Class BooleanExpression


  • class BooleanExpression
    extends BinaryExpression
    Boolean expression: two booleans combined using AND or OR
    • Constructor Detail

      • BooleanExpression

        public BooleanExpression()
    • Method Detail

      • evaluate

        public Value evaluate​(Context c)
                       throws XPathException
        Description copied from class: Expression
        Evaluate an expression.
        Specified by:
        evaluate in class Expression
        Parameters:
        c - The context in which the expression is to be evaluated
        Returns:
        the value of the expression, evaluated in the current context
        Throws:
        XPathException
      • evaluateAsBoolean

        public boolean evaluateAsBoolean​(Context c)
                                  throws XPathException
        Description copied from class: Expression
        Evaluate an expression as a Boolean.
        The result of x.evaluateAsBoolean(c) must be equivalent to x.evaluate(c).asBoolean(); but optimisations are possible when it is known that a boolean result is required, especially in the case of a NodeSet.
        Overrides:
        evaluateAsBoolean in class Expression
        Parameters:
        c - The context in which the expression is to be evaluated
        Returns:
        the value of the expression, evaluated in the current context
        Throws:
        XPathException
      • getDataType

        public int getDataType()
        Determine the data type of the expression
        Specified by:
        getDataType in class Expression
        Returns:
        Value.BOOLEAN
      • reduce

        public Expression reduce​(int dependencies,
                                 Context context)
                          throws XPathException
        Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.
        Specified by:
        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
        Throws:
        XPathException