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An OSGi bundle for Saxon-HE
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2013 Saxonica Limited.
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.value;
import net.sf.saxon.expr.sort.DoubleSortComparer;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.tree.util.FastStringBuffer;
import net.sf.saxon.type.AtomicType;
import net.sf.saxon.type.BuiltInAtomicType;
import java.math.BigDecimal;
import java.math.BigInteger;
/**
* A numeric (double precision floating point) value
*/
public final class DoubleValue extends NumericValue {
public static final DoubleValue ZERO = new DoubleValue(0.0);
public static final DoubleValue NEGATIVE_ZERO = new DoubleValue(-0.0);
public static final DoubleValue ONE = new DoubleValue(1.0);
public static final DoubleValue NaN = new DoubleValue(Double.NaN);
private double value;
/**
* Constructor supplying a double
* @param value the value of the NumericValue
*/
public DoubleValue(double value) {
this.value = value;
typeLabel = BuiltInAtomicType.DOUBLE;
}
/**
* Constructor supplying a double and an AtomicType, for creating
* a value that belongs to a user-defined subtype of xs:double. It is
* the caller's responsibility to ensure that the supplied value conforms
* to the supplied type.
* @param value the value of the NumericValue
* @param type the type of the value. This must be a subtype of xs:double, and the
* value must conform to this type. The methosd does not check these conditions.
*/
public DoubleValue(double value, AtomicType type) {
this.value = value;
typeLabel = type;
}
/**
* Static factory method (for convenience in compiled bytecode)
* @param value the value of the double
* @return a new DoubleValue
*/
public static DoubleValue makeDoubleValue(double value) {
return new DoubleValue(value);
}
/**
* Create a copy of this atomic value, with a different type label
*
* @param typeLabel the type label of the new copy. The caller is responsible for checking that
* the value actually conforms to this type.
*/
/*@NotNull*/ public AtomicValue copyAsSubType(AtomicType typeLabel) {
DoubleValue v = new DoubleValue(value);
v.typeLabel = typeLabel;
return v;
}
/**
* Determine the primitive type of the value. This delivers the same answer as
* getItemType().getPrimitiveItemType(). The primitive types are
* the 19 primitive types of XML Schema, plus xs:integer, xs:dayTimeDuration and xs:yearMonthDuration,
* and xs:untypedAtomic. For external objects, the result is AnyAtomicType.
*/
public BuiltInAtomicType getPrimitiveType() {
return BuiltInAtomicType.DOUBLE;
}
/**
* Return this numeric value as a double
* @return the value as a double
*/
public double getDoubleValue() {
return value;
}
/**
* Get the numeric value converted to a float
*
* @return a float representing this numeric value; NaN if it cannot be converted
*/
@Override
public float getFloatValue() {
return (float)value;
}
/**
* Get the numeric value converted to a decimal
*
* @return a decimal representing this numeric value;
* @throws net.sf.saxon.trans.XPathException
* if the value cannot be converted, for example if it is NaN or infinite
*/
@Override
public BigDecimal getDecimalValue() throws XPathException {
return new BigDecimal(value);
}
/**
* Return the numeric value as a Java long.
*
* @return the numeric value as a Java long. This performs truncation
* towards zero.
* @throws net.sf.saxon.trans.XPathException
* if the value cannot be converted
*/
@Override
public long longValue() throws XPathException {
return (long)value;
}
/**
* Get the hashCode. This must conform to the rules for other NumericValue hashcodes
* @see NumericValue#hashCode
*/
public int hashCode() {
if (value > Integer.MIN_VALUE && value < Integer.MAX_VALUE) {
return (int)value;
} else {
return new Double(value).hashCode();
}
}
/**
* Test whether the value is the double/float value NaN
*/
public boolean isNaN() {
return Double.isNaN(value);
}
/**
* Get the effective boolean value
* @return the effective boolean value (true unless the value is zero or NaN)
*/
public boolean effectiveBooleanValue() {
return (value!=0.0 && !Double.isNaN(value));
}
/**
* Convert the double to a string according to the XPath 2.0 rules
* @return the string value
*/
// public String getStringValue() {
// return doubleToString(value).toString(); //, Double.toString(value)).toString();
// }
/**
* Convert the double to a string according to the XPath 2.0 rules
* @return the string value
*/
public CharSequence getPrimitiveStringValue() {
return doubleToString(value);
}
/**
* Get the canonical lexical representation as defined in XML Schema. This is not always the same
* as the result of casting to a string according to the XPath rules. For xs:double, the canonical
* representation always uses exponential notation.
*/
public CharSequence getCanonicalLexicalRepresentation() {
FastStringBuffer fsb = new FastStringBuffer(FastStringBuffer.TINY);
return FloatingPointConverter.appendDouble(fsb, value, true);
}
/**
* Internal method used for conversion of a double to a string
* @param value the actual value
* @return the value converted to a string, according to the XPath casting rules.
*/
public static CharSequence doubleToString(double value) {
return FloatingPointConverter.appendDouble(new FastStringBuffer(FastStringBuffer.TINY), value, false);
}
/**
* Negate the value
*/
public NumericValue negate() {
return new DoubleValue(-value);
}
/**
* Implement the XPath floor() function
*/
public NumericValue floor() {
return new DoubleValue(Math.floor(value));
}
/**
* Implement the XPath ceiling() function
*/
public NumericValue ceiling() {
return new DoubleValue(Math.ceil(value));
}
/**
* Implement the XPath round() function
*/
public NumericValue round(int scale) {
if (Double.isNaN(value)) {
return this;
}
if (Double.isInfinite(value)) {
return this;
}
if (value == 0.0) {
return this; // handles the negative zero case
}
if (value == -0.0) {
return this; // handles the negative zero case
}
if (value >= -0.5 && value < 0.0) {
return new DoubleValue(-0.0);
}
if (scale==0 && value > Long.MIN_VALUE && value < Long.MAX_VALUE) {
return new DoubleValue(Math.round(value));
}
// Convert to a scaled integer, by multiplying by 10^scale
double factor = Math.pow(10, scale+1);
double d = Math.abs(value * factor);
if (Double.isInfinite(d)) {
// double arithmetic has overflowed - do it in decimal
BigDecimal dec = new BigDecimal(value);
dec = dec.setScale(scale, BigDecimal.ROUND_HALF_UP);
return new DoubleValue(dec.doubleValue());
}
// Now apply any rounding needed, using the "round half to even" rule***CHANGE
double rem = d % 10;
if (rem >= 5) {
d += (10-rem);
} else if (rem < 5){
d -= rem;
}
// Now convert back to the original magnitude
d /= factor;
if (value < 0) {
d = -d;
}
return new DoubleValue(d);
}
/**
* Implement the XPath round-to-half-even() function
*/
public NumericValue roundHalfToEven(int scale) {
if (Double.isNaN(value)) return this;
if (Double.isInfinite(value)) return this;
if (value==0.0) return this; // handles the negative zero case
// Convert to a scaled integer, by multiplying by 10^scale
double factor = Math.pow(10, scale+1);
double d = Math.abs(value * factor);
if (Double.isInfinite(d)) {
// double arithmetic has overflowed - do it in decimal
BigDecimal dec = new BigDecimal(value);
dec = dec.setScale(scale, BigDecimal.ROUND_HALF_EVEN);
return new DoubleValue(dec.doubleValue());
}
// Now apply any rounding needed, using the "round half to even" rule
double rem = d % 10;
if (rem > 5) {
d += (10-rem);
} else if (rem < 5){
d -= rem;
} else {
// round half to even - check the last bit
if ((d % 20) == 15) {
d +=5 ;
} else {
d -=5;
}
}
// Now convert back to the original magnitude
d /= factor;
if (value < 0) {
d = -d;
}
return new DoubleValue(d);
}
/**
* Determine whether the value is negative, zero, or positive
* @return -1 if negative, 0 if zero (including negative zero) or NaN, +1 if positive
*/
public int signum() {
if (Double.isNaN(value)) {
return 0;
}
if (value > 0) return 1;
if (value == 0) return 0;
return -1;
}
/**
* Determine with the value is (double or float) negative zero
*/
@Override
public boolean isNegativeZero() {
return value == 0.0 && (Double.doubleToLongBits(value) & FloatingPointConverter.doubleSignMask) != 0;
}
/**
* Determine whether the value is a whole number, that is, whether it compares
* equal to some integer
*/
public boolean isWholeNumber() {
return value == Math.floor(value) && !Double.isInfinite(value);
}
/**
* Get the absolute value as defined by the XPath abs() function
* @return the absolute value
* @since 9.2
*/
public NumericValue abs() {
if (value > 0.0) {
return this;
} else {
return new DoubleValue(Math.abs(value));
}
}
/**
* Compare the value to a long.
* @param other the value to be compared with
* @return -1 if this is less, 0 if this is equal, +1 if this is greater or if this is NaN
*/
public int compareTo(long other) {
double otherDouble = (double)other;
if (value == otherDouble) return 0;
if (value < otherDouble) return -1;
return +1;
}
/**
* Get an object that implements XML Schema comparison semantics
*/
public Comparable getSchemaComparable() {
// convert negative to positive zero because Double.compareTo() does the wrong thing
// TODO: what shall we do with NaN?
return (value == 0.0 ? 0.0 : value);
}
/**
* Determine whether two atomic values are identical, as determined by XML Schema rules. This is a stronger
* test than equality (even schema-equality); for example two dateTime values are not identical unless
* they are in the same timezone.
* Note that even this check ignores the type annotation of the value. The integer 3 and the short 3
* are considered identical, even though they are not fully interchangeable. "Identical" means the
* same point in the value space, regardless of type annotation.
* NaN is identical to itself.
*
* @param v the other value to be compared with this one
* @return true if the two values are identical, false otherwise.
*/
public boolean isIdentical(/*@NotNull*/ AtomicValue v) {
return v instanceof DoubleValue && DoubleSortComparer.getInstance().comparesEqual(this, (DoubleValue)v);
}
/**
* Diagnostic method: print the sign, exponent, and significand
* @param d the double to be diagnosed
*/
public static void printInternalForm(double d) {
System.err.println("==== Double " + d + " ====");
long bits = Double.doubleToLongBits(d);
System.err.println("Internal form: " + Long.toHexString(bits));
if (bits == 0x7ff0000000000000L) {
System.err.println("+Infinity");
} else if (bits == 0xfff0000000000000L) {
System.err.println("-Infinity");
} else if (bits == 0x7ff8000000000000L) {
System.err.println("NaN");
} else {
int s = ((bits >> 63) == 0) ? 1 : -1;
int e = (int)((bits >> 52) & 0x7ffL);
long m = (e == 0) ?
(bits & 0xfffffffffffffL) << 1 :
(bits & 0xfffffffffffffL) | 0x10000000000000L;
int exponent = e-1075;
System.err.println("Sign: " + s);
System.err.println("Raw Exponent: " + e);
System.err.println("Exponent: " + exponent);
System.err.println("Significand: " + m);
BigDecimal dec = BigDecimal.valueOf(m);
if (exponent > 0) {
dec = dec.multiply(new BigDecimal(BigInteger.valueOf(2).pow(exponent)));
} else {
// Next line is sometimes failing, e.g. on -3.62e-5. Not investigated.
dec = dec.divide(new BigDecimal(BigInteger.valueOf(2).pow(-exponent)), BigDecimal.ROUND_HALF_EVEN);
}
System.err.println("Exact value: " + (s>0?"":"-") + dec);
}
}
public static DoubleValue fromInternalForm(String hex) {
return new DoubleValue(Double.longBitsToDouble(Long.parseLong(hex, 16)));
}
public static void main(String[] args) {
System.err.println(fromInternalForm("3fdeaee8744b05f1"));
//printInternalForm(0.4794255386042030002732879352155713880818033679406000675);
// System.err.println("3e0 : " + new DoubleValue(3e0).isWholeNumber());
// System.err.println("3e1 : " + new DoubleValue(3e1).isWholeNumber());
// System.err.println("3e-1 : " + new DoubleValue(3e-1).isWholeNumber());
// System.err.println("1e0 : " + new DoubleValue(1e0).isWholeNumber());
// System.err.println("1 - 20");
// printInternalForm(1e0);
// printInternalForm(2e0);
// printInternalForm(3e0);
// printInternalForm(4e0);
// printInternalForm(5e0);
// printInternalForm(6e0);
// printInternalForm(7e0);
// printInternalForm(8e0);
// printInternalForm(9e0);
// printInternalForm(10e0);
// printInternalForm(11e0);
// printInternalForm(12e0);
// printInternalForm(13e0);
// printInternalForm(14e0);
// printInternalForm(15e0);
// printInternalForm(16e0);
// printInternalForm(17e0);
// printInternalForm(18e0);
// printInternalForm(19e0);
// printInternalForm(20e0);
// System.err.println("3.0000001");
// printInternalForm(3.0000001e0);
// System.err.println("1");
// printInternalForm(1e0);
// System.err.println("1.00000001");
// printInternalForm(1.00000001e0);
// System.err.println("0.9999999e0");
// printInternalForm(0.9999999e0);
// System.err.println("30");
// printInternalForm(3e1);
// System.err.println("== 0.3 ==");
// printInternalForm(3e-1);
}
}