com.saxonica.codegen
Class IntegratedFunctionCompiler

java.lang.Object
  com.saxonica.codegen.IntegratedFunctionCompiler

Direct Known Subclasses:

IsWholeNumberCompiler, ItemAtCompiler

public abstract class IntegratedFunctionCompiler
extends Object

This abstract class represents the compiler (that is, Java code generator) for an integrated extension function appearing on the expression tree

Constructor Summary

IntegratedFunctionCompiler()

Method Summary

abstract String

compile(CompilerService compiler, ExtensionFunctionCall function, Expression[] arguments, String[] variables) Generate Java code to evaluate the expression as a SequenceIterator

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

IntegratedFunctionCompiler

public IntegratedFunctionCompiler()

Method Detail

compile

public abstract String compile(CompilerService compiler,
                               ExtensionFunctionCall function,
                               Expression[] arguments,
                               String[] variables)

Generate Java code to evaluate the expression as a SequenceIterator

Parameters:

compiler - the compiler service

function - the integrated function call to be compiled

arguments - the arguments supplied to the function call

variables - an array of strings each being the Java name of a variable that holds the value of the corresponding argument, either as a SequenceIterator in the case of an argument that allows more than one value, or as an Item if the argument only allows a singleton

Returns:

a simple Java expression (usually the name of a variable that has been declared). If the result type of the function is boolean, this variable will hold a Java boolean. If the result type is an optional item, it will hold an Item (using null to represent an empty sequence). If it is any other type, the variable will hold a SequenceIterator, In each case the Java variable will at run-time hold the value of the XPath expression