Class CloneHelper

java.lang.Object
net.sf.jsqlparser.util.cnfexpression.CloneHelper

class CloneHelper extends Object
This class is mainly used for handling the cloning of an expression tree. Note this is the shallow copy of the tree. That means I do not modify or copy the expression other than these expressions: AND, OR, NOT, (), MULTI-AND, MULTI-OR. Since the CNF conversion only change the condition part of the tree.
  • Constructor Details

    • CloneHelper

      CloneHelper()
  • Method Details

    • modify

      public static Expression modify(Expression express)
    • shallowCopy

      public static Expression shallowCopy(Expression express)
      This method is used to copy the expression which happens at step four. I only copy the conditional expressions since the CNF only changes the conditional part.
      Parameters:
      express - the expression that will be copied.
      Returns:
      the copied expression.
    • changeBack

      public static Expression changeBack(Boolean isMultiOr, Expression exp)
      This helper method is used to change the multiple expression into the binary form, respectively and return the root of the expression tree.
      Parameters:
      isMultiOr - variable tells whether the expression is or.
      exp - the expression that needs to be converted.
      Returns:
      the root of the expression tree.