Package org.apache.xpath.operations

Class Operation

java.lang.Object
org.apache.xpath.Expression
org.apache.xpath.operations.Operation
All Implemented Interfaces:
Serializable, SourceLocator, ExpressionNode, ExpressionOwner, XPathVisitable
Direct Known Subclasses:
And, Div, Equals, Gt, Gte, Lt, Lte, Minus, Mod, Mult, NotEquals, Or, Plus, Quo
public class Operation
extends Expression
implements ExpressionOwner
The baseclass for a binary operation.
See Also:
Serialized Form

  • Field Details

    • m_left

      protected Expression m_left
      The left operand expression.

    • m_right

      protected Expression m_right
      The right operand expression.

  • Constructor Details

    • Operation

      public Operation()

  • Method Details

    • fixupVariables

      public void fixupVariables​(Vector vars, int globalsSize)
      This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.
      Specified by:
      fixupVariables in class Expression
      Parameters:
      vars - List of QNames that correspond to variables. This list should be searched backwards for the first qualified name that corresponds to the variable reference qname. The position of the QName in the vector from the start of the vector will be its position in the stack frame (but variables above the globalsTop value will need to be offset to the current stack frame).

    • canTraverseOutsideSubtree

      public boolean canTraverseOutsideSubtree()
      Tell if this expression or it's subexpressions can traverse outside the current subtree.
      Overrides:
      canTraverseOutsideSubtree in class Expression
      Returns:
      true if traversal outside the context node's subtree can occur.

    • setLeftRight

      public void setLeftRight​(Expression l, Expression r)
      Set the left and right operand expressions for this operation.
      Parameters:
      l - The left expression operand.
      r - The right expression operand.

    • execute

      public XObject execute​(XPathContext xctxt) throws TransformerException
      Execute a binary operation by calling execute on each of the operands, and then calling the operate method on the derived class.
      Specified by:
      execute in class Expression
      Parameters:
      xctxt - The runtime execution context.
      Returns:
      The XObject result of the operation.
      Throws:
      TransformerException

    • operate

      public XObject operate​(XObject left, XObject right) throws TransformerException
      Apply the operation to two operands, and return the result.
      Parameters:
      left - non-null reference to the evaluated left operand.
      right - non-null reference to the evaluated right operand.
      Returns:
      non-null reference to the XObject that represents the result of the operation.
      Throws:
      TransformerException

    • getLeftOperand

      public Expression getLeftOperand()
      Returns:
      the left operand of binary operation, as an Expression.

    • getRightOperand

      public Expression getRightOperand()
      Returns:
      the right operand of binary operation, as an Expression.

    • callVisitors

      public void callVisitors​(ExpressionOwner owner, XPathVisitor visitor)
      Description copied from interface: XPathVisitable
      This will traverse the heararchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called.
      Specified by:
      callVisitors in interface XPathVisitable
      Parameters:
      owner - The owner of the visitor, where that path may be rewritten if needed.
      visitor - The visitor whose appropriate method will be called.
      See Also:
      XPathVisitable.callVisitors(ExpressionOwner, XPathVisitor)

    • getExpression

      public Expression getExpression()
      Description copied from interface: ExpressionOwner
      Get the raw Expression object that this class wraps.
      Specified by:
      getExpression in interface ExpressionOwner
      Returns:
      the raw Expression object, which should not normally be null.
      See Also:
      ExpressionOwner.getExpression()

    • setExpression

      public void setExpression​(Expression exp)
      Description copied from interface: ExpressionOwner
      Set the raw expression object for this object.
      Specified by:
      setExpression in interface ExpressionOwner
      Parameters:
      exp - the raw Expression object, which should not normally be null.
      See Also:
      ExpressionOwner.setExpression(Expression)

    • deepEquals

      public boolean deepEquals​(Expression expr)
      Description copied from class: Expression
      Compare this object with another object and see if they are equal, include the sub heararchy.
      Specified by:
      deepEquals in class Expression
      Parameters:
      expr - Another expression object.
      Returns:
      true if this objects class and the expr object's class are the same, and the data contained within both objects are considered equal.
      See Also:
      Expression.deepEquals(Expression)