XorInvariantsVisitor

Object
- DepthFirstVisitor
- - PrintAllVisitor
  - - PrintDifferingInvariantsVisitor
    - - XorInvariantsVisitor

All Implemented Interfaces:

Visitor
```
public class XorInvariantsVisitor
extends PrintDifferingInvariantsVisitor
```
XorInvariantsVisitor is a visitor that performs a standard Diff on two PptMaps, that is, finds the set of Invariants in the XOR set of two PptMaps. However, while those XOR Invariants were the end product of standard diff, this visitor is useful when the XOR set is a means to an end, since you get back a data structure containing the XOR set.
Currently, this visitor actually modifies the first of the two PptMaps. This might be an undesirable design call, but creating a PptMap from scratch is difficult given the constraining creational pattern in place.

Field Summary
- Fields inherited from class PrintDifferingInvariantsVisitor
  debug
- Fields inherited from class PrintAllVisitor
  HUMAN_OUTPUT, lineSep

Constructor Summary

Constructors
Constructor	Description
`XorInvariantsVisitor(PrintStream ps, boolean verbose, boolean printEmptyPpts)`	Create an instance of XorInvariantsVisitor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected boolean`	`shouldPrint(@Nullable Invariant inv1, @Nullable Invariant inv2)`	Returns true if the pair of invariants should be printed, depending on their type, relationship, and printability.
`void`	`visit(InvNode node)`	Prints a pair of invariants.
`void`	`visit(PptNode node)`	Prints the pair of program points, and all the invariants contained within them.

Methods inherited from class PrintAllVisitor
bufPrint, bufPrintln, bufPrintln, printHumanOutput, printInvariant

Methods inherited from class DepthFirstVisitor
visit

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - XorInvariantsVisitor
```
public XorInvariantsVisitor(PrintStream ps,
                            boolean verbose,
                            boolean printEmptyPpts)
```
    Create an instance of XorInvariantsVisitor.
- Method Detail
  - visit
```
public void visit(PptNode node)
```
    Description copied from class: PrintAllVisitor
    
    Prints the pair of program points, and all the invariants contained within them.
    
    Specified by:
    
    visit in interface Visitor
    
    Overrides:
    
    visit in class PrintAllVisitor
  - visit
```
public void visit(InvNode node)
```
    Description copied from class: PrintAllVisitor
    
    Prints a pair of invariants. Includes the type of the invariants and their relationship.
    
    Specified by:
    
    visit in interface Visitor
    
    Overrides:
    
    visit in class PrintDifferingInvariantsVisitor
  - shouldPrint
```
protected boolean shouldPrint(@Nullable Invariant inv1,
                              @Nullable Invariant inv2)
```
    Returns true if the pair of invariants should be printed, depending on their type, relationship, and printability.
    
    Overrides:
    
    shouldPrint in class PrintDifferingInvariantsVisitor