Class NotFn

All Implemented Interfaces:
Callable, FunctionItem, GroundedValue, Item, Sequence

public class NotFn extends SystemFunction
This class supports the XPath functions boolean(), not(), true(), and false()
  • Constructor Details

    • NotFn

      public NotFn()
  • Method Details

    • supplyTypeInformation

      public void supplyTypeInformation(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType, Expression[] arguments) throws XPathException
      Description copied from class: SystemFunction
      Method called during static type checking. This method may be implemented in subclasses so that functions can take advantage of knowledge of the types of the arguments that will be supplied.
      Overrides:
      supplyTypeInformation in class SystemFunction
      Parameters:
      visitor - an expression visitor, providing access to the static context and configuration
      contextItemType - information about whether the context item is set, and what its type is
      arguments - the expressions appearing as arguments in the function call
      Throws:
      XPathException - if an error is detected
    • call

      public BooleanValue call(XPathContext context, Sequence[] arguments) throws XPathException
      Evaluate the expression
      Parameters:
      context - the dynamic evaluation context
      arguments - the values of the arguments, supplied as Sequences
      Returns:
      the result of the evaluation, in the form of a Sequence
      Throws:
      XPathException - if a dynamic error occurs during the evaluation of the expression
    • makeFunctionCall

      public Expression makeFunctionCall(Expression[] arguments)
      Make an expression that either calls this function, or that is equivalent to a call on this function
      Overrides:
      makeFunctionCall in class SystemFunction
      Parameters:
      arguments - the supplied arguments to the function call
      Returns:
      either a function call on this function, or an expression that delivers the same result
    • makeOptimizedFunctionCall

      public Expression makeOptimizedFunctionCall(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo, Expression... arguments) throws XPathException
      Allow the function to create an optimized call based on the values of the actual arguments
      Overrides:
      makeOptimizedFunctionCall in class SystemFunction
      Parameters:
      visitor - the expression visitor
      contextInfo - information about the context item
      arguments - the supplied arguments to the function call
      Returns:
      either a function call on this function, or an expression that delivers the same result, or null indicating that no optimization has taken place
      Throws:
      XPathException - if an error is detected
    • getStreamerName

      public String getStreamerName()
      Description copied from class: SystemFunction
      Get a name that identifies the class that can be used to evaluate this function in streaming mode, that is, supplying one item or event at a time as it is delivered by the parser. Special streaming support is generally available in Saxon-EE for all system functions that take a sequence as their argument.
      Overrides:
      getStreamerName in class SystemFunction
      Returns:
      a name that identifies a class that supports streamed evaluation of this system function, or null if no such class is available. The mapping of names to classes is defined in the Saxon-EE class StreamerMap. In non-streaming Saxon editions (HE and PE) the method always returns null.
    • getElaborator

      public Elaborator getElaborator()
      Make an elaborator for a system function call on this function
      Overrides:
      getElaborator in class SystemFunction
      Returns:
      a suitable elaborator; or null if no custom elaborator is available