com.icl.saxon.functions
Class Key

java.lang.Object
  |
  +--com.icl.saxon.expr.Expression
        |
        +--com.icl.saxon.expr.Function
              |
              +--com.icl.saxon.functions.Key

public class Key
extends Function


Fields inherited from class com.icl.saxon.expr.Function
arguments
 
Fields inherited from class com.icl.saxon.expr.Expression
emptyVector, staticContext
 
Constructor Summary
Key()
           
 
Method Summary
 Value eval(java.util.Vector args, Context context)
          Evaluate the expression
 int getDataType()
          Determine the data type of the exprssion, if possible
 int getIntrinsicDependencies()
          Determine which aspects of the context the expression depends on.
 java.lang.String getName()
          Get the name of the function.
 Function newInstance()
          Make a new instance of this function
protected  Expression reduceIntrinsic(int dependencies, Context context)
          Remove intrinsic dependencies.
 
Methods inherited from class com.icl.saxon.expr.Function
addArgument, checkArgumentCount, evaluate, getDependencies, reduce, simplify, simplifyPureFunction, toString
 
Methods inherited from class com.icl.saxon.expr.Expression
containsReferences, enumerate, evaluateAsBoolean, evaluateAsNodeSet, evaluateAsNumber, evaluateAsString, getStaticContext, isNumeric, isRelative, make, make, setStaticContext, usesCurrent
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

Key

public Key()
Method Detail

getName

public java.lang.String getName()
Description copied from class: Function
Get the name of the function. This method must be implemented in all subclasses.
Overrides:
getName in class Function
Following copied from class: com.icl.saxon.expr.Function
Returns:
the name of the function, as used in XSL expressions, but excluding its namespace prefix

getDataType

public int getDataType()
Determine the data type of the exprssion, if possible
Overrides:
getDataType in class Expression
Returns:
Value.NODESET

getIntrinsicDependencies

public int getIntrinsicDependencies()
Determine which aspects of the context the expression depends on. The result is a bitwise-or'ed value composed from constants such as Context.VARIABLES and Context.CURRENT_NODE
Overrides:
getIntrinsicDependencies in class Function

reduceIntrinsic

protected Expression reduceIntrinsic(int dependencies,
                                     Context context)
                              throws org.xml.sax.SAXException
Remove intrinsic dependencies.
Overrides:
reduceIntrinsic in class Function

newInstance

public Function newInstance()
                     throws org.xml.sax.SAXException
Make a new instance of this function
Overrides:
newInstance in class Function

eval

public Value eval(java.util.Vector args,
                  Context context)
           throws org.xml.sax.SAXException
Evaluate the expression
Overrides:
eval in class Function
Following copied from class: com.icl.saxon.expr.Function
Parameters:
arguments - A Vector, each of whose elements is a Value containing the value of a supplied argument to the function.
context - The context in which the function is to be evaluated
Returns:
a Value representing the result of the function. This must be of the data type corresponding to the result of getType().
Throws:
org.xml.sax.SAXException - if the function cannot be evaluated.