net.sf.saxon.expr.instruct
Interface DivisibleInstruction

All Known Implementing Classes:

ComputedElement, Copy, DocumentInstr, ElementCreator, FixedElement, ParentNodeConstructor, ResultDocument

public interface DivisibleInstruction

This interface is implemented by instructions that can be executed in streaming mode. The instruction offers two methods, processLeft() which is executed before processing the descendants of the context node, and processRight() which is executed after processing the descendants.

Method Summary

Expression	getContentExpression() Get the content expression
void	processLeft(Stack<XPathContext> contextStack, Stack<Object> state) In streaming mode, process the first half of the instruction (for example, to start a new document or element)
void	processRight(Stack<XPathContext> contextStack, Stack<Object> state) In streaming mode, process the right half of the instruction (for example, to end a new document or element)

Method Detail

processLeft

void processLeft(Stack<XPathContext> contextStack,
                 Stack<Object> state)
                 throws XPathException

In streaming mode, process the first half of the instruction (for example, to start a new document or element)

Parameters:

contextStack - Stack of XPathContext objects. The instruction should use the one at the top of the stack. Some instructions (such as xsl:result-document) create a new context object and add it to the stack, removing it in the corresponding processRight() action.

state - a stack on which the instruction can save state information during the call on processLeft(). state (together withe the contextStack) represents the "continuation", the data maintained by the instruction

Throws:

XPathException - if a dynamic error occurs

processRight

void processRight(Stack<XPathContext> contextStack,
                  Stack<Object> state)
                  throws XPathException

In streaming mode, process the right half of the instruction (for example, to end a new document or element)

Parameters:

contextStack - Stack of XPathContext objects. The instruction should use the one at the top of the stack.

state - the stack on which the instruction saved state information during the corresponding call on processLeft(). On entry to the processRight() method, the stack will be in the same state as it was on exit from processLeft().

Throws:

XPathException - if a dynamic error occurs

getContentExpression

Expression getContentExpression()

Get the content expression

Returns:

the expression that generates the content of the element or document node constructed by this DivisibleInstruction