net.sf.saxon.instruct

Class Bindery


public final class Bindery
extends java.lang.Object

The Bindery class holds information about variables and their values. From Saxon 8.1, it is used only for global variables: local variables are now held in the XPathContext object. Variables are identified by a Binding object. Values will always be of class Value.

Method Summary

void
allocateGlobals(SlotManager map)
Define how many slots are needed for global variables
void
assignGlobalVariable(GlobalVariable binding, ValueRepresentation value)
Assign a new value to a global variable.
void
defineGlobalParameters(GlobalParameterSet params)
Define global parameters
void
defineGlobalVariable(GlobalVariable binding, ValueRepresentation value)
Provide a value for a global variable
ValueRepresentation
getGlobalVariable(int slot)
Get the value of a global variable whose slot number is known
SlotManager
getGlobalVariableMap()
Get the Global Variable Map, containing the mapping of variable names (fingerprints) to slot numbers.
ValueRepresentation
getGlobalVariableValue(GlobalVariable binding)
Get the value of a global variable
ValueRepresentation[]
getGlobalVariables()
Get all the global variables, as an array.
void
setExecuting(GlobalVariable binding, boolean executing)
Set/Unset a flag to indicate that a particular global variable is currently being evaluated.
void
setGlobalVariable(int slot, ValueRepresentation value)
Set the value of a global variable whose slot number is known
boolean
useGlobalParameter(StructuredQName qName, int slot, SequenceType requiredType, XPathContext context)
Use global parameter.

Method Details

allocateGlobals

public void allocateGlobals(SlotManager map)
Define how many slots are needed for global variables
Parameters:
map - the SlotManager that keeps track of slot allocation for global variables.

assignGlobalVariable

public void assignGlobalVariable(GlobalVariable binding,
                                 ValueRepresentation value)
Assign a new value to a global variable. Supports saxon:assign.
Parameters:
binding - identifies the global variable or parameter
value - the value to be assigned to the variable

defineGlobalParameters

public void defineGlobalParameters(GlobalParameterSet params)
Define global parameters
Parameters:
params - The ParameterSet passed in by the user, eg. from the command line

defineGlobalVariable

public void defineGlobalVariable(GlobalVariable binding,
                                 ValueRepresentation value)
Provide a value for a global variable
Parameters:
binding - identifies the variable
value - the value of the variable

getGlobalVariable

public ValueRepresentation getGlobalVariable(int slot)
Get the value of a global variable whose slot number is known
Parameters:
slot - the slot number of the required variable
Returns:
the Value of the variable if defined, null otherwise.

getGlobalVariableMap

public SlotManager getGlobalVariableMap()
Get the Global Variable Map, containing the mapping of variable names (fingerprints) to slot numbers. This is provided for use by debuggers.
Returns:
the SlotManager containing information about the assignment of slot numbers to global variables and parameters

getGlobalVariableValue

public ValueRepresentation getGlobalVariableValue(GlobalVariable binding)
Get the value of a global variable
Parameters:
binding - the Binding that establishes the unique instance of the variable
Returns:
the Value of the variable if defined, null otherwise.

getGlobalVariables

public ValueRepresentation[] getGlobalVariables()
Get all the global variables, as an array. This is provided for use by debuggers that know the layout of the global variables within the array.
Returns:
the array of global varaibles.

setExecuting

public void setExecuting(GlobalVariable binding,
                         boolean executing)
            throws XPathException
Set/Unset a flag to indicate that a particular global variable is currently being evaluated.
Parameters:
binding - the global variable in question
executing - true when we start evaluating the variable, false when evaluation has finished
Throws:
XPathException - If an attempt is made to set the flag when it is already set, this means the definition of the variable is circular.

setGlobalVariable

public void setGlobalVariable(int slot,
                              ValueRepresentation value)
Set the value of a global variable whose slot number is known
Parameters:
slot - the slot number of the required variable
value - the Value of the variable if defined, null otherwise.

useGlobalParameter

public boolean useGlobalParameter(StructuredQName qName,
                                  int slot,
                                  SequenceType requiredType,
                                  XPathContext context)
            throws XPathException
Use global parameter. This is called when a global xsl:param element is processed. If a parameter of the relevant name was supplied, it is bound to the xsl:param element. Otherwise the method returns false, so the xsl:param default will be evaluated.
Parameters:
qName - The name of the parameter
slot - The slot number allocated to the parameter
requiredType - The declared type of the parameter
context - the XPath dynamic evaluation context
Returns:
true if a parameter of this name was supplied, false if not