Class RelationalExpression


final class RelationalExpression extends BinaryExpression
Relational Expression: a boolean expression that compares two expressions for equals, not-equals, greater-than or less-than.
  • Constructor Details

    • RelationalExpression

      public RelationalExpression()
      Default constructor
    • RelationalExpression

      public RelationalExpression(Expression p1, int op, Expression p2)
      Create a relational expression identifying the two operands and the operator
      Parameters:
      p1 - the left-hand operand
      op - the operator, as a token returned by the Tokenizer (e.g. Tokenizer.LT)
      p2 - the right-hand operand
  • Method Details

    • simplify

      public Expression simplify() throws XPathException
      Simplify an expression
      Overrides:
      simplify in class BinaryExpression
      Returns:
      the simplified expression
      Throws:
      XPathException
    • evaluate

      public Value evaluate(Context c) throws XPathException
      Evaluate the expression in a given context
      Specified by:
      evaluate in class Expression
      Parameters:
      c - the given context for evaluation
      Returns:
      a BooleanValue representing the result of the numeric comparison of the two operands
      Throws:
      XPathException
    • evaluateAsBoolean

      public boolean evaluateAsBoolean(Context c) throws XPathException
      Evaluate the expression in a given context
      Overrides:
      evaluateAsBoolean in class Expression
      Parameters:
      c - the given context for evaluation
      Returns:
      a boolean representing the result of the numeric comparison of the two operands
      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