Class FunctionCall

    • Field Detail

      • argument

        protected Expression[] argument
        The array of expressions representing the actual parameters to the function call
    • Constructor Detail

      • FunctionCall

        public FunctionCall()
    • Method Detail

      • setFunctionNameCode

        public final void setFunctionNameCode​(int nc)
        Set the name code of the function being called
      • getFunctionNameCode

        public final int getFunctionNameCode()
        Get the name code of the function being called
        Returns:
        the name code as recorded in the name pool
      • getNumberOfArguments

        public final int getNumberOfArguments()
        Determine the number of actual arguments supplied in the function call
      • setArguments

        public void setArguments​(Expression[] args)
        Method called by the expression parser when all arguments have been supplied
      • getArguments

        public Expression[] getArguments()
        Get the expressions supplied as actual arguments to the function
      • simplifyArguments

        protected final Expression simplifyArguments​(StaticContext env)
                                              throws XPathException
        Simplify the arguments of the function. Called from the simplify() method of each function.
        Returns:
        the result of simplifying the arguments of the expression
        Throws:
        XPathException
      • typeCheck

        public Expression typeCheck​(StaticContext env,
                                    ItemType contextItemType)
                             throws XPathException
        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.
        Parameters:
        env - the static context of the expression
        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 to perform necessary run-time type checks, and to perform other type-related optimizations
        Throws:
        StaticError - if an error is discovered during this phase (typically a type error)
        XPathException
      • optimize

        public Expression optimize​(Optimizer opt,
                                   StaticContext env,
                                   ItemType contextItemType)
                            throws XPathException
        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.

        Parameters:
        opt - the optimizer in use. This provides access to supporting functions; it also allows different optimization strategies to be used in different circumstances.
        env - the static context of the expression
        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:
        StaticError - if an error is discovered during this phase (typically a type error)
        XPathException
      • preEvaluate

        public Expression preEvaluate​(StaticContext env)
                               throws XPathException
        Pre-evaluate a function at compile time. Functions that do not allow pre-evaluation, or that need access to context information, can override this method.
        Throws:
        XPathException
      • promote

        public Expression promote​(PromotionOffer offer)
                           throws XPathException
        Promote this expression if possible
        Specified by:
        promote in interface Expression
        Overrides:
        promote in class ComputedExpression
        Parameters:
        offer - details of the offer, for example the offer to move expressions that don't depend on the context to an outer level in the containing expression
        Returns:
        if the offer is not accepted, return this expression unchanged. Otherwise return the result of rewriting the expression to promote this subexpression
        Throws:
        XPathException - if any error is detected
      • checkArguments

        protected abstract void checkArguments​(StaticContext env)
                                        throws XPathException
        Method supplied by each class of function to check arguments during parsing, when all the argument expressions have been read
        Throws:
        XPathException
      • checkArgumentCount

        protected int checkArgumentCount​(int min,
                                         int max,
                                         StaticContext env)
                                  throws XPathException
        Check number of arguments.
        A convenience routine for use in subclasses.
        Parameters:
        min - the minimum number of arguments allowed
        max - the maximum number of arguments allowed
        Returns:
        the actual number of arguments
        Throws:
        XPathException - if the number of arguments is out of range
      • replaceSubExpression

        public boolean replaceSubExpression​(Expression original,
                                            Expression replacement)
        Replace one subexpression by a replacement subexpression
        Specified by:
        replaceSubExpression in interface Container
        Overrides:
        replaceSubExpression in class ComputedExpression
        Parameters:
        original - the original subexpression
        replacement - the replacement subexpression
        Returns:
        true if the original subexpression is found
      • getDisplayName

        public final java.lang.String getDisplayName​(NamePool pool)
        Diagnostic print of expression structure
      • display

        public void display​(int level,
                            java.io.PrintStream out,
                            Configuration config)
        Description copied from interface: Expression
        Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
        Parameters:
        level - indentation level for this expression
        out - Output destination