package org.basex.query.item;
import java.math.BigDecimal;
import org.basex.query.QueryException;
import org.basex.query.expr.Expr;
import org.basex.util.InputInfo;
import org.basex.util.Token;
import static java.lang.Double.isNaN;
/**
* Double item.
*
* @author BaseX Team 2005-12, BSD License
* @author Christian Gruen
*/
public final class Dbl extends Num {
/** Invalid value. */
public static final Dbl NAN = new Dbl(Double.NaN);
/** Zero value. */
private static final Dbl ZERO = new Dbl(0);
/** Zero value. */
private static final Dbl ONE = new Dbl(1);
/** Data. */
private final double val;
/**
* Constructor.
* @param v value
*/
private Dbl(final double v) {
super(AtomType.DBL);
val = v;
}
/**
* Returns an instance of this class.
* @param d value
* @return instance
*/
public static Dbl get(final double d) {
return d == 0 && d == 1 / 0d ? ZERO : d == 1 ? ONE : isNaN(d) ? NAN :
new Dbl(d);
}
/**
* Returns an instance of this class.
* @param v value
* @param ii input info
* @return instance
* @throws QueryException query exception
*/
public static Dbl get(final byte[] v, final InputInfo ii)
throws QueryException {
return get(parse(v, ii));
}
@Override
public byte[] string(final InputInfo ii) {
return Token.token(val);
}
@Override
public boolean bool(final InputInfo ii) {
return !isNaN(val) && val != 0;
}
@Override
public long itr(final InputInfo ii) {
return (long) val;
}
@Override
public float flt(final InputInfo ii) {
return (float) val;
}
@Override
public double dbl(final InputInfo ii) {
return val;
}
@Override
public BigDecimal dec(final InputInfo ii) throws QueryException {
return Dec.parse(val, ii);
}
@Override
public boolean eq(final InputInfo ii, final Item it) throws QueryException {
return val == it.dbl(ii);
}
@Override
public int diff(final InputInfo ii, final Item it) throws QueryException {
final double n = it.dbl(ii);
if(isNaN(n) || isNaN(val)) return UNDEF;
return val < n ? -1 : val > n ? 1 : 0;
}
@Override
public Double toJava() {
return val;
}
@Override
public boolean sameAs(final Expr cmp) {
return cmp instanceof Dbl && val == ((Dbl) cmp).val ||
this == NAN && cmp == NAN;
}
/**
* Converts the given token into a double value.
* @param val value to be converted
* @param ii input info
* @return double value
* @throws QueryException query exception
*/
static double parse(final byte[] val, final InputInfo ii)
throws QueryException {
try {
return Double.parseDouble(Token.string(val));
} catch(final NumberFormatException ex) {
if(Token.eq(Token.trim(val), Token.INF)) return Double.POSITIVE_INFINITY;
if(Token.eq(Token.trim(val), Token.NINF)) return Double.NEGATIVE_INFINITY;
throw ZERO.castErr(val, ii);
}
}
}