Package com.singularsys.jep.misc.nullwrapper.functions

Class NullWrappedLazyLogical

java.lang.Object
com.singularsys.jep.functions.PostfixMathCommand
com.singularsys.jep.misc.nullwrapper.functions.NullWrappedLazyLogical
All Implemented Interfaces:
CallbackEvaluationI, NullWrappedFunctionI, PostfixMathCommandI, Serializable
public class NullWrappedLazyLogical extends PostfixMathCommand implements CallbackEvaluationI, NullWrappedFunctionI
Null wrapped versions of the LazyLogical functions. In version 3.5 the convention has been changed to behave like the MySQL logical operators.
OR truth table
A OR B True False null
True True True True
False True False null
null True null null

 

AND truth table
A AND B True False null
True True False null
False False False False
null null False null

 

NOT truth table
A NOT A
True False
False True
null null
Since:
3.4
Version:
3.5
Author:
Richard Morris
See Also:

  • Field Details

    • AND

      public static final int AND
      See Also:

    • OR

      public static final int OR
      See Also:

    • id

      protected final int id
      Represents which logical operator this is.

    • allowNumbers

      protected boolean allowNumbers

  • Constructor Details

    • NullWrappedLazyLogical

      public NullWrappedLazyLogical(int id_in)
      Standard constructor, non-zero Numbers will be treated as true and zero Numbers as false.
      Parameters:
      id_in - either of the constants AND or OR

    • NullWrappedLazyLogical

      public NullWrappedLazyLogical(int id_in, boolean disallowNumbers)
      Constructor which restricts type of arguments.
      Parameters:
      id_in -
      disallowNumbers - if true Number arguments will raise exceptions, otherwise as the Standard constructor.

  • Method Details

    • getRoot

      public PostfixMathCommandI getRoot()
      Description copied from interface: NullWrappedFunctionI
      Get to function which this function wraps.
      Specified by:
      getRoot in interface NullWrappedFunctionI
      Returns:
      the root function, may be "this".

    • evaluate

      public Object evaluate(Node node, Evaluator pv) throws EvaluationException
      Description copied from interface: CallbackEvaluationI
      Performs some special evaluation on the node. This method has the responsibility for evaluating the children of the node, and it should generally call 
       pv.eval(node.jjtGetChild(i))
      for each child. The SymbolTable is not passed as an argument. This is because it is better practice to get and set variable values by using node.getVar().setValue() rather that through the SymbolTable with requires a hashtable lookup.
      Specified by:
      evaluate in interface CallbackEvaluationI
      Parameters:
      node - The current node
      pv - The visitor, can be used evaluate the children
      Returns:
      the value after evaluation. This value will be passed to other functions higher up the node tree. The value can be any type including Double or Vector<Object>
      Throws:
      EvaluationException - if the calculation cannot be performed
      See Also: