com.icl.saxon.expr
Class  PathExpression
java.lang.Object
  |
  +--com.icl.saxon.expr.Expression
        |
        +--com.icl.saxon.expr.NodeSetExpression
              |
              +--com.icl.saxon.expr.PathExpression
- public class PathExpression- extends NodeSetExpression
An expression that establishes a set of nodes by following relationships between nodes
 in the document. Specifically, it consists of a start expression which defines a set of
 nodes, and a Step which defines a relationship to be followed from those nodes to create
 a new set of nodes.
 
 
| Method Summary | 
|  NodeEnumeration | enumerate(Context context)Evaluate the path-expression in a given context to return a NodeSet
 | 
|  int | getDependencies()Determine which aspects of the context the expression depends on.
 | 
|  Expression | reduce(int dependencies,
       Context context)Perform a partial evaluation of the expression, by eliminating specified dependencies
 on the context.
 | 
|  Expression | simplify()Simplify an expression
 | 
|  java.lang.String | toString()Return a string representation of the expression
 Used for diagnostics, and also for reconstituting the expression in the compiler
 | 
 
 
 
| Methods inherited from class java.lang.Object | 
| clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait | 
 
PathExpression
public PathExpression(Expression start,
                      Step step)
- Constructor- 
- Parameters:
- start- A node-set expression denoting the absolute or relative set of nodes from which the
 navigation path should start.
- step- The step to be followed from each node in the start expression to yield a new
 node-set
 
simplify
public Expression simplify()
                    throws org.xml.sax.SAXException
- Simplify an expression- 
- Overrides:
- simplifyin class- Expression
 
- 
- Returns:
- the simplified expression
 
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:
- getDependenciesin class- Expression
 
reduce
public Expression reduce(int dependencies,
                         Context context)
                  throws org.xml.sax.SAXException
- Perform a partial evaluation of the expression, by eliminating specified dependencies
 on the context.- 
- Overrides:
- reducein 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
 
enumerate
public NodeEnumeration enumerate(Context context)
                          throws org.xml.sax.SAXException
- Evaluate the path-expression in a given context to return a NodeSet- 
- Overrides:
- enumeratein class- NodeSetExpression
 
- 
- Parameters:
- context- the evaluation context
 
toString
public java.lang.String toString()
- Return a string representation of the expression
 Used for diagnostics, and also for reconstituting the expression in the compiler- 
- Overrides:
- toStringin class- java.lang.Object