Field Detail

• EVALUATE

  public static final int EVALUATE

  See Also:

  Constant Field Values

• EXPRESSION

  public static final int EXPRESSION

  See Also:

  Constant Field Values

• EVAL

  public static final int EVAL

  See Also:

  Constant Field Values

• EVALUATE_NODE

  public static final int EVALUATE_NODE

  See Also:

  Constant Field Values

Constructor Detail

• Evaluate

  public Evaluate​()

Method Detail

• getRequiredType

  protected SequenceType getRequiredType​(int arg)

  Get the required type of the nth argument

  Overrides:

  getRequiredType in class SystemFunction

  Parameters:

  arg - the number of the argument whose type is requested, zero-based

  Returns:

  the required type of the argument as defined in the function signature

• checkArguments

  public void checkArguments​(ExpressionVisitor visitor)
                      throws XPathException

  Method supplied by each class of function to check arguments during parsing, when all the argument expressions have been read

  Overrides:

  checkArguments in class SystemFunction

  Parameters:

  visitor - the expression visitor

  Throws:

  XPathException

• preEvaluate

  public Expression preEvaluate​(ExpressionVisitor visitor)
                         throws XPathException

  preEvaluate: for saxon:expression, if the expression is known at compile time, then it is compiled at compile time. In other cases this method suppresses compile-time evaluation by doing nothing (because the value of the expression depends on the runtime context).

  Overrides:

  preEvaluate in class FunctionCall

  Parameters:

  visitor - an expression visitor

  Returns:

  the result of the early evaluation, or the original expression, or potentially a simplified expression

  Throws:

  XPathException

• addToPathMap

  public PathMap.PathMapNodeSet addToPathMap​(PathMap pathMap,
                                             PathMap.PathMapNodeSet pathMapNodeSet)

  Add a representation of this expression to a PathMap. The PathMap captures a map of the nodes visited by an expression in a source tree.

  The default implementation of this method assumes that an expression does no navigation other than the navigation done by evaluating its subexpressions, and that the subexpressions are evaluated in the same context as the containing expression. The method must be overridden for any expression where these assumptions do not hold. For example, implementations exist for AxisExpression, ParentExpression, and RootExpression (because they perform navigation), and for the doc(), document(), and collection() functions because they create a new navigation root. Implementations also exist for PathExpression and FilterExpression because they have subexpressions that are evaluated in a different context from the calling expression.

  This particular implementation has to deal with the fact that saxon:evaluate() and related functions can navigate anywhere in the tree.

  Overrides:

  addToPathMap in class Expression

  Parameters:

  pathMap - the PathMap to which the expression should be added

  pathMapNodeSet - the PathMapNodeSet to which the paths embodied in this expression should be added

  Returns:

  the pathMapNodeSet representing the points in the source document that are both reachable by this expression, and that represent possible results of this expression. For an expression that does navigation, it represents the end of the arc in the path map that describes the navigation route. For other expressions, it is the same as the input pathMapNode.

• evaluateItem

  public Item evaluateItem​(XPathContext c)
                    throws XPathException

  Evaluate in a general context

  Specified by:

  evaluateItem in interface EvaluableItem

  Overrides:

  evaluateItem in class Expression

  Parameters:

  c - The context in which the expression is to be evaluated

  Returns:

  the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence

  Throws:

  XPathException - if any dynamic error occurs evaluating the expression

• iterate

  public SequenceIterator iterate​(XPathContext c)
                           throws XPathException

  Iterate over the results of the function

  Specified by:

  iterate in interface SequenceIterable

  Overrides:

  iterate in class Expression

  Parameters:

  c - supplies the context for evaluation

  Returns:

  a SequenceIterator that can be used to iterate over the result of the expression

  Throws:

  XPathException - if any dynamic error occurs evaluating the expression

• getIntrinsicDependencies

  public int getIntrinsicDependencies​()

  Determine the dependencies

  Overrides:

  getIntrinsicDependencies in class Expression

  Returns:

  a set of bit-significant flags identifying the "intrinsic" dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty