber

        public int getSlotNumber()
        Get the slot number allocated to this variable
        Returns:
        the slot number, that is the position allocated to the variable on its stack frame

      • setSlotNumber

        public void setSlotNumber​(int s)
        Set the slot number of this variable
        Parameters:
        s - the slot number, that is, the position allocated to this variable on its stack frame

      • setVariableQName

        public void setVariableQName​(StructuredQName s)
        Set the name of the variable
        Parameters:
        s - the name of the variable (a QName)

      • getVariableQName

        public StructuredQName getVariableQName()
        Get the name of this variable
        Specified by:
        getVariableQName in interface Binding
        Returns:
        the name of this variable (a QName)