Package com.bpodgursky.jbool_expressions.rules

Class RuleSet

java.lang.Object

com.bpodgursky.jbool_expressions.rules.RuleSet

public class RuleSet
extends Object

Constructor Summary

Constructors

Constructor	Description
RuleSet()

Method Summary

Modifier and Type	Method	Description
static <K> Expression<K>	assign(Expression<K> root, Map<K,Boolean> values)
static <K> Expression<K>	assign(Expression<K> root, Map<K,Boolean> values, ExprOptions<K> options)
static <K> Expression<K>	simplify(Expression<K> root)
static <K> Expression<K>	simplify(Expression<K> root, ExprOptions<K> options)
static <K> Expression<K>	toCNF(Expression<K> root)
static <K> Expression<K>	toCNF(Expression<K> root, ExprOptions<K> options)	More formal name for product-of-sums
static <K> Expression<K>	toDNF(Expression<K> root)
static <K> Expression<K>	toDNF(Expression<K> root, ExprOptions<K> options)	More formal name for sum-of-products
static <K> Expression<K>	toDNFViaQMC(Expression<K> root, ExprOptions<K> options)	This method transforms an expression to DNF, but at a variable cardinality less than 9, switches to the QuineMcCluskey algorithm.
static <K> Expression<K>	toPos(Expression<K> root)
static <K> Expression<K>	toPos(Expression<K> root, ExprOptions<K> options)
static <K> Expression<K>	toSop(Expression<K> root)
static <K> Expression<K>	toSop(Expression<K> root, ExprOptions<K> options)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RuleSet

public RuleSet()

Method Detail

simplify

public static <K> Expression<K> simplify(Expression<K> root)

simplify

public static <K> Expression<K> simplify(Expression<K> root,
                                         ExprOptions<K> options)

toDNFViaQMC

public static <K> Expression<K> toDNFViaQMC(Expression<K> root,
                                            ExprOptions<K> options)

This method transforms an expression to DNF, but at a variable cardinality less than 9, switches to the QuineMcCluskey algorithm.

The problem with using the switch globally is that QMC can be considerably slower than "naiive" simplification on really simple expressions. For example, (A | B | C | D | E | F | G) takes 15ms using the standard toSop rules, but 120ms using QMC. But QMC is dramatically faster on some larger expressions with the same number of variables -- see https://github.com/bpodgursky/jbool_expressions/issues/29 for an example.

So for now, I'm going to add a new method instead of potentially introducing a performance regression on the old method. If there's a smarter way to "guess" which method would be faster on a given expression, I'm happy to use it, but nothing comes to mind.

toSop

public static <K> Expression<K> toSop(Expression<K> root)

toSop

public static <K> Expression<K> toSop(Expression<K> root,
                                      ExprOptions<K> options)

toPos

public static <K> Expression<K> toPos(Expression<K> root)

toPos

public static <K> Expression<K> toPos(Expression<K> root,
                                      ExprOptions<K> options)

assign

public static <K> Expression<K> assign(Expression<K> root,
                                       Map<K,Boolean> values)

assign

public static <K> Expression<K> assign(Expression<K> root,
                                       Map<K,Boolean> values,
                                       ExprOptions<K> options)

toDNF

public static <K> Expression<K> toDNF(Expression<K> root,
                                      ExprOptions<K> options)

More formal name for sum-of-products

toDNF

public static <K> Expression<K> toDNF(Expression<K> root)

toCNF

public static <K> Expression<K> toCNF(Expression<K> root,
                                      ExprOptions<K> options)

More formal name for product-of-sums

toCNF

public static <K> Expression<K> toCNF(Expression<K> root)