Package org.apache.commons.jxpath.ri.compiler

Class CoreOperationRelationalExpression

java.lang.Object
org.apache.commons.jxpath.ri.compiler.Expression
org.apache.commons.jxpath.ri.compiler.Operation
org.apache.commons.jxpath.ri.compiler.CoreOperation
org.apache.commons.jxpath.ri.compiler.CoreOperationRelationalExpression
Direct Known Subclasses:
CoreOperationGreaterThan, CoreOperationGreaterThanOrEqual, CoreOperationLessThan, CoreOperationLessThanOrEqual
public abstract class CoreOperationRelationalExpression extends CoreOperation
Base implementation of Expression for the operations ">", ">=", "<", "<=".
Since:
JXPath 1.3
Version:
$Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $

  • Constructor Details

    • CoreOperationRelationalExpression

      protected CoreOperationRelationalExpression(Expression[] args)
      Create a new CoreOperationRelationalExpression.
      Parameters:
      args - arguments

  • Method Details

    • computeValue

      public final Object computeValue(EvalContext context)
      Description copied from class: Expression
      Evaluates the expression. If the result is a node set, returns the first element of the node set.
      Specified by:
      computeValue in class CoreOperation
      Parameters:
      context - evaluation context
      Returns:
      Object

    • getPrecedence

      protected final int getPrecedence()
      Description copied from class: CoreOperation
      Computes the precedence of the operation.
      Specified by:
      getPrecedence in class CoreOperation
      Returns:
      int precedence

    • isSymmetric

      protected final boolean isSymmetric()
      Description copied from class: CoreOperation
      Returns true if the operation is not sensitive to the order of arguments, e.g. "=", "and" etc, and false if it is, e.g. "<=", "div".
      Specified by:
      isSymmetric in class CoreOperation
      Returns:
      boolean

    • evaluateCompare

      protected abstract boolean evaluateCompare(int compare)
      Template method for subclasses to evaluate the result of a comparison.
      Parameters:
      compare - result of comparison to evaluate
      Returns:
      ultimate operation success/failure

    • compute

      private boolean compute(Object left, Object right)
      Compare left to right.
      Parameters:
      left - left operand
      right - right operand
      Returns:
      operation success/failure

    • reduce

      private Object reduce(Object o)
      Reduce an operand for comparison.
      Parameters:
      o - Object to reduce
      Returns:
      reduced operand

    • containsMatch

      private boolean containsMatch(Iterator it, Object value)
      Learn whether any element returned from an Iterator matches a given value.
      Parameters:
      it - Iterator
      value - to look for
      Returns:
      whether a match was found

    • findMatch

      private boolean findMatch(Iterator lit, Iterator rit)
      Learn whether there is an intersection between two Iterators.
      Parameters:
      lit - left Iterator
      rit - right Iterator
      Returns:
      whether a match was found