net.sf.tweety.lp.asp.syntax

Class DLPAtom

java.lang.Object

net.sf.tweety.logics.commons.syntax.ComplexLogicalFormulaAdapter

net.sf.tweety.lp.asp.syntax.DLPElementAdapter

net.sf.tweety.lp.asp.syntax.DLPAtom

All Implemented Interfaces:

java.lang.Comparable<DLPLiteral>, Formula, Atom, ComplexLogicalFormula, Invertable, LogicStructure, SimpleLogicalFormula, DLPElement, DLPLiteral

public class DLPAtom
extends DLPElementAdapter
implements DLPLiteral

this class models an atom, which is a basic structure for building literals and rules for logic programs

Author:

Tim Janus, Thomas Vengels, Matthias Thimm

Nested Class Summary

Nested classes/interfaces inherited from interface net.sf.tweety.logics.commons.syntax.interfaces.Atom

Atom.AtomImpl, Atom.RETURN_SET_PREDICATE

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.List<Term<?>>	arguments a list of arguments of the atom
protected DLPPredicate	pred the predicate identifying the atom

Constructor Summary

Constructors

Constructor and Description
DLPAtom() Default-Ctor: Used for dynamic instantiation
DLPAtom(DLPAtom other) Copy-Ctor: Generates a deep copy of the given atom
DLPAtom(FOLAtom other) Copy-Ctor: Generates a deep copy of the given FOL atom
DLPAtom(java.lang.String symbol, java.util.List<? extends Term<?>> terms) Creates a predicate for the atom from symbol name and uses a list of terms as arguments for the atom.
DLPAtom(java.lang.String symbol, Term<?>... terms) Ctor: Creates an atom with the given predicate as name and the given terms as argument

Method Summary

Modifier and Type	Method and Description
void	addArgument(Term<?> arg) Adds an argument to the atom's argument list
DLPAtom	clone() Creates a deep copy of this formula
DLPAtom	cloneWithAddedTerm(Term<?> tval) Creates a copy of the literal and adds the given term as argument to the end of the argument list.
int	compareTo(DLPLiteral o)
DLPNeg	complement()
boolean	equals(java.lang.Object o)
java.util.List<? extends Term<?>>	getArguments()
int	getArity()
DLPAtom	getAtom()
java.util.Set<DLPAtom>	getAtoms() Processes the set of all atoms which appear in this formula
java.util.SortedSet<DLPLiteral>	getLiterals()
java.lang.String	getName()
DLPPredicate	getPredicate()
java.util.Set<DLPPredicate>	getPredicates() Processes the set of all predicates which appear in this formula
FolSignature	getSignature() Returns the signature of the language of this formula.
Term<?>	getTerm(int index)
java.util.Set<Term<?>>	getTerms()
int	hashCode()
boolean	isComplete()
boolean	isGround() Checks whether this formula is ground, i.e.
Atom.RETURN_SET_PREDICATE	setPredicate(Predicate predicate) Changes the predicate of the atom.
DLPAtom	substitute(Term<?> v, Term<?> t) Substitutes all occurrences of term "v" in this formula by term "t" and returns the new formula.
java.lang.String	toString()

Methods inherited from class net.sf.tweety.lp.asp.syntax.DLPElementAdapter

getPredicateCls

Methods inherited from class net.sf.tweety.logics.commons.syntax.ComplexLogicalFormulaAdapter

containsTermsOfType, exchange, getTerms, isLiteral, isWellFormed, substitute

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sf.tweety.logics.commons.syntax.interfaces.ComplexLogicalFormula

exchange, isWellFormed, substitute

Methods inherited from interface net.sf.tweety.logics.commons.syntax.interfaces.SimpleLogicalFormula

getPredicateCls, isLiteral

Methods inherited from interface net.sf.tweety.logics.commons.syntax.interfaces.LogicStructure

containsTermsOfType, getTerms

Field Detail

pred

protected DLPPredicate pred

the predicate identifying the atom

arguments

protected java.util.List<Term<?>> arguments

a list of arguments of the atom

Constructor Detail

DLPAtom

public DLPAtom()

Default-Ctor: Used for dynamic instantiation

DLPAtom

public DLPAtom(DLPAtom other)

Copy-Ctor: Generates a deep copy of the given atom

Parameters:

other - The atom acting as source for the deep copy

DLPAtom

public DLPAtom(FOLAtom other)

Copy-Ctor: Generates a deep copy of the given FOL atom

Parameters:

other - The FOL atom acting as source for the deep copy

DLPAtom

public DLPAtom(java.lang.String symbol,
               Term<?>... terms)

Ctor: Creates an atom with the given predicate as name and the given terms as argument

Parameters:

symbol - The name of the atom

terms - A list of Term defining the arguments of the term

DLPAtom

public DLPAtom(java.lang.String symbol,
               java.util.List<? extends Term<?>> terms)

Creates a predicate for the atom from symbol name and uses a list of terms as arguments for the atom. Size of terms determines arity of the predicate.

Method Detail

getAtom

public DLPAtom getAtom()

Specified by:

getAtom in interface DLPLiteral

Returns:

The atom representing the literal.

getArity

public int getArity()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getTerm

public Term<?> getTerm(int index)

cloneWithAddedTerm

public DLPAtom cloneWithAddedTerm(Term<?> tval)

Description copied from interface: DLPLiteral

Creates a copy of the literal and adds the given term as argument to the end of the argument list.

Specified by:

cloneWithAddedTerm in interface DLPLiteral

Parameters:

tval - the new argument.

Returns:

A copy of the literal containing the given term as new argument.

hashCode

public int hashCode()

Specified by:

hashCode in interface SimpleLogicalFormula

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object o)

Specified by:

equals in interface SimpleLogicalFormula

Overrides:

equals in class java.lang.Object

clone

public DLPAtom clone()

Description copied from interface: SimpleLogicalFormula

Creates a deep copy of this formula

Specified by:

clone in interface ComplexLogicalFormula

Specified by:

clone in interface SimpleLogicalFormula

Specified by:

clone in interface DLPElement

Specified by:

clone in class DLPElementAdapter

getName

public java.lang.String getName()

Specified by:

getName in interface Atom

Returns:

the name of the predicate

isGround

public boolean isGround()

Description copied from interface: ComplexLogicalFormula

Checks whether this formula is ground, i.e. whether there appears no variable in this formula.

Specified by:

isGround in interface ComplexLogicalFormula

Overrides:

isGround in class ComplexLogicalFormulaAdapter

Returns:

"true" if this formula is ground.

complement

public DLPNeg complement()

Specified by:

complement in interface Invertable

Specified by:

complement in interface DLPLiteral

Returns:

the complement of this formula.

substitute

public DLPAtom substitute(Term<?> v,
                          Term<?> t)
                   throws java.lang.IllegalArgumentException

Description copied from interface: ComplexLogicalFormula

Substitutes all occurrences of term "v" in this formula by term "t" and returns the new formula.

Specified by:

substitute in interface ComplexLogicalFormula

Specified by:

substitute in interface DLPElement

Specified by:

substitute in interface DLPLiteral

Parameters:

v - the term to be substituted.

t - the term to substitute.

Returns:

a formula where every occurrence of "v" is replaced by "t".

Throws:

java.lang.IllegalArgumentException - if "v" and "t" are of different sorts

getAtoms

public java.util.Set<DLPAtom> getAtoms()

Description copied from interface: SimpleLogicalFormula

Processes the set of all atoms which appear in this formula

Specified by:

getAtoms in interface SimpleLogicalFormula

Specified by:

getAtoms in interface DLPElement

Returns:

The set of all atoms

getPredicates

public java.util.Set<DLPPredicate> getPredicates()

Description copied from interface: SimpleLogicalFormula

Processes the set of all predicates which appear in this formula

Specified by:

getPredicates in interface SimpleLogicalFormula

Specified by:

getPredicates in interface DLPElement

Returns:

all predicates that appear in this formula

getSignature

public FolSignature getSignature()

Description copied from interface: Formula

Returns the signature of the language of this formula.

Specified by:

getSignature in interface Formula

Specified by:

getSignature in interface DLPElement

Returns:

the signature of the language of this formula.

getTerms

public java.util.Set<Term<?>> getTerms()

Specified by:

getTerms in interface LogicStructure

Returns:

a set containing all terms of this logical structure

getPredicate

public DLPPredicate getPredicate()

Specified by:

getPredicate in interface Atom

Returns:

the predicate of the atom

setPredicate

public Atom.RETURN_SET_PREDICATE setPredicate(Predicate predicate)

Description copied from interface: Atom

Changes the predicate of the atom. Given an old Predicate po and a new predicate pn with their list of arguments types at(po) and at(pn) and the arguments of this Atom: arg(this) this method distinguishes between three cases: 1. The predicate only differ in the names, returning RSP_SUCCESS 2. The old predicates argument types is a sub-list of the new argument types then the method returns RSP_INCOMPLETE and the atoms isComplete() method returns false 3. The new predicates argument types is a sub-list of the old argument types then the method returns RSP_TRUNCATED and the arguments of this atom are truncated too and isComplete() returns true. 4. The old and new predicates' argument types differ then the list of arguments of the atom get cleared and isComplete() returns false.

Specified by:

setPredicate in interface Atom

Returns:

Depends on the cases described above: 1. RSP_SUCCESS 2. RSP_INCOMPLETE 3. RSP_TRUNCATED 4. RSP_CLEARED

addArgument

public void addArgument(Term<?> arg)
                 throws LanguageException

Description copied from interface: Atom

Adds an argument to the atom's argument list

Specified by:

addArgument in interface Atom

Parameters:

arg - The next argument

Throws:

LanguageException - If the language does not support arguments for their constructs.

getArguments

public java.util.List<? extends Term<?>> getArguments()

Specified by:

getArguments in interface Atom

Returns:

A list containing all the arguments of this specific atom

isComplete

public boolean isComplete()

Specified by:

isComplete in interface Atom

Returns:

true if the size of the argument list is equal to the arity of the predicate

getLiterals

public java.util.SortedSet<DLPLiteral> getLiterals()

Specified by:

getLiterals in interface DLPElement

Returns:

all the literals used in the rule element

compareTo

public int compareTo(DLPLiteral o)

Specified by:

compareTo in interface java.lang.Comparable<DLPLiteral>