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: Class ContextNodeExpression

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com.icl.saxon.expr
Class ContextNodeExpression


java.lang.Object

  |

  +--com.icl.saxon.expr.Expression

        |

        +--com.icl.saxon.expr.NodeSetExpression

              |

              +--com.icl.saxon.expr.SingletonExpression

                    |

                    +--com.icl.saxon.expr.ContextNodeExpression

public final class ContextNodeExpression
extends SingletonExpression

This class represents the expression ".", which always returns the context node.

Fields inherited from class com.icl.saxon.expr.Expression

staticContext

Constructor Summary

ContextNodeExpression()


Method Summary

void display(int level)
          Diagnostic print of expression structure

int getDependencies()
          Determine which aspects of the context the expression depends on.

NodeInfo getNode(Context context)
          Return the node selected by this expression.

Expression reduce(int dependencies, Context context)
          Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.

Methods inherited from class com.icl.saxon.expr.SingletonExpression

enumerate, evaluateAsBoolean, evaluateAsNodeSet, evaluateAsString, isContextDocumentNodeSet, selectFirst

Methods inherited from class com.icl.saxon.expr.NodeSetExpression

evaluate, getDataType, outputStringValue

Methods inherited from class com.icl.saxon.expr.Expression

containsReferences, evaluateAsNumber, getStaticContext, indent, make, setStaticContext, simplify, usesCurrent

Methods inherited from class java.lang.Object

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

Constructor Detail

ContextNodeExpression


public ContextNodeExpression()

Method Detail

getNode


public NodeInfo getNode(Context context)
                 throws XPathException

Return the node selected by this expression.

Overrides:: getNode in class SingletonExpression

Parameters:: context - The context for the evaluation
Returns:: one NodeInfo only, namely the current node defined by the context

getDependencies


public int getDependencies()

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:: getDependencies in class Expression

reduce


public Expression reduce(int dependencies,
                         Context context)
                  throws XPathException

Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.

Overrides:: reduce in class Expression

Parameters:: dependencies - The dependencies to be removed; context - The context to be used for the partial evaluation
Returns:: a new expression that does not have any of the specified dependencies

display


public void display(int level)

Diagnostic print of expression structure

Overrides:: display in class Expression