Package net.sf.saxon.expr

Class UserFunctionCall

    • Constructor Detail

      • UserFunctionCall

        public UserFunctionCall()
        Create a function call to a user-written function in a query or stylesheet

    • Method Detail

      • isBeingInlined

        public boolean isBeingInlined()

      • setBeingInlined

        public void setBeingInlined​(boolean beingInlined)

      • setFunctionName

        public final void setFunctionName​(StructuredQName name)
        Set the name of the function being called
        Parameters:
        name - the name of the function

      • setStaticType

        public void setStaticType​(SequenceType type)
        Set the static type
        Parameters:
        type - the static type of the result of the function call

      • setFunction

        public void setFunction​(UserFunction compiledFunction)
        Create the reference to the function to be called
        Specified by:
        setFunction in interface UserFunctionResolvable
        Parameters:
        compiledFunction - the function being called

      • setBindingSlot

        public void setBindingSlot​(int slot)
        Set the binding slot to be used. This is the offset within the binding vector of the containing component where the actual target template is to be found. The target function is not held directly in the UserFunctionCall expression itself because it can be overridden in a using package.
        Specified by:
        setBindingSlot in interface ComponentInvocation
        Parameters:
        slot - the offset in the binding vector of the containing package where the target template can be found.

      • getBindingSlot

        public int getBindingSlot()
        Get the binding slot to be used. This is the offset within the binding vector of the containing component where the actual target template is to be found.
        Specified by:
        getBindingSlot in interface ComponentInvocation
        Returns:
        the offset in the binding vector of the containing package where the target template can be found.

      • getFunction

        public UserFunction getFunction()
        Get the function that is being called by this function call. This is the provisional binding: the actual function might be an override of this one.
        Returns:
        the function being called

      • getFixedTarget

        public Component getFixedTarget()
        Description copied from interface: ComponentInvocation
        Get the target component if this is known in advance, that is, if the target component is private or final, or in some other cases such as xsl:original. Otherwise, return null.
        Specified by:
        getFixedTarget in interface ComponentInvocation
        Returns:
        the bound component if the binding has been fixed

      • isTailCall

        public boolean isTailCall()
        Determine whether this is a tail call (not necessarily a recursive tail call)
        Returns:
        true if this function call is a tail call

      • isRecursiveTailCall

        public boolean isRecursiveTailCall()

      • getSymbolicName

        public SymbolicName getSymbolicName()
        Description copied from interface: ComponentInvocation
        Get the symbolic name of the component that this invocation references
        Specified by:
        getSymbolicName in interface ComponentInvocation
        Returns:
        the symbolic name of the target component, or null if there is no component referenced

      • setArgumentEvaluators

        public void setArgumentEvaluators​(Evaluator[] evalModes)
        Set the argument evaluation modes
        Parameters:
        evalModes - the argument evaluation modes to be used

      • allocateArgumentEvaluators

        public void allocateArgumentEvaluators()

      • getArgumentEvaluators

        public Evaluator[] getArgumentEvaluators()

      • preEvaluate

        public Expression preEvaluate​(ExpressionVisitor visitor)
        Pre-evaluate a function at compile time. This version of the method suppresses early evaluation by doing nothing.
        Overrides:
        preEvaluate in class FunctionCall
        Parameters:
        visitor - an expression visitor
        Returns:
        the result of the early evaluation, or the original expression, or potentially a simplified expression

      • getItemType

        public ItemType getItemType()
        Determine the data type of the expression, if possible
        Specified by:
        getItemType in class Expression
        Returns:
        Type.ITEM (meaning not known in advance)

      • getStaticUType

        public UType getStaticUType​(UType contextItemType)
        Get the static type of the expression as a UType, following precisely the type inference rules defined in the XSLT 3.0 specification.
        Overrides:
        getStaticUType in class Expression
        Parameters:
        contextItemType - the static type of the context item
        Returns:
        the static item type of the expression according to the XSLT 3.0 defined rules

      • getIntrinsicDependencies

        public int getIntrinsicDependencies()
        Description copied from class: Expression
        Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions. For example, position() has an intrinsic dependency on the context position, while (position()+1) does not. The default implementation of the method returns 0, indicating "no dependencies".
        Overrides:
        getIntrinsicDependencies in class Expression
        Returns:
        a set of bit-significant flags identifying the "intrinsic" dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty

      • isUpdatingExpression

        public boolean isUpdatingExpression()
        Determine whether this is an updating expression as defined in the XQuery update specification
        Overrides:
        isUpdatingExpression in class Expression
        Returns:
        true if this is an updating expression

      • computeSpecialProperties

        protected int computeSpecialProperties()
        Compute the special properties of this expression. These properties are denoted by a bit-significant integer, possible values are in class StaticProperty. The "special" properties are properties other than cardinality and dependencies, and most of them relate to properties of node sequences, for example whether the nodes are in document order.
        Overrides:
        computeSpecialProperties in class Expression
        Returns:
        the special properties, as a bit-significant integer

      • copy

        public Expression copy​(RebindingMap rebindings)
        Copy an expression. This makes a deep copy.
        Specified by:
        copy in class Expression
        Parameters:
        rebindings - variable bindings that need to be changed
        Returns:
        the copy of the original expression

      • typeCheck

        public Expression typeCheck​(ExpressionVisitor visitor,
                            ContextItemStaticInfo contextInfo)
                     throws XPathException
        Description copied from class: FunctionCall
        Type-check the expression. This also calls preEvaluate() to evaluate the function if all the arguments are constant; functions that do not require this behavior can override the preEvaluate method.
        Overrides:
        typeCheck in class FunctionCall
        Parameters:
        visitor - an expression visitor
        contextInfo - Information available statically about the context item: whether it is (possibly) absent; its static type; its streaming posture.
        Returns:
        the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
        Throws:
        XPathException - if an error is discovered during this phase (typically a type error)

      • optimize

        public Expression optimize​(ExpressionVisitor visitor,
                           ContextItemStaticInfo contextItemType)
                    throws XPathException
        Description copied from class: FunctionCall
        Perform optimisation of an expression and its subexpressions.

        This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.

        Overrides:
        optimize in class FunctionCall
        Parameters:
        visitor - an expression visitor
        contextItemType - the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set to Type.ITEM_TYPE
        Returns:
        the original expression, rewritten if appropriate to optimize execution
        Throws:
        XPathException - if an error is discovered during this phase (typically a type error)

      • resetLocalStaticProperties

        public void resetLocalStaticProperties()
        Reset the static properties of the expression to -1, so that they have to be recomputed next time they are used.
        Overrides:
        resetLocalStaticProperties in class Expression

      • addToPathMap

        public PathMap.PathMapNodeSet addToPathMap​(PathMap pathMap,
                                           PathMap.PathMapNodeSet pathMapNodeSet)
        Add a representation of this expression to a PathMap. The PathMap captures a map of the nodes visited by an expression in a source tree.

        The default implementation of this method assumes that an expression does no navigation other than the navigation done by evaluating its subexpressions, and that the subexpressions are evaluated in the same context as the containing expression. The method must be overridden for any expression where these assumptions do not hold. For example, implementations exist for AxisExpression, ParentExpression, and RootExpression (because they perform navigation), and for the doc(), document(), and collection() functions because they create a new navigation root. Implementations also exist for PathExpression and FilterExpression because they have subexpressions that are evaluated in a different context from the calling expression.

        Overrides:
        addToPathMap in class Expression
        Parameters:
        pathMap - the PathMap to which the expression should be added
        pathMapNodeSet - the PathMapNodeSet to which the paths embodied in this expression should be added
        Returns:
        the pathMapNode representing the focus established by this expression, in the case where this expression is the first operand of a path expression or filter expression. For an expression that does navigation, it represents the end of the arc in the path map that describes the navigation route. For other expressions, it is the same as the input pathMapNode.

      • markTailFunctionCalls

        public int markTailFunctionCalls​(StructuredQName qName,
                                 int arity)
        Mark tail-recursive calls on stylesheet functions. This marks the function call as tailRecursive if if is a call to the containing function, and in this case it also returns "true" to the caller to indicate that a tail call was found.
        Overrides:
        markTailFunctionCalls in class Expression
        Parameters:
        qName - the name of the function
        arity - the arity (number of parameters) of the function
        Returns:
        NOT_TAIL_CALL if no tail call was found; FOREIGN_TAIL_CALL if a tail call on a different function was found; SELF_TAIL_CALL if a tail recursive call was found and if this call accounts for the whole of the value.

      • evaluateItem

        public Item evaluateItem​(XPathContext c)
                  throws XPathException
        Call the function, returning the value as an item. This method will be used only when the cardinality is zero or one. If the function is tail recursive, it returns an Object representing the arguments to the next (recursive) call
        Overrides:
        evaluateItem in class Expression
        Parameters:
        c - The context in which the expression is to be evaluated
        Returns:
        the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence
        Throws:
        XPathException - if any dynamic error occurs evaluating the expression

      • iterate

        public SequenceIterator iterate​(XPathContext c)
                         throws XPathException
        Call the function, returning an iterator over the results. (But if the function is tail recursive, it returns an iterator over the arguments of the recursive call)
        Overrides:
        iterate in class FunctionCall
        Parameters:
        c - supplies the context for evaluation
        Returns:
        a SequenceIterator that can be used to iterate over the result of the expression
        Throws:
        XPathException - if any dynamic error occurs evaluating the expression

      • evaluatePendingUpdates

        public void evaluatePendingUpdates​(XPathContext context,
                                   PendingUpdateList pul)
                            throws XPathException
        Evaluate an updating expression, adding the results to a Pending Update List. The default implementation of this method, which is used for non-updating expressions, throws an UnsupportedOperationException
        Overrides:
        evaluatePendingUpdates in class Expression
        Parameters:
        context - the XPath dynamic evaluation context
        pul - the pending update list to which the results should be written
        Throws:
        XPathException - if evaluation fails

      • export

        public void export​(ExpressionPresenter out)
            throws XPathException
        Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
        Specified by:
        export in interface ExportAgent
        Overrides:
        export in class FunctionCall
        Parameters:
        out - the expression presenter used to display the structure
        Throws:
        XPathException - if the export fails, for example if an expression is found that won't work in the target environment.

      • getExpressionName

        public java.lang.String getExpressionName()
        Get a name identifying the kind of expression, in terms meaningful to a user.
        Overrides:
        getExpressionName in class FunctionCall
        Returns:
        a name identifying the kind of expression, in terms meaningful to a user. The name will always be in the form of a lexical XML QName, and should match the name used in explain() output displaying the expression.

      • getProperty

        public java.lang.Object getProperty​(java.lang.String name)
        Overrides:
        getProperty in class Expression

      • getObjectName

        public StructuredQName getObjectName()
        Description copied from interface: Traceable
        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 Traceable
        Overrides:
        getObjectName in class Expression
        Returns:
        the QName of the object declared or manipulated by this instruction or expression