com.icl.saxon.expr
Class RootExpression
public class RootExpression
An expression whose value is always a set of nodes containing a single node, the document root.
containsReferences , display , enumerate , evaluate , evaluateAsBoolean , evaluateAsNodeSet , evaluateAsNumber , evaluateAsString , getDataType , getDependencies , getStaticContext , indent , isContextDocumentNodeSet , make , outputStringValue , reduce , setStaticContext , simplify , usesCurrent |
display
public void display(int level)
Diagnostic print of expression structure
- display in interface Expression
evaluateAsBoolean
public boolean evaluateAsBoolean(Context context)
throws XPathException
Evaluate as a boolean.
- evaluateAsBoolean in interface SingletonExpression
context
- The context (not used)
- true (always - because the nodeset is never empty)
evaluateAsString
public String evaluateAsString(Context context)
throws XPathException
Evaluate as a string
- evaluateAsString in interface SingletonExpression
context
- The context for evaluation
- The concatenation of all the character data within the document
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
- getDependencies in interface Expression
getNode
public NodeInfo getNode(Context context)
throws XPathException
Return the first element selected by this Expression
- getNode in interface SingletonExpression
context
- The evaluation context
- the NodeInfo of the first selected element, or null if no element
is selected
reduce
public Expression reduce(int dependencies,
Context context)
throws XPathException
Perform a partial evaluation of the expression, by eliminating specified dependencies
on the context.
- reduce in interface Expression
dependencies
- The dependencies to be removedcontext
- The context to be used for the partial evaluation
- a new expression that does not have any of the specified
dependencies