| /* |
| * Copyright (c) 1996, 2014, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved |
| * (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved |
| * |
| * The original version of this source code and documentation is copyrighted |
| * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These |
| * materials are provided under terms of a License Agreement between Taligent |
| * and Sun. This technology is protected by multiple US and International |
| * patents. This notice and attribution to Taligent may not be removed. |
| * Taligent is a registered trademark of Taligent, Inc. |
| * |
| */ |
| |
| package java.text; |
| |
| import java.math.BigDecimal; |
| import java.math.BigInteger; |
| import java.math.RoundingMode; |
| import jdk.internal.math.FloatingDecimal; |
| |
| /** |
| * Digit List. Private to DecimalFormat. |
| * Handles the transcoding |
| * between numeric values and strings of characters. Only handles |
| * non-negative numbers. The division of labor between DigitList and |
| * DecimalFormat is that DigitList handles the radix 10 representation |
| * issues; DecimalFormat handles the locale-specific issues such as |
| * positive/negative, grouping, decimal point, currency, and so on. |
| * |
| * A DigitList is really a representation of a floating point value. |
| * It may be an integer value; we assume that a double has sufficient |
| * precision to represent all digits of a long. |
| * |
| * The DigitList representation consists of a string of characters, |
| * which are the digits radix 10, from '0' to '9'. It also has a radix |
| * 10 exponent associated with it. The value represented by a DigitList |
| * object can be computed by mulitplying the fraction f, where 0 <= f < 1, |
| * derived by placing all the digits of the list to the right of the |
| * decimal point, by 10^exponent. |
| * |
| * @see Locale |
| * @see Format |
| * @see NumberFormat |
| * @see DecimalFormat |
| * @see ChoiceFormat |
| * @see MessageFormat |
| * @author Mark Davis, Alan Liu |
| */ |
| final class DigitList implements Cloneable { |
| /** |
| * The maximum number of significant digits in an IEEE 754 double, that |
| * is, in a Java double. This must not be increased, or garbage digits |
| * will be generated, and should not be decreased, or accuracy will be lost. |
| */ |
| public static final int MAX_COUNT = 19; // == Long.toString(Long.MAX_VALUE).length() |
| |
| /** |
| * These data members are intentionally public and can be set directly. |
| * |
| * The value represented is given by placing the decimal point before |
| * digits[decimalAt]. If decimalAt is < 0, then leading zeros between |
| * the decimal point and the first nonzero digit are implied. If decimalAt |
| * is > count, then trailing zeros between the digits[count-1] and the |
| * decimal point are implied. |
| * |
| * Equivalently, the represented value is given by f * 10^decimalAt. Here |
| * f is a value 0.1 <= f < 1 arrived at by placing the digits in Digits to |
| * the right of the decimal. |
| * |
| * DigitList is normalized, so if it is non-zero, figits[0] is non-zero. We |
| * don't allow denormalized numbers because our exponent is effectively of |
| * unlimited magnitude. The count value contains the number of significant |
| * digits present in digits[]. |
| * |
| * Zero is represented by any DigitList with count == 0 or with each digits[i] |
| * for all i <= count == '0'. |
| */ |
| public int decimalAt = 0; |
| public int count = 0; |
| public char[] digits = new char[MAX_COUNT]; |
| |
| private char[] data; |
| private RoundingMode roundingMode = RoundingMode.HALF_EVEN; |
| private boolean isNegative = false; |
| |
| /** |
| * Return true if the represented number is zero. |
| */ |
| boolean isZero() { |
| for (int i=0; i < count; ++i) { |
| if (digits[i] != '0') { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Set the rounding mode |
| */ |
| void setRoundingMode(RoundingMode r) { |
| roundingMode = r; |
| } |
| |
| /** |
| * Clears out the digits. |
| * Use before appending them. |
| * Typically, you set a series of digits with append, then at the point |
| * you hit the decimal point, you set myDigitList.decimalAt = myDigitList.count; |
| * then go on appending digits. |
| */ |
| public void clear () { |
| decimalAt = 0; |
| count = 0; |
| } |
| |
| /** |
| * Appends a digit to the list, extending the list when necessary. |
| */ |
| public void append(char digit) { |
| if (count == digits.length) { |
| char[] data = new char[count + 100]; |
| System.arraycopy(digits, 0, data, 0, count); |
| digits = data; |
| } |
| digits[count++] = digit; |
| } |
| |
| /** |
| * Utility routine to get the value of the digit list |
| * If (count == 0) this throws a NumberFormatException, which |
| * mimics Long.parseLong(). |
| */ |
| public final double getDouble() { |
| if (count == 0) { |
| return 0.0; |
| } |
| |
| StringBuffer temp = getStringBuffer(); |
| temp.append('.'); |
| temp.append(digits, 0, count); |
| temp.append('E'); |
| temp.append(decimalAt); |
| return Double.parseDouble(temp.toString()); |
| } |
| |
| /** |
| * Utility routine to get the value of the digit list. |
| * If (count == 0) this returns 0, unlike Long.parseLong(). |
| */ |
| public final long getLong() { |
| // for now, simple implementation; later, do proper IEEE native stuff |
| |
| if (count == 0) { |
| return 0; |
| } |
| |
| // We have to check for this, because this is the one NEGATIVE value |
| // we represent. If we tried to just pass the digits off to parseLong, |
| // we'd get a parse failure. |
| if (isLongMIN_VALUE()) { |
| return Long.MIN_VALUE; |
| } |
| |
| StringBuffer temp = getStringBuffer(); |
| temp.append(digits, 0, count); |
| for (int i = count; i < decimalAt; ++i) { |
| temp.append('0'); |
| } |
| return Long.parseLong(temp.toString()); |
| } |
| |
| public final BigDecimal getBigDecimal() { |
| if (count == 0) { |
| if (decimalAt == 0) { |
| return BigDecimal.ZERO; |
| } else { |
| return new BigDecimal("0E" + decimalAt); |
| } |
| } |
| |
| if (decimalAt == count) { |
| return new BigDecimal(digits, 0, count); |
| } else { |
| return new BigDecimal(digits, 0, count).scaleByPowerOfTen(decimalAt - count); |
| } |
| } |
| |
| /** |
| * Return true if the number represented by this object can fit into |
| * a long. |
| * @param isPositive true if this number should be regarded as positive |
| * @param ignoreNegativeZero true if -0 should be regarded as identical to |
| * +0; otherwise they are considered distinct |
| * @return true if this number fits into a Java long |
| */ |
| boolean fitsIntoLong(boolean isPositive, boolean ignoreNegativeZero) { |
| // Figure out if the result will fit in a long. We have to |
| // first look for nonzero digits after the decimal point; |
| // then check the size. If the digit count is 18 or less, then |
| // the value can definitely be represented as a long. If it is 19 |
| // then it may be too large. |
| |
| // Trim trailing zeros. This does not change the represented value. |
| while (count > 0 && digits[count - 1] == '0') { |
| --count; |
| } |
| |
| if (count == 0) { |
| // Positive zero fits into a long, but negative zero can only |
| // be represented as a double. - bug 4162852 |
| return isPositive || ignoreNegativeZero; |
| } |
| |
| if (decimalAt < count || decimalAt > MAX_COUNT) { |
| return false; |
| } |
| |
| if (decimalAt < MAX_COUNT) return true; |
| |
| // At this point we have decimalAt == count, and count == MAX_COUNT. |
| // The number will overflow if it is larger than 9223372036854775807 |
| // or smaller than -9223372036854775808. |
| for (int i=0; i<count; ++i) { |
| char dig = digits[i], max = LONG_MIN_REP[i]; |
| if (dig > max) return false; |
| if (dig < max) return true; |
| } |
| |
| // At this point the first count digits match. If decimalAt is less |
| // than count, then the remaining digits are zero, and we return true. |
| if (count < decimalAt) return true; |
| |
| // Now we have a representation of Long.MIN_VALUE, without the leading |
| // negative sign. If this represents a positive value, then it does |
| // not fit; otherwise it fits. |
| return !isPositive; |
| } |
| |
| /** |
| * Set the digit list to a representation of the given double value. |
| * This method supports fixed-point notation. |
| * @param isNegative Boolean value indicating whether the number is negative. |
| * @param source Value to be converted; must not be Inf, -Inf, Nan, |
| * or a value <= 0. |
| * @param maximumFractionDigits The most fractional digits which should |
| * be converted. |
| */ |
| final void set(boolean isNegative, double source, int maximumFractionDigits) { |
| set(isNegative, source, maximumFractionDigits, true); |
| } |
| |
| /** |
| * Set the digit list to a representation of the given double 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 Inf, -Inf, Nan, |
| * or 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, double source, int maximumDigits, boolean fixedPoint) { |
| |
| FloatingDecimal.BinaryToASCIIConverter fdConverter = FloatingDecimal.getBinaryToASCIIConverter(source); |
| boolean hasBeenRoundedUp = fdConverter.digitsRoundedUp(); |
| boolean valueExactAsDecimal = fdConverter.decimalDigitsExact(); |
| assert !fdConverter.isExceptional(); |
| String digitsString = fdConverter.toJavaFormatString(); |
| |
| set(isNegative, digitsString, |
| hasBeenRoundedUp, valueExactAsDecimal, |
| maximumDigits, fixedPoint); |
| } |
| |
| /** |
| * Generate a representation of the form DDDDD, DDDDD.DDDDD, or |
| * DDDDDE+/-DDDDD. |
| * @param roundedUp whether or not rounding up has already happened. |
| * @param valueExactAsDecimal whether or not collected digits provide |
| * an exact decimal representation of the value. |
| */ |
| private void set(boolean isNegative, String s, |
| boolean roundedUp, boolean valueExactAsDecimal, |
| int maximumDigits, boolean fixedPoint) { |
| |
| this.isNegative = isNegative; |
| int len = s.length(); |
| char[] source = getDataChars(len); |
| s.getChars(0, len, source, 0); |
| |
| decimalAt = -1; |
| count = 0; |
| int exponent = 0; |
| // Number of zeros between decimal point and first non-zero digit after |
| // decimal point, for numbers < 1. |
| int leadingZerosAfterDecimal = 0; |
| boolean nonZeroDigitSeen = false; |
| |
| for (int i = 0; i < len; ) { |
| char c = source[i++]; |
| if (c == '.') { |
| decimalAt = count; |
| } else if (c == 'e' || c == 'E') { |
| exponent = parseInt(source, i, len); |
| break; |
| } else { |
| if (!nonZeroDigitSeen) { |
| nonZeroDigitSeen = (c != '0'); |
| if (!nonZeroDigitSeen && decimalAt != -1) |
| ++leadingZerosAfterDecimal; |
| } |
| if (nonZeroDigitSeen) { |
| digits[count++] = c; |
| } |
| } |
| } |
| if (decimalAt == -1) { |
| decimalAt = count; |
| } |
| if (nonZeroDigitSeen) { |
| decimalAt += exponent - leadingZerosAfterDecimal; |
| } |
| |
| if (fixedPoint) { |
| // The negative of the exponent represents the number of leading |
| // zeros between the decimal and the first non-zero digit, for |
| // a value < 0.1 (e.g., for 0.00123, -decimalAt == 2). If this |
| // is more than the maximum fraction digits, then we have an underflow |
| // for the printed representation. |
| if (-decimalAt > maximumDigits) { |
| // Handle an underflow to zero when we round something like |
| // 0.0009 to 2 fractional digits. |
| count = 0; |
| return; |
| } else if (-decimalAt == maximumDigits) { |
| // If we round 0.0009 to 3 fractional digits, then we have to |
| // create a new one digit in the least significant location. |
| if (shouldRoundUp(0, roundedUp, valueExactAsDecimal)) { |
| count = 1; |
| ++decimalAt; |
| digits[0] = '1'; |
| } else { |
| count = 0; |
| } |
| return; |
| } |
| // else fall through |
| } |
| |
| // Eliminate trailing zeros. |
| while (count > 1 && digits[count - 1] == '0') { |
| --count; |
| } |
| |
| // Eliminate digits beyond maximum digits to be displayed. |
| // Round up if appropriate. |
| round(fixedPoint ? (maximumDigits + decimalAt) : maximumDigits, |
| roundedUp, valueExactAsDecimal); |
| |
| } |
| |
| /** |
| * Round the representation to the given number of digits. |
| * @param maximumDigits The maximum number of digits to be shown. |
| * @param alreadyRounded whether or not rounding up has already happened. |
| * @param valueExactAsDecimal whether or not collected digits provide |
| * an exact decimal representation of the value. |
| * |
| * Upon return, count will be less than or equal to maximumDigits. |
| */ |
| private final void round(int maximumDigits, |
| boolean alreadyRounded, |
| boolean valueExactAsDecimal) { |
| // Eliminate digits beyond maximum digits to be displayed. |
| // Round up if appropriate. |
| if (maximumDigits >= 0 && maximumDigits < count) { |
| if (shouldRoundUp(maximumDigits, alreadyRounded, valueExactAsDecimal)) { |
| // Rounding up involved incrementing digits from LSD to MSD. |
| // In most cases this is simple, but in a worst case situation |
| // (9999..99) we have to adjust the decimalAt value. |
| for (;;) { |
| --maximumDigits; |
| if (maximumDigits < 0) { |
| // We have all 9's, so we increment to a single digit |
| // of one and adjust the exponent. |
| digits[0] = '1'; |
| ++decimalAt; |
| maximumDigits = 0; // Adjust the count |
| break; |
| } |
| |
| ++digits[maximumDigits]; |
| if (digits[maximumDigits] <= '9') break; |
| // digits[maximumDigits] = '0'; // Unnecessary since we'll truncate this |
| } |
| ++maximumDigits; // Increment for use as count |
| } |
| count = maximumDigits; |
| |
| // Eliminate trailing zeros. |
| while (count > 1 && digits[count-1] == '0') { |
| --count; |
| } |
| } |
| } |
| |
| |
| /** |
| * Return true if truncating the representation to the given number |
| * of digits will result in an increment to the last digit. This |
| * method implements the rounding modes defined in the |
| * java.math.RoundingMode class. |
| * [bnf] |
| * @param maximumDigits the number of digits to keep, from 0 to |
| * <code>count-1</code>. If 0, then all digits are rounded away, and |
| * this method returns true if a one should be generated (e.g., formatting |
| * 0.09 with "#.#"). |
| * @param alreadyRounded whether or not rounding up has already happened. |
| * @param valueExactAsDecimal whether or not collected digits provide |
| * an exact decimal representation of the value. |
| * @exception ArithmeticException if rounding is needed with rounding |
| * mode being set to RoundingMode.UNNECESSARY |
| * @return true if digit <code>maximumDigits-1</code> should be |
| * incremented |
| */ |
| private boolean shouldRoundUp(int maximumDigits, |
| boolean alreadyRounded, |
| boolean valueExactAsDecimal) { |
| if (maximumDigits < count) { |
| /* |
| * To avoid erroneous double-rounding or truncation when converting |
| * a binary double value to text, information about the exactness |
| * of the conversion result in FloatingDecimal, as well as any |
| * rounding done, is needed in this class. |
| * |
| * - For the HALF_DOWN, HALF_EVEN, HALF_UP rounding rules below: |
| * In the case of formating float or double, We must take into |
| * account what FloatingDecimal has done in the binary to decimal |
| * conversion. |
| * |
| * Considering the tie cases, FloatingDecimal may round up the |
| * value (returning decimal digits equal to tie when it is below), |
| * or "truncate" the value to the tie while value is above it, |
| * or provide the exact decimal digits when the binary value can be |
| * converted exactly to its decimal representation given formating |
| * rules of FloatingDecimal ( we have thus an exact decimal |
| * representation of the binary value). |
| * |
| * - If the double binary value was converted exactly as a decimal |
| * value, then DigitList code must apply the expected rounding |
| * rule. |
| * |
| * - If FloatingDecimal already rounded up the decimal value, |
| * DigitList should neither round up the value again in any of |
| * the three rounding modes above. |
| * |
| * - If FloatingDecimal has truncated the decimal value to |
| * an ending '5' digit, DigitList should round up the value in |
| * all of the three rounding modes above. |
| * |
| * |
| * This has to be considered only if digit at maximumDigits index |
| * is exactly the last one in the set of digits, otherwise there are |
| * remaining digits after that position and we don't have to consider |
| * what FloatingDecimal did. |
| * |
| * - Other rounding modes are not impacted by these tie cases. |
| * |
| * - For other numbers that are always converted to exact digits |
| * (like BigInteger, Long, ...), the passed alreadyRounded boolean |
| * have to be set to false, and valueExactAsDecimal has to be set to |
| * true in the upper DigitList call stack, providing the right state |
| * for those situations.. |
| */ |
| |
| switch(roundingMode) { |
| case UP: |
| for (int i=maximumDigits; i<count; ++i) { |
| if (digits[i] != '0') { |
| return true; |
| } |
| } |
| break; |
| case DOWN: |
| break; |
| case CEILING: |
| for (int i=maximumDigits; i<count; ++i) { |
| if (digits[i] != '0') { |
| return !isNegative; |
| } |
| } |
| break; |
| case FLOOR: |
| for (int i=maximumDigits; i<count; ++i) { |
| if (digits[i] != '0') { |
| return isNegative; |
| } |
| } |
| break; |
| case HALF_UP: |
| case HALF_DOWN: |
| if (digits[maximumDigits] > '5') { |
| // Value is above tie ==> must round up |
| return true; |
| } else if (digits[maximumDigits] == '5') { |
| // Digit at rounding position is a '5'. Tie cases. |
| if (maximumDigits != (count - 1)) { |
| // There are remaining digits. Above tie => must round up |
| return true; |
| } else { |
| // Digit at rounding position is the last one ! |
| if (valueExactAsDecimal) { |
| // Exact binary representation. On the tie. |
| // Apply rounding given by roundingMode. |
| return roundingMode == RoundingMode.HALF_UP; |
| } else { |
| // Not an exact binary representation. |
| // Digit sequence either rounded up or truncated. |
| // Round up only if it was truncated. |
| return !alreadyRounded; |
| } |
| } |
| } |
| // Digit at rounding position is < '5' ==> no round up. |
| // Just let do the default, which is no round up (thus break). |
| break; |
| case HALF_EVEN: |
| // Implement IEEE half-even rounding |
| if (digits[maximumDigits] > '5') { |
| return true; |
| } else if (digits[maximumDigits] == '5' ) { |
| if (maximumDigits == (count - 1)) { |
| // the rounding position is exactly the last index : |
| if (alreadyRounded) |
| // If FloatingDecimal rounded up (value was below tie), |
| // then we should not round up again. |
| return false; |
| |
| if (!valueExactAsDecimal) |
| // Otherwise if the digits don't represent exact value, |
| // value was above tie and FloatingDecimal truncated |
| // digits to tie. We must round up. |
| return true; |
| else { |
| // This is an exact tie value, and FloatingDecimal |
| // provided all of the exact digits. We thus apply |
| // HALF_EVEN rounding rule. |
| return ((maximumDigits > 0) && |
| (digits[maximumDigits-1] % 2 != 0)); |
| } |
| } else { |
| // Rounds up if it gives a non null digit after '5' |
| for (int i=maximumDigits+1; i<count; ++i) { |
| if (digits[i] != '0') |
| return true; |
| } |
| } |
| } |
| break; |
| case UNNECESSARY: |
| for (int i=maximumDigits; i<count; ++i) { |
| if (digits[i] != '0') { |
| throw new ArithmeticException( |
| "Rounding needed with the rounding mode being set to RoundingMode.UNNECESSARY"); |
| } |
| } |
| break; |
| default: |
| assert false; |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * Utility routine to set the value of the digit list from a long |
| */ |
| final void set(boolean isNegative, long source) { |
| set(isNegative, source, 0); |
| } |
| |
| /** |
| * Set the digit list to a representation of the given long value. |
| * @param isNegative Boolean value indicating whether the number is negative. |
| * @param source Value to be converted; must be >= 0 or == |
| * Long.MIN_VALUE. |
| * @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, long source, int maximumDigits) { |
| this.isNegative = isNegative; |
| |
| // This method does not expect a negative number. However, |
| // "source" can be a Long.MIN_VALUE (-9223372036854775808), |
| // if the number being formatted is a Long.MIN_VALUE. In that |
| // 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, false, true); |
| } |
| |
| /** |
| * 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, |
| false, true, |
| 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, false, true); |
| } |
| } |
| |
| /** |
| * 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(e); |
| } |
| } |
| |
| /** |
| * 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; |
| } |
| } |