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package jmathexpr.arithmetic.rational;
import jmathexpr.Expression;
import jmathexpr.bool.TruthValue;
import jmathexpr.arithmetic.ANumber;
import jmathexpr.arithmetic.Numbers;
import jmathexpr.arithmetic.integer.Integers;
import jmathexpr.arithmetic.natural.Naturals;
import jmathexpr.arithmetic.rational.impl.LongRationalFactory;
import jmathexpr.arithmetic.real.Reals;
import jmathexpr.set.Cardinality;
import jmathexpr.set.Set;
/**
* The set of all rational numbers.
*
* @author Elemér Furka
*/
public class Rationals extends Numbers implements RationalFactory {
private static final Rationals INSTANCE = new Rationals();
private final RationalFactory factory;
private Rationals() {
this(new LongRationalFactory());
}
private Rationals(RationalFactory factory) {
super('Q', "\u2124");
this.factory = factory;
}
public static Rationals getInstance() {
return INSTANCE;
}
public static Rationals getInstance(RationalFactory factory) {
return new Rationals(factory);
}
@Override
public Rationals evaluate() {
return this;
}
@Override
public TruthValue contains(Expression element) {
return element instanceof ANumber ? TruthValue.valueOf(((ANumber) element).isRational()) : TruthValue.False;
}
@Override
public boolean subsetOf(Set set) {
if (equals(set)) {
return true;
} else if (set.equals(Reals.getInstance())) {
return true;
} else if (set.equals(Naturals.getInstance()) || set.equals(Integers.getInstance())) {
return false;
}
throw new IllegalStateException("Missing implementation: " + set);
}
@Override
public RationalNumber create(String asString) {
return factory.create(asString);
}
@Override
public RationalNumber create(String numerator, String denominator) {
return factory.create(numerator, denominator);
}
@Override
public RationalNumber create(long numerator, long denominator) {
return factory.create(numerator, denominator);
}
@Override
public Set domain() {
return this;
}
@Override
public Set codomain() {
return this;
}
@Override
public Cardinality cardinality() {
return Cardinality.aleph(0);
}
}