Package jsetl

Class Ris

java.lang.Object

jsetl.LObject

jsetl.LCollection

jsetl.LSet

jsetl.Ris

All Implemented Interfaces:

java.lang.Cloneable, java.lang.Iterable<java.lang.Object>

public class Ris
extends LSet

Objects of this class are restricted intentional sets of the form {x : D | F(x) @ P(x)}, which denote the intensional set {P(x) | x in D and F(x)}. x is the control term of the RIS, i.e. a dummy variable, D is the domain of the RIS, i.e. a finite (possibly unspecified) s that is also the domain of x. F(x), the filter, is a constraint in which could appear x or free variables (or dummy variables) defined outside of the RIS, this constraint must be satisfied by all x in order for them to be used in the formula P(x), the pattern, to form the member terms of the intensional set.

Field Summary

Fields inherited from class jsetl.LObject

USEJOLLYTOKEN

Constructor Summary

Constructors

Constructor	Description
Ris(LObject controlTerm, LSet domain, Constraint filter)	Constructs the restricted intensional set {controlTerm : domain | filter @ controlTerm}.
Ris(LObject controlTerm, LSet domain, Constraint filter, LObject pattern, LObject... dummyVariables)	Constructs the restricted intensional set {controlTerm : domain | filter @ pattern} and treats each variable in dummyVariables as a dummy variable (i.e. creates a new instance for every application of filter and pattern).
Ris(Ris ris)	Constructs a restricted intensional set that has the same controlTerm, domain, filter, pattern and dummy variables as the argument ris.

Method Summary

Modifier and Type	Method	Description
java.lang.Object	accept(jsetl.Visitor visitor)	Needed for the Visitor pattern to work.
Ris	clone()	Constructs and returns a clone of this Ris, the same as new Ris(this).
boolean	equals(java.lang.Object object)	Checks whether this object is equal to the parameter object.
LSet	expand()	Returns a logical set containing the expansion of this Ris, if it is expandable.
Constraint	forallElems(LVar lVar, Constraint constraint)	This method returns a constraint that is true if and only if for every element in this, that element satisfies the constraint constraint with lVar replaced with such element in it.
LObject	getControlTerm()	Return the control term of this Ris.
LSet	getDomain()	Return the domain of this Ris.
Constraint	getFilter()	Return the filter of this Ris.
LObject	getPattern()	Return the pattern of this Ris.
int	getSize()	Calling this method is the same as calling this.expand().getSize().
Ris	getTail()	Returns tha tail of this restricted intensional set, which is this.
java.util.HashSet<?>	getValue()	Same as calling getValue() on the value returned by the expand() method.
int	hashCode()	Returns the hashcode for this Ris.
boolean	isBound()	Checks whether the Ris domain is bound or not.
boolean	isClosed()	Checks whether the Ris domain is closed or not.
boolean	isExpandable()	Checks whether this Ris is expandable or not.
boolean	isGround()	Checks whether the Ris is ground or not: it is if and only if its domain is ground.
java.util.Iterator<java.lang.Object>	iterator()	Calling this method is the same as calling this.expand().iterator().
Ris	normalizeSet()	This operation is not supported by Ris, so it will always throw UnsupportedOperationException.
boolean	occurs(java.lang.Object object)	Tests whether this Ris contains the parameter object as its (or inside its) control term, domain, filter or pattern.
void	output()	Outputs a description of this Ris to the standard output.
void	printElems(char delimiter)	Calling this method is the same as calling this.expand().getSize(delimiter).
Ris	setName(java.lang.String name)	Sets the name of this Ris to name and returns this.
LSet	setValue(java.util.Set<?> value)	Calling this method always throws UnsupportedOperationException.
java.lang.Object[]	toArray()	Calling this method is the same as calling this.expand().toArray().
java.lang.String	toString()	Constructs and returns a string representation of this restricted intensional set, the string is of the form "{ controlTerm : domain | filter @ pattern }".

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from class jsetl.LCollection

isEmpty, testContains

Methods inherited from class jsetl.LObject

getName, in, in, isGround, nin, nin

Methods inherited from class jsetl.LSet

contains, diff, diff, diff, diff, disj, disj, empty, eq, eq, ins, insAll, insAll, inters, inters, inters, inters, less, less, less, less, mkSet, ncontains, ndiff, ndiff, ndiff, ndiff, ndisj, ndisj, neq, neq, ninters, ninters, ninters, ninters, nsubset, nsubset, nunion, nunion, nunion, nunion, size, size, subset, subset, union, union, union, union

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Ris

public Ris(@NotNull
           LObject controlTerm,
           @NotNull
           LSet domain,
           @NotNull
           Constraint filter,
           @NotNull
           LObject pattern,
           @NotNull
           LObject... dummyVariables)

Constructs the restricted intensional set {controlTerm : domain | filter @ pattern} and treats each variable in dummyVariables as a dummy variable (i.e. creates a new instance for every application of filter and pattern). Note that also the variables created to represent the flattened form of expressions are treated as dummy variables, even if they do not occur in dummyVariables.

Parameters:

controlTerm - control term of this Ris.

domain - domain of this of this Ris.

filter - filter of this Ris.

pattern - pattern of this Ris.

dummyVariables - each variable in this array will be treated as a dummy variable if it occurs in filter or pattern. It can not contain null values.

Throws:

java.lang.NullPointerException - if dummyVariables contains null values.

Ris

public Ris(@NotNull
           LObject controlTerm,
           @NotNull
           LSet domain,
           @NotNull
           Constraint filter)

Constructs the restricted intensional set {controlTerm : domain | filter @ controlTerm}. Note that also the variables created to represent the flattened form of expressions are treated as dummy dummyVariables.

Parameters:

controlTerm - control term (and pattern) of this Ris.

domain - domain of this of this Ris.

filter - filter of this Ris.

Ris

public Ris(@NotNull
           Ris ris)

Constructs a restricted intensional set that has the same controlTerm, domain, filter, pattern and dummy variables as the argument ris.

Parameters:

ris - the restricted intensional set to copy.

Method Detail

getControlTerm

@NotNull
public LObject getControlTerm()

Return the control term of this Ris.

Returns:

the control term.

getDomain

@NotNull
public LSet getDomain()

Return the domain of this Ris.

Returns:

the domain.

getFilter

@NotNull
public Constraint getFilter()

Return the filter of this Ris.

Returns:

the filter.

getPattern

@NotNull
public LObject getPattern()

Return the pattern of this Ris.

Returns:

the pattern.

setName

@NotNull
public Ris setName(@NotNull
                   java.lang.String name)

Sets the name of this Ris to name and returns this.

Overrides:

setName in class LSet

Parameters:

name - the new name for this Ris.

Returns:

the invocation object.

getValue

public java.util.HashSet<?> getValue()

Same as calling getValue() on the value returned by the expand() method.

Overrides:

getValue in class LSet

Returns:

the value of this Ris.

Throws:

java.lang.IllegalStateException - if this Ris is not expandable.

See Also:

expand(), isExpandable()

output

public void output()

Outputs a description of this Ris to the standard output. The description is of the form "name = toString".

Overrides:

output in class LObject

clone

@NotNull
public Ris clone()

Constructs and returns a clone of this Ris, the same as new Ris(this).

Overrides:

clone in class LSet

Returns:

a clone of this ris.

isExpandable

public boolean isExpandable()

Checks whether this Ris is expandable or not. A Ris is expandable if and only if its domain is empty or (it has at least a ground element and the filter has no free (not dummy and not part of control term) variables).

Returns:

true if this Ris is expandable, false otherwise.

See Also:

expand()

expand

@NotNull
public LSet expand()

Returns a logical set containing the expansion of this Ris, if it is expandable. The expansion of a Ris is a LSet containing each possible P(d) for each ground d in domain that satisfies F(d). The constructed LSet has an empty tail (LSet.empty()) if the domain of the Ris is ground, otherwise it is a Ris with the same control term, filter and pattern as the original Ris and a LSet containing each non-ground element of domain as its domain.

Returns:

the expansion of this Ris.

Throws:

java.lang.IllegalStateException - if the this Ris is not expandable

See Also:

isExpandable()

getTail

@NotNull
public Ris getTail()

Returns tha tail of this restricted intensional set, which is this.

Overrides:

getTail in class LSet

Returns:

this.

isBound

public boolean isBound()

Checks whether the Ris domain is bound or not.

Overrides:

isBound in class LObject

Returns:

true if the domain of this Ris is initialized, false otherwise.

See Also:

LObject.isInitialized()

isGround

public boolean isGround()

Checks whether the Ris is ground or not: it is if and only if its domain is ground.

Overrides:

isGround in class LCollection

Returns:

true if this Ris is ground, false otherwise.

isClosed

public boolean isClosed()

Checks whether the Ris domain is closed or not.

Overrides:

isClosed in class LCollection

Returns:

true if this Ris domain is closed, false otherwise.

toString

@NotNull
public java.lang.String toString()

Constructs and returns a string representation of this restricted intensional set, the string is of the form "{ controlTerm : domain | filter @ pattern }".

Overrides:

toString in class LSet

Returns:

a string representation of this Ris.

occurs

public boolean occurs(@NotNull
                      java.lang.Object object)

Tests whether this Ris contains the parameter object as its (or inside its) control term, domain, filter or pattern.

Overrides:

occurs in class LSet

Parameters:

object - object to search inside this.

Returns:

true if object appears inside this, false otherwise.

equals

public boolean equals(@Nullable
                      java.lang.Object object)

Checks whether this object is equal to the parameter object. Note that equal Riss will have the same hash code.

Overrides:

equals in class LSet

Parameters:

object - the supposedly equal object.

Returns:

true if this object is equal to object, false otherwise.

hashCode

public int hashCode()

Returns the hashcode for this Ris. Note that equal Riss will have the same hash code.

Overrides:

hashCode in class java.lang.Object

Returns:

the hashcode.

iterator

@NotNull
public java.util.Iterator<java.lang.Object> iterator()

Calling this method is the same as calling this.expand().iterator().

Specified by:

iterator in interface java.lang.Iterable<java.lang.Object>

Overrides:

iterator in class LCollection

Returns:

an iterator over the expansion of this Ris.

Throws:

java.lang.IllegalStateException - if this Ris is not expandable.

See Also:

expand(), isExpandable()

getSize

public int getSize()

Calling this method is the same as calling this.expand().getSize().

Overrides:

getSize in class LSet

Returns:

the size of the expansion of this Ris.

Throws:

java.lang.IllegalStateException - if this Ris is not expandable.

See Also:

expand(), isExpandable()

toArray

@NotNull
public java.lang.Object[] toArray()

Calling this method is the same as calling this.expand().toArray().

Overrides:

toArray in class LCollection

Returns:

an array of objects containing all the elements of the expansion of this ris.

Throws:

java.lang.IllegalStateException - if this Ris is not expandable.

See Also:

expand(), isExpandable()

printElems

public void printElems(char delimiter)

Calling this method is the same as calling this.expand().getSize(delimiter). It outputs to standard output the list of elements in the expansion of this Ris separated by delimiter.

Overrides:

printElems in class LSet

Parameters:

delimiter - character to use between elements.

Throws:

java.lang.IllegalStateException - if this Ris is not expandable.

See Also:

expand(), isExpandable()

accept

@Nullable
public java.lang.Object accept(@NotNull
                               jsetl.Visitor visitor)

Needed for the Visitor pattern to work.

Overrides:

accept in class LSet

Parameters:

visitor - the visitor that wants to visit the object.

Returns:

the result of visitor.visit(this)

forallElems

@NotNull
public Constraint forallElems(@NotNull
                              LVar lVar,
                              @NotNull
                              Constraint constraint)

This method returns a constraint that is true if and only if for every element in this, that element satisfies the constraint constraint with lVar replaced with such element in it.

Overrides:

forallElems in class LCollection

Parameters:

lVar - the dummy logical variable used in the constraint constraint.

constraint - a constraint conjunction which should be satisfied for each (known) element of this collection, after substituting y with them.

Returns:

the constructed conjunction of constraints

normalizeSet

@UnsupportedOperation
public Ris normalizeSet()

This operation is not supported by Ris, so it will always throw UnsupportedOperationException.

Overrides:

normalizeSet in class LSet

Returns:

nothing, throws an exception always.

Throws:

java.lang.UnsupportedOperationException - always.

setValue

@UnsupportedOperation
public LSet setValue(java.util.Set<?> value)

Calling this method always throws UnsupportedOperationException.

Overrides:

setValue in class LSet

Parameters:

value - the value to s.

Returns:

nothing, it always throws an exception.

Throws:

java.lang.UnsupportedOperationException - always.