ec.rule
Class Rule

java.lang.Object
  extended by ec.rule.Rule
All Implemented Interfaces:
Prototype, Setup, java.io.Serializable, java.lang.Cloneable, java.lang.Comparable

public abstract class Rule
extends java.lang.Object
implements Prototype, java.lang.Comparable

Rule is an abstract class for describing rules. It is abstract because it is supposed to be extended by different classes modelling different kinds of rules. It provides the reset abstract method for randomizing the individual. It also provides the mutate function for mutating an individual rule It also provides the clone function for cloning the rule.

You will need to implement some kind of artificial ordering between rules in a ruleset using the Comparable interface, so the ruleset can be sorted in such a way that it can be compared with another ruleset for equality. You should also implement hashCode and equals in such a way that they aren't based on pointer information, but on actual internal features.

Every rule points to a RuleConstraints which handles information that Rule shares with all the other Rules in a RuleSet.

In addition to serialization for checkpointing, Rules may read and write themselves to streams in three ways.

Parameters

base.constraints
string
(name of the rule constraint)

Default Base
rule.rule

Version:
1.0
Author:
Liviu Panait and Sean luke
See Also:
Serialized Form

Field Summary
 byte constraints
          An index to a RuleConstraints
static java.lang.String P_CONSTRAINTS
           
static java.lang.String P_RULE
           
 
Constructor Summary
Rule()
           
 
Method Summary
 java.lang.Object clone()
          Creates a new individual cloned from a prototype, and suitable to begin use in its own evolutionary context.
abstract  int compareTo(java.lang.Object o)
          This function replaces the old gt and lt functions that Rule used to require as it implemented the SortComparator interface.
 RuleConstraints constraints(RuleInitializer initializer)
           
 Parameter defaultBase()
          Returns the default base for this prototype.
abstract  boolean equals(java.lang.Object other)
          Unlike the standard form for Java, this function should return true if this rule is "genetically identical" to the other rule.
abstract  int hashCode()
          Rulerates a hash code for this rule -- the rule for this is that the hash code must be the same for two rules that are equal to each other genetically.
 void mutate(EvolutionState state, int thread)
          Mutate the rule.
 void printRule(EvolutionState state, int log, int verbosity)
          Prints the rule in a way that can be read by readRule().
 void printRule(EvolutionState state, java.io.PrintWriter writer)
          Prints the rule in a way that can be read by readRule().
 void printRuleForHumans(EvolutionState state, int log, int verbosity)
          Nice printing.
 java.lang.String printRuleToString()
          Prints the rule to a string in a fashion readable by readRuleFromString.
 java.lang.String printRuleToString(EvolutionState state)
          Deprecated.  
 java.lang.String printRuleToStringForHumans()
          Nice printing to a string.
 void readRule(EvolutionState state, java.io.DataInput dataInput)
          Override this if you need to read rules in from a binary stream
 void readRule(EvolutionState state, java.io.LineNumberReader reader)
          Reads a rule printed by printRule(...).
 void readRuleFromString(java.lang.String string, EvolutionState state)
          Reads a rule from a string, which may contain a final '\n'.
abstract  void reset(EvolutionState state, int thread)
          The reset method randomly reinitializes the rule.
 void setup(EvolutionState state, Parameter base)
          Sets up the object by reading it from the parameters stored in state, built off of the parameter base base.
 void writeRule(EvolutionState state, java.io.DataOutput dataOutput)
          Override this if you need to write rules out to a binary stream
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

P_RULE

public static final java.lang.String P_RULE
See Also:
Constant Field Values

P_CONSTRAINTS

public static final java.lang.String P_CONSTRAINTS
See Also:
Constant Field Values

constraints

public byte constraints
An index to a RuleConstraints

Constructor Detail

Rule

public Rule()
Method Detail

constraints

public final RuleConstraints constraints(RuleInitializer initializer)

hashCode

public abstract int hashCode()
Rulerates a hash code for this rule -- the rule for this is that the hash code must be the same for two rules that are equal to each other genetically.

Overrides:
hashCode in class java.lang.Object

equals

public abstract boolean equals(java.lang.Object other)
Unlike the standard form for Java, this function should return true if this rule is "genetically identical" to the other rule.

Overrides:
equals in class java.lang.Object

reset

public abstract void reset(EvolutionState state,
                           int thread)
The reset method randomly reinitializes the rule.


mutate

public void mutate(EvolutionState state,
                   int thread)
Mutate the rule. The default form just resets the rule.


printRuleForHumans

public void printRuleForHumans(EvolutionState state,
                               int log,
                               int verbosity)
Nice printing. The default form simply calls printRuleToStringForHumans and prints the result, but you might want to override this.


printRuleToStringForHumans

public java.lang.String printRuleToStringForHumans()
Nice printing to a string. The default form calls toString().


printRuleToString

public java.lang.String printRuleToString(EvolutionState state)
Deprecated. 

Prints the rule to a string in a fashion readable by readRuleFromString. The default form calls printRuleToString().


printRuleToString

public java.lang.String printRuleToString()
Prints the rule to a string in a fashion readable by readRuleFromString. The default form simply calls toString() -- you should just override toString() if you don't need the EvolutionState.


readRuleFromString

public void readRuleFromString(java.lang.String string,
                               EvolutionState state)
Reads a rule from a string, which may contain a final '\n'. Override this method. The default form generates an error.


printRule

public void printRule(EvolutionState state,
                      int log,
                      int verbosity)
Prints the rule in a way that can be read by readRule(). The default form simply calls printRuleToString(state). Override this rule to do custom writing to the log, or just override printRuleToString(...), which is probably easier to do.


printRule

public void printRule(EvolutionState state,
                      java.io.PrintWriter writer)
Prints the rule in a way that can be read by readRule(). The default form simply calls printRuleToString(state). Override this rule to do custom writing, or just override printRuleToString(...), which is probably easier to do.


readRule

public void readRule(EvolutionState state,
                     java.io.LineNumberReader reader)
              throws java.io.IOException
Reads a rule printed by printRule(...). The default form simply reads a line into a string, and then calls readRuleFromString() on that line. Override this rule to do custom reading, or just override readRuleFromString(...), which is probably easier to do.

Throws:
java.io.IOException

writeRule

public void writeRule(EvolutionState state,
                      java.io.DataOutput dataOutput)
               throws java.io.IOException
Override this if you need to write rules out to a binary stream

Throws:
java.io.IOException

readRule

public void readRule(EvolutionState state,
                     java.io.DataInput dataInput)
              throws java.io.IOException
Override this if you need to read rules in from a binary stream

Throws:
java.io.IOException

defaultBase

public Parameter defaultBase()
Description copied from interface: Prototype
Returns the default base for this prototype. This should generally be implemented by building off of the static base() method on the DefaultsForm object for the prototype's package. This should be callable during setup(...).

Specified by:
defaultBase in interface Prototype

clone

public java.lang.Object clone()
Description copied from interface: Prototype
Creates a new individual cloned from a prototype, and suitable to begin use in its own evolutionary context.

Typically this should be a full "deep" clone. However, you may share certain elements with other objects rather than clone hem, depending on the situation:

  • If you hold objects which are shared with other instances, don't clone them.
  • If you hold objects which must be unique, clone them.
  • If you hold objects which were given to you as a gesture of kindness, and aren't owned by you, you probably shouldn't clone them.
  • DON'T attempt to clone: Singletons, Cliques, or Groups.
  • Arrays are not cloned automatically; you may need to clone an array if you're not sharing it with other instances. Arrays have the nice feature of being copyable by calling clone() on them.

Implementations.

  • If no ancestor of yours implements clone(), and you have no need to do clone deeply, and you are abstract, then you should not declare clone().
  • If no ancestor of yours implements clone(), and you have no need to do clone deeply, and you are not abstract, then you should implement it as follows:

     public Object clone() 
         {
         try
             { 
             return super.clone();
             }
         catch ((CloneNotSupportedException e)
             { throw new InternalError(); } // never happens
         }
            
  • If no ancestor of yours implements clone(), but you need to deep-clone some things, then you should implement it as follows:

     public Object clone() 
         {
         try
             { 
             MyObject myobj = (MyObject) (super.clone());
    
             // put your deep-cloning code here...
             }
         catch ((CloneNotSupportedException e)
             { throw new InternalError(); } // never happens
         return myobj;
         } 
            
  • If an ancestor has implemented clone(), and you also need to deep clone some things, then you should implement it as follows:

     public Object clone() 
         { 
         MyObject myobj = (MyObject) (super.clone());
    
         // put your deep-cloning code here...
    
         return myobj;
         } 
            

Specified by:
clone in interface Prototype
Overrides:
clone in class java.lang.Object

setup

public void setup(EvolutionState state,
                  Parameter base)
Description copied from interface: Prototype
Sets up the object by reading it from the parameters stored in state, built off of the parameter base base. If an ancestor implements this method, be sure to call super.setup(state,base); before you do anything else.

For prototypes, setup(...) is typically called once for the prototype instance; cloned instances do not receive the setup(...) call. setup(...) may be called more than once; the only guarantee is that it will get called at least once on an instance or some "parent" object from which it was ultimately cloned.

Specified by:
setup in interface Prototype
Specified by:
setup in interface Setup

compareTo

public abstract int compareTo(java.lang.Object o)
This function replaces the old gt and lt functions that Rule used to require as it implemented the SortComparator interface. If you had implemented those old functions, you can simply implement this function as:
        public abstract int compareTo(Object o)
        {
        if (gt(this,o)) return 1;
        if (lt(this,o)) return -1;
        return 0;
        }
        

Specified by:
compareTo in interface java.lang.Comparable