Class CNFRule

java.lang.Object
  CNFRule

public class CNFRule
extends java.lang.Object

Version:

Fall 2007 There are three types of rules allowed in a CNF grammar, which we will refer to as "type 0", "type 1", and "type 2". Type 0 transforms a variable to a pair of variables, type 1 transforms a variable to a terminal symbol, and type 2 transforms the start variable to the empty string. The CNFRule class is used to represent instances of rules of type 0 or 1. Data Fields: A CNFRule has a "type" (integer code 0 or 1), three integer variables "var1", "var2", "var3", and a char variable "term" (terminal symbol). Type 0 rules are form vn -> vi vj where i and j are non-zero. In this case, type = 0, var1 = n, var2 = i, var3 = j, and "term" is irrelevant. Type 1 rules are form vn -> t. In this case, type = 1, var1 = n, term = t, and "var2", "var3" are irrelevant. Methods: CNFRule class has the usual accessor methods plus an "equals" method.

Author:

Barbara Wahl

Constructor Summary

CNFRule(CNFRule current)

CNFRule(int n, char t)

CNFRule(int n, int i, int j)
3-arg constructor for type 0 rule, "vn -> vi vj"

Method Summary

boolean	equals(java.lang.Object other)
static void	main(java.lang.String[] args)
char	term()
java.lang.String	toString()
int	type()
int	var1()
int	var2()
int	var3()

Methods inherited from class java.lang.Object

getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

CNFRule

public CNFRule(int n,
               int i,
               int j)

3-arg constructor for type 0 rule, "vn -> vi vj"

Precondition:

0<=n, 0

Postcondition:

type = 0, var1 = n, var2 = i, var3 = j, term = '-'

CNFRule

public CNFRule(int n,
               char t)

CNFRule

public CNFRule(CNFRule current)

Method Detail

type

public int type()

var1

public int var1()

var2

public int var2()

var3

public int var3()

term

public char term()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.Object other)

Overrides:

equals in class java.lang.Object

main

public static void main(java.lang.String[] args)