net.sf.saxon.instruct

Class SlotManager

public class SlotManager extends Object implements Serializable

A SlotManager supports functions, templates, etc: specifically, any executable code that requires a stack frame containing local variables. In XSLT a SlotManager underpins any top-level element that can contain local variable declarations, specifically, a top-level xsl:template, xsl:variable, xsl:param, or xsl:function element or an xsl:attribute-set element or xsl:key element. In XQuery it underpins functions and global variables. The purpose of the SlotManager is to allocate slot numbers to variables in the stack, and to record how many slots are needed. A Debugger may define a subclass with additional functionality.
Field Summary
static SlotManagerEMPTY
An empty SlotManager
Constructor Summary
SlotManager()
The constructor should not be called directly.
SlotManager(int n)
Create a SlotManager with a given number of slots
Method Summary
intallocateSlotNumber(StructuredQName qName)
Allocate a slot number for a variable
intgetNumberOfVariables()
Get number of variables (size of stack frame)
List<StructuredQName>getVariableMap()
Get the variable map (simply a list of variable names as structured QNames).
voidsetNumberOfVariables(int numberOfVariables)
Set the number of variables

Field Detail

EMPTY

public static SlotManager EMPTY
An empty SlotManager

Constructor Detail

SlotManager

public SlotManager()
The constructor should not be called directly. A new SlotManager should be obtained using the factory method makeSlotManager.

SlotManager

public SlotManager(int n)
Create a SlotManager with a given number of slots

Method Detail

allocateSlotNumber

public int allocateSlotNumber(StructuredQName qName)
Allocate a slot number for a variable

getNumberOfVariables

public int getNumberOfVariables()
Get number of variables (size of stack frame)

getVariableMap

public List<StructuredQName> getVariableMap()
Get the variable map (simply a list of variable names as structured QNames). Note that it is possible for several variables to have the same name.

Changed in Saxon 9.0 to return a list of StructuredQName values rather than integers

setNumberOfVariables

public void setNumberOfVariables(int numberOfVariables)
Set the number of variables

Parameters: numberOfVariables