ai.planning.propositional
Class Domain

java.lang.Object
  ai.planning.propositional.Domain

All Implemented Interfaces:

Domain<ai.krr.propositions.Atom>, inf.compilers.SyntaxAdaptable

public class Domain
extends java.lang.Object
implements Domain<ai.krr.propositions.Atom>, inf.compilers.SyntaxAdaptable

A propositional planning domain corresponds to a state-transition system in which the state space is implicitly defined by the propositional Atoms used to define the Domain and the planning problems for this Domain. The state-transition function is also defined implicitly by the actions defined in the Domain. Thus, the most important explicit component defining Domain here is the set of ActionTypes the provide the possible actions. The only additional element defined here is the name of the Domain.

Author:

Gerhard Wickler

Field Summary

protected static java.util.Map<ai.krr.NamedSymbol,Domain>	allDomains all known Domains indexed by their name
protected static inf.compilers.SyntaxAdaptor<Domain>	ioAdaptor the SyntaxAdaptor used for input/output operations
protected ai.krr.NamedSymbol	name the name given to this Domain
protected java.util.List<ActionType>	operators the ActionTypes that define this Domain

Constructor Summary

Domain(ai.krr.NamedSymbol name, ActionType... ops)
This constructor creates a new Domain that has the given name and is defined by the given ActionTypes.

Domain(ai.krr.NamedSymbol name, java.util.Collection<ActionType> ops)
This constructor creates a new Domain that has the given name and is defined by the given ActionTypes.

Method Summary

protected Domain	clone() This class does not support cloning and an Exception will be thrown if this method is called.
ai.krr.NamedSymbol	getName() This function returns the name of this Domain.
ActionType	getOperator(ai.krr.NamedSymbol name) This function returns the ActionType with the given name that may be defined in this Domain.
java.util.List<ActionType>	getOperators() This function returns the List of ActionTypes that define this Domain.
java.util.Set<Goal>	getSubGoals(Goal goal) This function computes the regression set of the given Goal.
java.util.Set<Goal>	getSubGoals(java.util.Set<Goal> goals) This function computes the possible sub-goals of the given Set of Goals.
java.util.Set<WorldState>	getSuccessors(java.util.Set<WorldState> states) This function computes all the successor states of the given Set of WorldStates.
java.util.Set<WorldState>	getSuccessors(WorldState state) This function computes all the successor states of the given WorldState.
int	hashCode() This function returns a hash value for this domain.
void	prettyPrint(int indent, java.io.Writer w, inf.compilers.SyntaxAdaptor sa) This function can be used write this SyntaxAdaptable object to the given Writer.
static Domain	read(java.io.Reader r, inf.compilers.SyntaxAdaptor<Domain> sa) This function can be used to parse a Domain from the given Reader.
static Domain	readFromFile(java.io.File file) This convenience function can be used to read a Domain from the given File.
static void	setSyntax(inf.compilers.SyntaxAdaptor<Domain> sa) This function can be used to define the syntax with which instances of this class are written or read.
java.lang.String	toString() This function returns a String representation of this Domain.
void	write(java.io.Writer w, inf.compilers.SyntaxAdaptor sa) This function can be used write this propositional Domain to the given Writer.
void	writeToFile(java.io.File file) This convenience function can be used to write this Domain to the given File.

Methods inherited from class java.lang.Object

equals, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

allDomains

protected static java.util.Map<ai.krr.NamedSymbol,Domain> allDomains

all known Domains indexed by their name

ioAdaptor

protected static inf.compilers.SyntaxAdaptor<Domain> ioAdaptor

the SyntaxAdaptor used for input/output operations

name

protected final ai.krr.NamedSymbol name

the name given to this Domain

operators

protected java.util.List<ActionType> operators

the ActionTypes that define this Domain

Constructor Detail

Domain

public Domain(ai.krr.NamedSymbol name,
              java.util.Collection<ActionType> ops)

This constructor creates a new Domain that has the given name and is defined by the given ActionTypes. Note that ActionTypes should have unique names, which is verified if assertions are on.

Parameters:

name - the Symbol representing the name of this Domain

ops - the ActionTypes in this Domain

Domain

public Domain(ai.krr.NamedSymbol name,
              ActionType... ops)

This constructor creates a new Domain that has the given name and is defined by the given ActionTypes. This constructor simply uses the one taking a Collection of ActionTypes

Parameters:

name - the Symbol representing the name of this Domain

ops - the ActionTypes in this Domain

Method Detail

clone

protected Domain clone()
                throws java.lang.CloneNotSupportedException

This class does not support cloning and an Exception will be thrown if this method is called.

Overrides:

clone in class java.lang.Object

Returns:

nothing

Throws:

java.lang.CloneNotSupportedException - will be thrown

getName

public final ai.krr.NamedSymbol getName()

This function returns the name of this Domain.

Specified by:

getName in interface Domain<ai.krr.propositions.Atom>

Returns:

the symbolic name of this Domain

getOperators

public java.util.List<ActionType> getOperators()

This function returns the List of ActionTypes that define this Domain.

Specified by:

getOperators in interface Domain<ai.krr.propositions.Atom>

Returns:

the ActionTypes in this Domain

getOperator

public ActionType getOperator(ai.krr.NamedSymbol name)

This function returns the ActionType with the given name that may be defined in this Domain. It returns null if there is no ActionType with the given name.

Specified by:

getOperator in interface Domain<ai.krr.propositions.Atom>

Parameters:

name - the name identifying the ActionType

Returns:

the ActionType with the given (unique) name

write

public void write(java.io.Writer w,
                  inf.compilers.SyntaxAdaptor sa)
           throws inf.compilers.ExpressivenessException,
                  java.io.IOException

This function can be used write this propositional Domain to the given Writer. The syntax in which it is written is defined by the SyntaxAdaptor that is also given to this function.

Specified by:

write in interface inf.compilers.SyntaxAdaptable

Parameters:

w - the Writer to which this Domain is written

sa - the SyntaxAdaptor that determines the syntax

Throws:

inf.compilers.ExpressivenessException - if the syntax does not support every construct occurring in this Domain

java.io.IOException - if writing to the Writer fails

prettyPrint

public void prettyPrint(int indent,
                        java.io.Writer w,
                        inf.compilers.SyntaxAdaptor sa)
                 throws inf.compilers.ExpressivenessException,
                        java.io.IOException

This function can be used write this SyntaxAdaptable object to the given Writer. The syntax is the same as for normal writing. The only difference is the inclusion of extra space and newlines for better readability.

Specified by:

prettyPrint in interface inf.compilers.SyntaxAdaptable

Parameters:

indent - the amount of indentation for the first line

w - the Writer to which this Sentence is written

sa - the SyntaxAdaptor that determines the syntax

Throws:

inf.compilers.ExpressivenessException - if the syntax does not support every construct occurring in this Sentence

java.io.IOException - if writing to the Writer fails

getSuccessors

public java.util.Set<WorldState> getSuccessors(WorldState state)

This function computes all the successor states of the given WorldState. This domain defines the ActionTypes that may be used to generate the successors.

Parameters:

state - the WorldState from which the successors are generated

Returns:

the Set of all the states reachable from this one

getSuccessors

public java.util.Set<WorldState> getSuccessors(java.util.Set<WorldState> states)

This function computes all the successor states of the given Set of WorldStates. This domain defines the ActionTypes that may be used to generate the successors.

Parameters:

states - the WorldStates from which the successors are generated

Returns:

the Set of all the states reachable from the given states

getSubGoals

public java.util.Set<Goal> getSubGoals(Goal goal)

This function computes the regression set of the given Goal. If a WorldState satisfies any one of these sub-goals then a state in which this Goal is satisfied is reachable. This domain defines the ActionTypes that may be used to generate the sub-goals.

Parameters:

goal - the Goal of which the possible sub-goals are to be computed

Returns:

the Set of all the sub-goals that may lead to this Goal being achieved

getSubGoals

public java.util.Set<Goal> getSubGoals(java.util.Set<Goal> goals)

This function computes the possible sub-goals of the given Set of Goals. If a WorldState satisfies any one of these sub-goals then a state in which a Goal in the given Set is satisfied is reachable. This domain defines the ActionTypes that may be used to generate the sub-goals.

Parameters:

goals - the Goals of which the possible sub-goals are to be computed

Returns:

the Set of all the sub-goals that may lead to the given Goals being achieved

writeToFile

public void writeToFile(java.io.File file)
                 throws java.io.IOException,
                        inf.compilers.ExpressivenessException

This convenience function can be used to write this Domain to the given File. Note that it actually pretty-prints this domain. The SyntaxAdaptor used can specified using setSyntax(SyntaxAdaptor).

Parameters:

file - the File to which this Domain is to be written

Throws:

java.io.IOException - if writing to the File fails

inf.compilers.ExpressivenessException - if the SyntaxAdaptor used throws this Exception

toString

public java.lang.String toString()

This function returns a String representation of this Domain. The exact syntax is determined by the SyntaxAdaptor used, which can be set using setSyntax(SyntaxAdaptor). If the transformation causes an ExpressivenessException (if there are constructs in this Domain that cannot be expressed in the syntax) this function will return null.

Overrides:

toString in class java.lang.Object

Returns:

a String representation of this Domain

hashCode

public int hashCode()

This function returns a hash value for this domain.

Overrides:

hashCode in class java.lang.Object

Returns:

an integer that can be used for hashing

setSyntax

public static void setSyntax(inf.compilers.SyntaxAdaptor<Domain> sa)

This function can be used to define the syntax with which instances of this class are written or read. The default is the PPL syntax defined by a PplDomainAdaptor.

Parameters:

sa - the SyntaxAdaptor that defines the syntax for I/O operations

read

public static Domain read(java.io.Reader r,
                          inf.compilers.SyntaxAdaptor<Domain> sa)
                   throws inf.compilers.ExpressivenessException,
                          java.text.ParseException,
                          java.io.IOException

This function can be used to parse a Domain from the given Reader. The syntax that is expected from the input and how this is transformed into a propositional Domain is determined by the given SyntaxAdaptor.

Parameters:

r - the Reader from which character input is parsed

sa - the SyntaxAdaptor that creates the Domain

Returns:

a new Domain corresponding to the given input

Throws:

inf.compilers.ExpressivenessException - if the syntax does not support every construct occurring in the input

java.text.ParseException - if the input contains syntax errors

java.io.IOException - if reading from the Reader fails

readFromFile

public static Domain readFromFile(java.io.File file)
                           throws inf.compilers.ExpressivenessException,
                                  java.text.ParseException,
                                  java.io.IOException

This convenience function can be used to read a Domain from the given File. It uses the SyntaxAdaptor that can be set using setSyntax(SyntaxAdaptor) to perform this operation.

Parameters:

file - the File from which the Domain is to be read

Returns:

the Domain defined in the given file

Throws:

inf.compilers.ExpressivenessException - if the syntax does not support every construct occurring in the input

java.text.ParseException - if the input contains syntax errors

java.io.IOException - if reading from the File fails