716 lines
25 KiB
Java
716 lines
25 KiB
Java
/*
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* Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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/*
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* (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
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* (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved
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*
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* The original version of this source code and documentation is copyrighted
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* and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
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* materials are provided under terms of a License Agreement between Taligent
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* and Sun. This technology is protected by multiple US and International
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* patents. This notice and attribution to Taligent may not be removed.
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* Taligent is a registered trademark of Taligent, Inc.
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*
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*/
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package java.text;
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import java.math.BigDecimal;
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import java.math.BigInteger;
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import java.math.RoundingMode;
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/**
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* Digit List. Private to DecimalFormat.
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* Handles the transcoding
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* between numeric values and strings of characters. Only handles
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* non-negative numbers. The division of labor between DigitList and
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* DecimalFormat is that DigitList handles the radix 10 representation
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* issues; DecimalFormat handles the locale-specific issues such as
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* positive/negative, grouping, decimal point, currency, and so on.
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*
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* A DigitList is really a representation of a floating point value.
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* It may be an integer value; we assume that a double has sufficient
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* precision to represent all digits of a long.
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*
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* The DigitList representation consists of a string of characters,
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* which are the digits radix 10, from '0' to '9'. It also has a radix
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* 10 exponent associated with it. The value represented by a DigitList
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* object can be computed by mulitplying the fraction f, where 0 <= f < 1,
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* derived by placing all the digits of the list to the right of the
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* decimal point, by 10^exponent.
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*
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* @see Locale
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* @see Format
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* @see NumberFormat
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* @see DecimalFormat
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* @see ChoiceFormat
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* @see MessageFormat
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* @author Mark Davis, Alan Liu
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*/
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final class DigitList implements Cloneable {
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/**
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* The maximum number of significant digits in an IEEE 754 double, that
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* is, in a Java double. This must not be increased, or garbage digits
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* will be generated, and should not be decreased, or accuracy will be lost.
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*/
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public static final int MAX_COUNT = 19; // == Long.toString(Long.MAX_VALUE).length()
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/**
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* These data members are intentionally public and can be set directly.
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*
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* The value represented is given by placing the decimal point before
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* digits[decimalAt]. If decimalAt is < 0, then leading zeros between
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* the decimal point and the first nonzero digit are implied. If decimalAt
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* is > count, then trailing zeros between the digits[count-1] and the
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* decimal point are implied.
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*
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* Equivalently, the represented value is given by f * 10^decimalAt. Here
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* f is a value 0.1 <= f < 1 arrived at by placing the digits in Digits to
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* the right of the decimal.
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*
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* DigitList is normalized, so if it is non-zero, figits[0] is non-zero. We
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* don't allow denormalized numbers because our exponent is effectively of
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* unlimited magnitude. The count value contains the number of significant
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* digits present in digits[].
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*
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* Zero is represented by any DigitList with count == 0 or with each digits[i]
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* for all i <= count == '0'.
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*/
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public int decimalAt = 0;
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public int count = 0;
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public char[] digits = new char[MAX_COUNT];
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private char[] data;
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private RoundingMode roundingMode = RoundingMode.HALF_EVEN;
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private boolean isNegative = false;
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/**
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* Return true if the represented number is zero.
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*/
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boolean isZero() {
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for (int i=0; i < count; ++i) {
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if (digits[i] != '0') {
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return false;
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}
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}
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return true;
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}
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/**
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* Set the rounding mode
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*/
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void setRoundingMode(RoundingMode r) {
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roundingMode = r;
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}
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/**
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* Clears out the digits.
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* Use before appending them.
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* Typically, you set a series of digits with append, then at the point
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* you hit the decimal point, you set myDigitList.decimalAt = myDigitList.count;
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* then go on appending digits.
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*/
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public void clear () {
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decimalAt = 0;
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count = 0;
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}
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/**
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* Appends a digit to the list, extending the list when necessary.
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*/
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public void append(char digit) {
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if (count == digits.length) {
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char[] data = new char[count + 100];
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System.arraycopy(digits, 0, data, 0, count);
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digits = data;
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}
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digits[count++] = digit;
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}
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/**
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* Utility routine to get the value of the digit list
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* If (count == 0) this throws a NumberFormatException, which
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* mimics Long.parseLong().
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*/
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public final double getDouble() {
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if (count == 0) {
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return 0.0;
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}
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StringBuffer temp = getStringBuffer();
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temp.append('.');
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temp.append(digits, 0, count);
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temp.append('E');
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temp.append(decimalAt);
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return Double.parseDouble(temp.toString());
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}
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/**
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* Utility routine to get the value of the digit list.
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* If (count == 0) this returns 0, unlike Long.parseLong().
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*/
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public final long getLong() {
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// for now, simple implementation; later, do proper IEEE native stuff
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if (count == 0) {
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return 0;
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}
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// We have to check for this, because this is the one NEGATIVE value
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// we represent. If we tried to just pass the digits off to parseLong,
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// we'd get a parse failure.
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if (isLongMIN_VALUE()) {
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return Long.MIN_VALUE;
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}
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StringBuffer temp = getStringBuffer();
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temp.append(digits, 0, count);
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for (int i = count; i < decimalAt; ++i) {
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temp.append('0');
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}
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return Long.parseLong(temp.toString());
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}
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public final BigDecimal getBigDecimal() {
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if (count == 0) {
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if (decimalAt == 0) {
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return BigDecimal.ZERO;
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} else {
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return new BigDecimal("0E" + decimalAt);
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}
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}
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if (decimalAt == count) {
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return new BigDecimal(digits, 0, count);
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} else {
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return new BigDecimal(digits, 0, count).scaleByPowerOfTen(decimalAt - count);
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}
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}
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/**
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* Return true if the number represented by this object can fit into
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* a long.
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* @param isPositive true if this number should be regarded as positive
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* @param ignoreNegativeZero true if -0 should be regarded as identical to
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* +0; otherwise they are considered distinct
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* @return true if this number fits into a Java long
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*/
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boolean fitsIntoLong(boolean isPositive, boolean ignoreNegativeZero) {
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// Figure out if the result will fit in a long. We have to
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// first look for nonzero digits after the decimal point;
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// then check the size. If the digit count is 18 or less, then
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// the value can definitely be represented as a long. If it is 19
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// then it may be too large.
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// Trim trailing zeros. This does not change the represented value.
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while (count > 0 && digits[count - 1] == '0') {
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--count;
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}
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if (count == 0) {
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// Positive zero fits into a long, but negative zero can only
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// be represented as a double. - bug 4162852
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return isPositive || ignoreNegativeZero;
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}
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if (decimalAt < count || decimalAt > MAX_COUNT) {
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return false;
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}
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if (decimalAt < MAX_COUNT) return true;
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// At this point we have decimalAt == count, and count == MAX_COUNT.
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// The number will overflow if it is larger than 9223372036854775807
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// or smaller than -9223372036854775808.
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for (int i=0; i<count; ++i) {
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char dig = digits[i], max = LONG_MIN_REP[i];
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if (dig > max) return false;
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if (dig < max) return true;
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}
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// At this point the first count digits match. If decimalAt is less
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// than count, then the remaining digits are zero, and we return true.
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if (count < decimalAt) return true;
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// Now we have a representation of Long.MIN_VALUE, without the leading
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// negative sign. If this represents a positive value, then it does
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// not fit; otherwise it fits.
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return !isPositive;
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}
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/**
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* Set the digit list to a representation of the given double value.
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* This method supports fixed-point notation.
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* @param isNegative Boolean value indicating whether the number is negative.
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* @param source Value to be converted; must not be Inf, -Inf, Nan,
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* or a value <= 0.
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* @param maximumFractionDigits The most fractional digits which should
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* be converted.
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*/
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public final void set(boolean isNegative, double source, int maximumFractionDigits) {
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set(isNegative, source, maximumFractionDigits, true);
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}
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/**
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* Set the digit list to a representation of the given double value.
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* This method supports both fixed-point and exponential notation.
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* @param isNegative Boolean value indicating whether the number is negative.
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* @param source Value to be converted; must not be Inf, -Inf, Nan,
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* or a value <= 0.
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* @param maximumDigits The most fractional or total digits which should
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* be converted.
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* @param fixedPoint If true, then maximumDigits is the maximum
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* fractional digits to be converted. If false, total digits.
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*/
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final void set(boolean isNegative, double source, int maximumDigits, boolean fixedPoint) {
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set(isNegative, Double.toString(source), maximumDigits, fixedPoint);
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}
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/**
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* Generate a representation of the form DDDDD, DDDDD.DDDDD, or
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* DDDDDE+/-DDDDD.
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*/
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final void set(boolean isNegative, String s, int maximumDigits, boolean fixedPoint) {
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this.isNegative = isNegative;
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int len = s.length();
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char[] source = getDataChars(len);
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s.getChars(0, len, source, 0);
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decimalAt = -1;
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count = 0;
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int exponent = 0;
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// Number of zeros between decimal point and first non-zero digit after
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// decimal point, for numbers < 1.
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int leadingZerosAfterDecimal = 0;
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boolean nonZeroDigitSeen = false;
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for (int i = 0; i < len; ) {
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char c = source[i++];
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if (c == '.') {
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decimalAt = count;
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} else if (c == 'e' || c == 'E') {
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exponent = parseInt(source, i, len);
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break;
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} else {
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if (!nonZeroDigitSeen) {
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nonZeroDigitSeen = (c != '0');
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if (!nonZeroDigitSeen && decimalAt != -1)
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++leadingZerosAfterDecimal;
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}
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if (nonZeroDigitSeen) {
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digits[count++] = c;
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}
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}
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}
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if (decimalAt == -1) {
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decimalAt = count;
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}
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if (nonZeroDigitSeen) {
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decimalAt += exponent - leadingZerosAfterDecimal;
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}
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if (fixedPoint) {
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// The negative of the exponent represents the number of leading
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// zeros between the decimal and the first non-zero digit, for
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// a value < 0.1 (e.g., for 0.00123, -decimalAt == 2). If this
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// is more than the maximum fraction digits, then we have an underflow
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// for the printed representation.
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if (-decimalAt > maximumDigits) {
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// Handle an underflow to zero when we round something like
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// 0.0009 to 2 fractional digits.
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count = 0;
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return;
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} else if (-decimalAt == maximumDigits) {
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// If we round 0.0009 to 3 fractional digits, then we have to
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// create a new one digit in the least significant location.
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if (shouldRoundUp(0)) {
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count = 1;
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++decimalAt;
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digits[0] = '1';
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} else {
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count = 0;
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}
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return;
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}
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// else fall through
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}
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// Eliminate trailing zeros.
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while (count > 1 && digits[count - 1] == '0') {
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--count;
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}
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// Eliminate digits beyond maximum digits to be displayed.
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// Round up if appropriate.
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round(fixedPoint ? (maximumDigits + decimalAt) : maximumDigits);
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}
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/**
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* Round the representation to the given number of digits.
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* @param maximumDigits The maximum number of digits to be shown.
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* Upon return, count will be less than or equal to maximumDigits.
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*/
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private final void round(int maximumDigits) {
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// Eliminate digits beyond maximum digits to be displayed.
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// Round up if appropriate.
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if (maximumDigits >= 0 && maximumDigits < count) {
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if (shouldRoundUp(maximumDigits)) {
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// Rounding up involved incrementing digits from LSD to MSD.
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// In most cases this is simple, but in a worst case situation
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// (9999..99) we have to adjust the decimalAt value.
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for (;;) {
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--maximumDigits;
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if (maximumDigits < 0) {
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// We have all 9's, so we increment to a single digit
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// of one and adjust the exponent.
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digits[0] = '1';
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++decimalAt;
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maximumDigits = 0; // Adjust the count
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break;
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}
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++digits[maximumDigits];
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if (digits[maximumDigits] <= '9') break;
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// digits[maximumDigits] = '0'; // Unnecessary since we'll truncate this
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}
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++maximumDigits; // Increment for use as count
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}
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count = maximumDigits;
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// Eliminate trailing zeros.
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while (count > 1 && digits[count-1] == '0') {
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--count;
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}
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}
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}
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/**
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* Return true if truncating the representation to the given number
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* of digits will result in an increment to the last digit. This
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* method implements the rounding modes defined in the
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* java.math.RoundingMode class.
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* [bnf]
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* @param maximumDigits the number of digits to keep, from 0 to
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* <code>count-1</code>. If 0, then all digits are rounded away, and
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* this method returns true if a one should be generated (e.g., formatting
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* 0.09 with "#.#").
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* @exception ArithmeticException if rounding is needed with rounding
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* mode being set to RoundingMode.UNNECESSARY
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* @return true if digit <code>maximumDigits-1</code> should be
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* incremented
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*/
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private boolean shouldRoundUp(int maximumDigits) {
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if (maximumDigits < count) {
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switch(roundingMode) {
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case UP:
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for (int i=maximumDigits; i<count; ++i) {
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if (digits[i] != '0') {
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return true;
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}
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}
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break;
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case DOWN:
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break;
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case CEILING:
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for (int i=maximumDigits; i<count; ++i) {
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if (digits[i] != '0') {
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return !isNegative;
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}
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}
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break;
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case FLOOR:
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for (int i=maximumDigits; i<count; ++i) {
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if (digits[i] != '0') {
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return isNegative;
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}
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}
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break;
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case HALF_UP:
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if (digits[maximumDigits] >= '5') {
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return true;
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}
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break;
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case HALF_DOWN:
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if (digits[maximumDigits] > '5') {
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return true;
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} else if (digits[maximumDigits] == '5' ) {
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for (int i=maximumDigits+1; i<count; ++i) {
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if (digits[i] != '0') {
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return true;
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}
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}
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}
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break;
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case HALF_EVEN:
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// Implement IEEE half-even rounding
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if (digits[maximumDigits] > '5') {
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return true;
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} else if (digits[maximumDigits] == '5' ) {
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for (int i=maximumDigits+1; i<count; ++i) {
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if (digits[i] != '0') {
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return true;
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}
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}
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return maximumDigits > 0 && (digits[maximumDigits-1] % 2 != 0);
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}
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break;
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case UNNECESSARY:
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for (int i=maximumDigits; i<count; ++i) {
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if (digits[i] != '0') {
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throw new ArithmeticException(
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"Rounding needed with the rounding mode being set to RoundingMode.UNNECESSARY");
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}
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}
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break;
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default:
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assert false;
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}
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}
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return false;
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}
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/**
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* Utility routine to set the value of the digit list from a long
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*/
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public final void set(boolean isNegative, long source) {
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set(isNegative, source, 0);
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}
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/**
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* Set the digit list to a representation of the given long value.
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* @param isNegative Boolean value indicating whether the number is negative.
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* @param source Value to be converted; must be >= 0 or ==
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* Long.MIN_VALUE.
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* @param maximumDigits The most digits which should be converted.
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* If maximumDigits is lower than the number of significant digits
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* in source, the representation will be rounded. Ignored if <= 0.
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*/
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public final void set(boolean isNegative, long source, int maximumDigits) {
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this.isNegative = isNegative;
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// This method does not expect a negative number. However,
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// "source" can be a Long.MIN_VALUE (-9223372036854775808),
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// if the number being formatted is a Long.MIN_VALUE. In that
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// case, it will be formatted as -Long.MIN_VALUE, a number
|
|
// which is outside the legal range of a long, but which can
|
|
// be represented by DigitList.
|
|
if (source <= 0) {
|
|
if (source == Long.MIN_VALUE) {
|
|
decimalAt = count = MAX_COUNT;
|
|
System.arraycopy(LONG_MIN_REP, 0, digits, 0, count);
|
|
} else {
|
|
decimalAt = count = 0; // Values <= 0 format as zero
|
|
}
|
|
} else {
|
|
// Rewritten to improve performance. I used to call
|
|
// Long.toString(), which was about 4x slower than this code.
|
|
int left = MAX_COUNT;
|
|
int right;
|
|
while (source > 0) {
|
|
digits[--left] = (char)('0' + (source % 10));
|
|
source /= 10;
|
|
}
|
|
decimalAt = MAX_COUNT - left;
|
|
// Don't copy trailing zeros. We are guaranteed that there is at
|
|
// least one non-zero digit, so we don't have to check lower bounds.
|
|
for (right = MAX_COUNT - 1; digits[right] == '0'; --right)
|
|
;
|
|
count = right - left + 1;
|
|
System.arraycopy(digits, left, digits, 0, count);
|
|
}
|
|
if (maximumDigits > 0) round(maximumDigits);
|
|
}
|
|
|
|
/**
|
|
* Set the digit list to a representation of the given BigDecimal value.
|
|
* This method supports both fixed-point and exponential notation.
|
|
* @param isNegative Boolean value indicating whether the number is negative.
|
|
* @param source Value to be converted; must not be a value <= 0.
|
|
* @param maximumDigits The most fractional or total digits which should
|
|
* be converted.
|
|
* @param fixedPoint If true, then maximumDigits is the maximum
|
|
* fractional digits to be converted. If false, total digits.
|
|
*/
|
|
final void set(boolean isNegative, BigDecimal source, int maximumDigits, boolean fixedPoint) {
|
|
String s = source.toString();
|
|
extendDigits(s.length());
|
|
|
|
set(isNegative, s, maximumDigits, fixedPoint);
|
|
}
|
|
|
|
/**
|
|
* Set the digit list to a representation of the given BigInteger value.
|
|
* @param isNegative Boolean value indicating whether the number is negative.
|
|
* @param source Value to be converted; must be >= 0.
|
|
* @param maximumDigits The most digits which should be converted.
|
|
* If maximumDigits is lower than the number of significant digits
|
|
* in source, the representation will be rounded. Ignored if <= 0.
|
|
*/
|
|
final void set(boolean isNegative, BigInteger source, int maximumDigits) {
|
|
this.isNegative = isNegative;
|
|
String s = source.toString();
|
|
int len = s.length();
|
|
extendDigits(len);
|
|
s.getChars(0, len, digits, 0);
|
|
|
|
decimalAt = len;
|
|
int right;
|
|
for (right = len - 1; right >= 0 && digits[right] == '0'; --right)
|
|
;
|
|
count = right + 1;
|
|
|
|
if (maximumDigits > 0) {
|
|
round(maximumDigits);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* equality test between two digit lists.
|
|
*/
|
|
public boolean equals(Object obj) {
|
|
if (this == obj) // quick check
|
|
return true;
|
|
if (!(obj instanceof DigitList)) // (1) same object?
|
|
return false;
|
|
DigitList other = (DigitList) obj;
|
|
if (count != other.count ||
|
|
decimalAt != other.decimalAt)
|
|
return false;
|
|
for (int i = 0; i < count; i++)
|
|
if (digits[i] != other.digits[i])
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Generates the hash code for the digit list.
|
|
*/
|
|
public int hashCode() {
|
|
int hashcode = decimalAt;
|
|
|
|
for (int i = 0; i < count; i++) {
|
|
hashcode = hashcode * 37 + digits[i];
|
|
}
|
|
|
|
return hashcode;
|
|
}
|
|
|
|
/**
|
|
* Creates a copy of this object.
|
|
* @return a clone of this instance.
|
|
*/
|
|
public Object clone() {
|
|
try {
|
|
DigitList other = (DigitList) super.clone();
|
|
char[] newDigits = new char[digits.length];
|
|
System.arraycopy(digits, 0, newDigits, 0, digits.length);
|
|
other.digits = newDigits;
|
|
other.tempBuffer = null;
|
|
return other;
|
|
} catch (CloneNotSupportedException e) {
|
|
throw new InternalError();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns true if this DigitList represents Long.MIN_VALUE;
|
|
* false, otherwise. This is required so that getLong() works.
|
|
*/
|
|
private boolean isLongMIN_VALUE() {
|
|
if (decimalAt != count || count != MAX_COUNT) {
|
|
return false;
|
|
}
|
|
|
|
for (int i = 0; i < count; ++i) {
|
|
if (digits[i] != LONG_MIN_REP[i]) return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
private static final int parseInt(char[] str, int offset, int strLen) {
|
|
char c;
|
|
boolean positive = true;
|
|
if ((c = str[offset]) == '-') {
|
|
positive = false;
|
|
offset++;
|
|
} else if (c == '+') {
|
|
offset++;
|
|
}
|
|
|
|
int value = 0;
|
|
while (offset < strLen) {
|
|
c = str[offset++];
|
|
if (c >= '0' && c <= '9') {
|
|
value = value * 10 + (c - '0');
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
return positive ? value : -value;
|
|
}
|
|
|
|
// The digit part of -9223372036854775808L
|
|
private static final char[] LONG_MIN_REP = "9223372036854775808".toCharArray();
|
|
|
|
public String toString() {
|
|
if (isZero()) {
|
|
return "0";
|
|
}
|
|
StringBuffer buf = getStringBuffer();
|
|
buf.append("0.");
|
|
buf.append(digits, 0, count);
|
|
buf.append("x10^");
|
|
buf.append(decimalAt);
|
|
return buf.toString();
|
|
}
|
|
|
|
private StringBuffer tempBuffer;
|
|
|
|
private StringBuffer getStringBuffer() {
|
|
if (tempBuffer == null) {
|
|
tempBuffer = new StringBuffer(MAX_COUNT);
|
|
} else {
|
|
tempBuffer.setLength(0);
|
|
}
|
|
return tempBuffer;
|
|
}
|
|
|
|
private void extendDigits(int len) {
|
|
if (len > digits.length) {
|
|
digits = new char[len];
|
|
}
|
|
}
|
|
|
|
private final char[] getDataChars(int length) {
|
|
if (data == null || data.length < length) {
|
|
data = new char[length];
|
|
}
|
|
return data;
|
|
}
|
|
}
|